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Final Report - BME - University of Connecticut

1. Easel Extension Base Square aluminum tube 75 x 75 x 062 3 24 total 72 Architectural Angle 5 x 5 x 0625 2 4 4 24 4 12 1 12 total 164 Sheet Metal 0625 thick 2 12 x 24 1 4 x 24 1 12 x 12 2 2 x 12 Dimensional Aluminum Needed Architectural Angle 2 8 ft 5 x 5 x 0625 12 16 Sheet Metal 2 24 x 48 x 1 16 61 92 1 12 x 12 x 1 16 8 87 oquare aluminum tube 75 x 75 x 062 3 8 36 48 Total Aluminum Cost 119 43 Light Pack of 10 super bright LEDs 15 50 L1 0 W5TH15 1 Resistors wiring switch plastic mount hinge Estimate 10 00 29 Others 2 Extension Lock Gas Spring 114 72 Rubber strips for canvas holder 2 22 2 Retractable Spring Plungers 31 80 Miscellaneous hardware 10 00 Welding Time 10 hour estimate 100 00 Total Cost Estimate 403 60 This estimated total cost of 403 60 is well below the budget of 750 set by the National science foundation 2 3 Prototype SUBUNITS LED Light SM Adjustable Hinge On Off Switch LED Light Power Source The battery is a 9 6 volt battery pack It operates at 1700mAh and is a nickel cadmium power supply It is configured as a flat stick pack with the dimensions 180 X 22 X 45 mm It also has a standard tamiya connector and includes a 12 volt battery pack charger for use in any standard wall socket The battery fully charges in 8 5 hours
2. Its run time is approximately 6 hours Its input is AC 120 V at 60Hz and its output is DC 12V 200mA LEDs The LED s are super bright 5mm White 18 000mcd They are some of the brightest white LEDs available on the market today They are energy efficient as far as how much power they dissipate They often dissipate less than 100 mill watts of power Their useable life is longer than 100 000 hours which ensures years of use with 30 reasonable use The way the LED works is fairly simple It is a PN junction semiconductor embedded in an epoxy matrix This leaves no loose or moving parts to break When current is applied the diode emits light of a certain intensity based on the magnitude of the current Most LEDs operate on a current of 20 mA this circuit operates on 25 mA This current magnitude creates a brightness of 18 000 mcd This is the recommended brightness for art display in a gallery Eye safety for an LED this bright becomes an important factor In order to avoid this problem LEDs with a luminous angle of 15 degrees were chosen Also the way the friction hinge was installed does not allow the LED enclosure to adjust in the direction of the user Also the dimming switch allows for a variable brightness A further feature of the LED light is the low heat dissipation This ensures the LEDs will not get too hot to cause a safety concern LED Spec Product ID Angle Package Color Peak Wavelength in nm Luminous Intensity Max Forwar
3. 2 5Fp Y4M A We 0 2 5Fp Wg V4 MA Fp 0 4Wg 40 1 Ma 4 Substituting values into 4 Fo 0 4Wg 40 1 Ma Fp 0 4 5 723 0 1 117 143 Fp 9 4251 lbs Using Fp in 3 to solve for Fe FE 5Fp AMA Fe 1 5 9 4251 W4 117 143 Fe z 15 148 Ibs 25 Easel Extension Analysis The easel extension arms need to be examined to ensure that the materials used would stand up to the weight and forces applied to it with reasonable use To do this the moments were calculated at each joint pin so that the bending stress could be examined The moments at each point will also be useful for the calculation of the necessary gas spring strengths needed to support the structure when it is fully extended toward the artist This particular design should be able to reach a maximum extension of 36 40 toward the artist and away from the table Shown below is a free body diagram used for the moment calculations 24 00 26 00 9 3 S gt 9 24 00 z Ueag jo 1u6leAA Z Note JepjoH seA ue JO yfl M Est Painting V All lengths are in inches 4 weg jo Jubliem 16 89 gt Figure 14 Free body diagram used for the moment calculations 26 The following table displays calculated moments at points C B and A Moment about B variable value units Sum moments Mb Mc Mb2 aboutB 0 Mcm Moment
4. There are few things that need to be done to the easel for maintenance The easel is fairly self sustaining and with some regular maintenance it can be kept functional for a very long time The easel should be maintained on three different time scales Regular Maintenance Long Term Maintenance and Case Specific Maintenance are the three categories of maintenance needed Regular Maintenance Battery Source If the easel is used everyday then the battery source will need to be recharged everyday or every other day This is a simple procedure that is explained in detail in the Ease Use section of the manual Cleaning Cleaning the easel of paint supplies can be done with a store bought cleaning supply designed for art supplies Keeping the easel clean will ensure it adjusts properly and the sliding pivoting motion will be maintained Try to keep slots in the easel frame free from debris Long Term Maintenance Battery The battery has been designed to have a very long life time however if the battery has reached the end of its expendable life than a new 9 6 V battery pack can be purchased This can be purchased from www Onlybatteries com This will be covered in the table at the end of maintenance Mechanical Function Not much else can be done to maintain the frame of the easel besides keeping it clean This will ensure that the joints keep their movement and adjustability DO NOT OIL THE JOINTS This will only impede the function
5. a table top Pivoting joints Ability to tilt and project toward the artist To hold canvas in place To remain immobile during artist use Ability to hold canvases ranging from 8 x8 to 20 x20 750 83
6. about C Mc 65 bs in Moment created by weight of Beam 2 Mb2 Wb2 Db2b 4 453056 lbs in Moment created by weight of Canvas Mcm Mount Wem DemB 41 39254 lbs in Moment B 110 8456 lbs in 117 1432 lbs in 27 To lock the canvas holder in place so it does not tilt freely a screw locking mechanism is employed as mentioned before This type of mechanism should adequately counter the moment created by the estimated painting force To account for the moment about points B and A gas springs will be used to stabilize the arm and lock it in place The following is a table with the minimum amount of force needed to be supplied by each spring The spring configuration is shown in Figure 5 Spring 1 Force Fs1 Ma Dfs1 144 6212 Spring 2 Force variable value units notes Distance of spring 2 attachment from point B L1 Ls2 sin ThetaS2 sin ThetaA L1 6 494353 Moment about B Mb 110 8456 Moment supplied by Spring 2 Ms2 Mb Spring 2 Force Ms2 Fs2 Dbfs2 Spring 2 Force Fs2 Ms2 Dbfs2 44 60082 Two locking gas springs were found shown in the materials list that are capable of supporting the appropriate amount of force The use of these springs makes this particular design viable 28 Budget Aluminum 6063 T52 Canvas Holder oquare aluminum tube 75 x 75 x 062 3 26 2 3 5 1 23 total 108 Aluminum Channel 2 x 1 x 125 2 75 total 1 5 Sheet metal 0625 thick 2 75 X 19
7. additional way to adjust the height of the canvas holder An Alan wrench can be used to loosen the bolts that attach the 180 degree pivot to the top of the easel extension Once the bolts are loosened on both sides the pivot can be moved higher or lower on the canvas holder to adjust the height Additional Canvas Holder Height Adjustments Adjusting Easel Height Once the desired height is achieved then an Alan wrench can again be used to retighten these bolts 44 Easel Extension To adjust the easel extension there are four 180 degree pivot brackets These are located at the point of attachment between the canvas holder and the easel extension and at the point of attachment between the easel extension and the base 180 Degree Pivot These can be adjusted by loosening the L handles one at a time then pivoting the canvas holder on the easel extension or pivoting the easel extension on the base vut ud d c wi e Easel Extension Attachment Attachment for the easel is controlled by screw fasteners located at the bottom of the base he base can be slid onto a wheel chair tray and locked into place by tightening the screw fasteners 45 Sliding Base onto Wheel Chair Tray This locks the easel base onto the wheel chair tray for use Securing Base to Wheelchair Tray 46 LED Light Use The LED light can be adjusted up and down via a friction hinge that attaches it to the Can
8. aluminum extrusions Aluminum is cost effective as well as lightweight and can mechanically provide the strength and support necessary for the design The bottom piece will be a 9 x 4 aluminum extrusion 23 inches in length and will act as the canvas sill to support the bottom of the canvas In order to increase the coefficient of friction on this piece a rubber strip will be adhered to the sill so that the canvas will not slide off as easily Perpendicular to this piece will be three aluminum extrusions to support the back of the canvas These pieces will be 26 inches in length and welded onto the sill extrusion At the top of these three pieces an extrusion will be welded in order to provide stability and so that the canvas clamp will not be able to slide off See Figure 3 for a detailed front view of the canvas holder A final aluminum extrusion will be used for the canvas clamp This extrusion will also be a 9 x 9 beam and will also have an adhered rubber strip to the surface in order to increase the coefficient of friction where the canvas will make contact The clamp shall be locked into position using 2 x 1 aluminum channels and wing nuts as shown in the top view of the clamping device in Figure 4 The pressure on the canvas by the clamp will stop the canvas from any movement thus locking it in place 16 Movable Canvas Clamp Rubber Strip i pepe l
9. be involved in the overall operation of the system The first was to support the first section of the arm This section had two parallel square aluminum tubes and was attached to the easel base by an eye joint The second section was pinned to the first and was articulated by a second locking gas spring Canvas Base After researching products that attach to a table top it was found most of these products made use of a C clamp Instead of using C clamps it was decided that making the base a C clamp itself would be the best way to attach it to a table top By constructing the base in a modified C shape it would allow it to slip over the edge of a table and lock down Ball Joint Pinned Joint Ball Joint Gas ra Spring 1 Eye Joint NN Ps U bracket Figure Side View of the Exension arm and Canvas holder N Locking Wingnut Joint Gas Spring 2 Eye Joint l U bracket Eye Joint U bracket 11 Figure 3 D view of Design 3 w o light 2 2 Optimal Design Team 3 chose to use components from design 2 and design 3 for the optimal design The lighting system from design 2 was selected because it was challenging and also feasible for construction because the cost of the easel was far below the total allotted budget for the project The canvas holder and clamp the extension arm and the base were taken from design 3 This particular canvas h
10. calculations were completed The bending stress found 19 4 MPa was much less than the 135 MPa need to yield the aluminum Note for the above calculations mechanical properties were taken from http ussautomotive com auto steelvsal mechproperties htm and http en wikipedia org wiki Tensile strength Because one locking mechanism can be used to support the weight of the easel and simulated canvas the second serves as an equalizer and secondary locking system This is so that if one clamp is undone the positioning assistant can make sure he or she has a firm grip on the easel before releasing the second clamp 62 Mechanical analysis of the base provided the force necessary to hold the easel in place and secure it to the table The diagram below shows the forces considered when calculating the moment about point D 0 620m d 0 590m mo 0 560m 0 229m MAR 0 363m 0 167M gt 0 110m NR S Point D LO Pa y e i 0 041m y g Z 0 114m lt D z 0 133m lt Y 0 207m Y Note The weights and forces denoted by W and F have Newton s as units of measurement 63 Wi N Ri b m Mi N m 13 91 3 89 1 48 1 85 4 45 1 85 5 22 6 31 0 74 5 20 2 28 4 64 13 34922 4 41 1 35 11 07 Totals about Point C Fc divided across 2 locking levers 124 3071 0 167 20 759
11. delay mode it is controlled by one external resistor and capacitor It offers the ability to adjust the oscillating duty cycle through the adjustment of resistor and capacitor values Coupled with the resistors and capacitors values chosen for this application it creates a square wave power source 32 B THRESHOLD qu 02 contaoL 9 23 Voc VOLTAGE 1 3 GND O O OUTPUT 2 TRIGGER C 4 RESET O 7 Poo AAA CENE WE DISCHARGE O pid GND Vec TRIGGER DISCHARGE OUTPUT THRESHOLD RESET VOLTAGE Connection Diagram for the LM555 www national com 33 TRIGGER CO gt R2 OUTPUT O Example of Square waves created with LM555 www national com The LM555 makes the LEDs operate off of an alternating square wave This mimics an AC source and saves battery life by having the LED s flash on and off at a very high frequency so it is not noticeable to the human eye This means the LEDs are only on half of the time therefore saving LED and battery life The operating voltage of the circuit is 9 6 volts There is a 3 6 volt drop across each LED Each transistor draws 1 mA of current during the on part of the square wave The potentiometer operates as the dimming switch by creating a larger voltage drop when the resistance is turned all of the Way up 34 Zoom of LM555 Chip in the Circuit Express PCB The potentiometer operates as the dimming switch by creating a larger voltage drop When the resistance is turned u
12. nearly adjustable enough Versa Table The Dreamer This product is motorized extremely adjustable and allows for large canvases However it has motors is very large expensive and offers no storage options ty ki a The Dreamer 7 Previous Project Design The Accessible Easel in Spring 2003 This product offered good adjustability sturdy frame and motorized adjustment However its adjustability was not specific enough exposed wires caused a problem and was not portable Accessible Easel 1 3 2 Patent Search Results Besides products that were available on the market it was important to also perform a patent search Upon searching the term adjustable easel with the United States Patent office seven items were found Most of the seven items did not overlap 5 with the Easel 5000 because they were devices that were not designed for a disabled person Many of the designs were for folding or collapsible easels There was one easel design that was specifically designed for a disabled person but made use of a crank instead of locking joints Included below are some of the patent numbers and short descriptions of the patents found Patent number Patent Name 6 045 108 Inclined adjustable easel with slidably drawer A multi purpose easel is provided for use by children artists and the like 5 074 513 Adjustable easel An easel adapted for use by disabled persons provides a frame for holdin
13. of the 49 locking mechanisms These mechanisms function by friction oiling these joints would remove this friction Case Specific Maintenance Components Failure If any of the mechanical components fail they can be replaced Ne some pat d Lia n tooling from a company called 80 20 Their web site is Also refer to the following directions In the event that one of the nylon disks at a locking handle needs to be replaced follow the instructions below Hemove the canvas holder by loosening the three hex screws on the side of each pivot joint c SN EN WSS EATE HERE AND ON THE OTHER SIDE FOR REPLACEMENT Completely remove the L handle by turning it in a counter clockwise direction until it comes off Set the L handle and any parts that do not need replacing aside A ASE RS AT MAY NEED TO BE REPLACED X p N E mm Replace the nylon disk s on the L handle assembly and reattach the L handle to the pivot joint The large nylon washer must be a 1 outer diameter 25 4mm washer If the entire L handle assembly breaks another can be ordered from AIR Inc in Framingham MA or another 80 20 distributor Part no 25 2796 After the part is replaced reattach the L handle assembly and fit the canvas holder onto the two pivot joint assemblies 51 Replacing the battery Note it should not be necessary to replace the battery for quite some time as it is rechargeable First unclip the battery from t
14. off How do fix it o This is usually caused by wear on the Velcro that happens over time Simply replace the Velcro stripping See the maintenance section for instructions on how to replace the Velcro e Problem LED lighting system doesn t turn on What s wrong o Because the lighting system does not turn on does not mean the system is broken Ifthe LED system is left on overnight or has not been recharged after prolonged use it is possible that the battery just needs recharging e To fix this simply plug the battery into the charger for 8 and 1 2 hours to bring the battery back up to full charge e Note The battery s runtime should be around 6 hours at full charge so if it is left on by accident overnight then the battery will be drained Ifthe battery is fully charged and the LED system still does not work check the LED enclosure to make sure that no water paint or other liquid has gotten into the box It is very important that the LED enclosure not be opened as a replacement of this particular device is not possible Ifthe LED box has been deluged with water paint or another substance or the circuitry has been disturbed in some way the damage to the PCB inside may be irreparable In this case another light may be purchased online or from a local store and mounted onto the easel o Do not open LED casing as paint water or other substance may damage circuitry inside and may cause the device to stop working o Do not ope
15. only be accomplished by Seth since he was the only member of the team that was machine shop certified For mechanical analysis purposes looking at stresses and determining forces applied throughout the easel design was completed This analysis was especially important to determine that the easel could function not only in ways that a normal easel could but also when the easel was adjusted in extreme positions unlike other easels The mechanical analyses completed were all documented and kept track of in excel format for computerized calculations When any design changes occurred this documentation was constantly updated Finally contributions to reports were made with various Microsoft Visio drawings 8 3 Justin Yu In the beginning of the semester Justin mostly helped out Seth at the machine shop to prepare all the pieces needed before easel construction began At this time the mechanical calculations were examined and rechecked since they were very important to ensure that the easel design could work When all the pieces arrived Justin was the main member in charge of easel construction Time management for the project was handled on a weekly basis to keep track of how far along the project each process needed to occur With the LED system after the PCB schematic was completed many designs had to be made In order to fit the LEDs in correct places and fit the PCB itself into the correct size encasement the PCB design was adjusted numerous time
16. piece will be a square 34 x 9 aluminum tube 23 inches in length and will act as the canvas sill to support the bottom of the canvas In order to increase the coefficient of friction on this piece a rubber strip was to be attached to the sill so that the canvas will not slide off as easily Perpendicular to this piece were three square 94 x SA aluminum tubes to support the back of the canvas These pieces were to be 26 inches in length and welded toward the middle of the sill An extrusion was welded to the top of these three pieces in order to provide stability and so that the canvas clamp would not be able to slide off Of those 3 vertical pieces the center aluminum tube would have a u bracket welded to the back so that it could join the extender arm Canvas Clamp An aluminum extrusion was used for the canvas clamp This extrusion was to be a 4 x 4 beam and would have had an adhered rubber strip attached to the surface in order to increase the coefficient of friction where the canvas will make contact The clamp was locked into position using 2 x 1 aluminum channels and wing nuts The 10 pressure on the canvas by the clamp was to stop the canvas from any movement thus locking it in place Easel Extension Arms Locking and moving the extension arm was accomplished with locking gas springs These were chosen because they were able to provide a system for easily adjusting and locking the easel in position Two gas springs were to
17. project was not just about making an end product it was also meant to be an introduction to industry experience While this experience can t be expected to exactly mimic an industry experience it was definately a good introduction As a team we learned how to develop organize and design a project This involved tons of calculation communication research and brainstorming By the end of the first semester we had gotten very good at this due to the fact we had to independently design four separate designs This was all done in the first semester and was a great experience but offered little hands on work Second semester offered a chance to really get experience putting something together As a team we had to achieve our individual goals and then integrate them for the combined project This took a lot of team work and communication As a team we had to learn how to respect each other s space and work We also had to learn how to lend a helping hand when needed Each member had a chance to learn something new during the project We all got experience crafting something and working with tools We all were also exposed to dealing with industry or suppliers through the acquisition of products that we manipulated for the project Also new programs were learned to help advance the project In all this project and course has offered up a great opportunity to broaden our experiences We have all experienced something new and had to deal with frustrations and p
18. reason team 3 considered a pine frame Lighting A method of lighting the canvas was required and could not be powered by a wall Socket because an electrical cord would have created a tripping hazard in the 6 environment where the easel was to be used A light emitting diode or LED was the best solution to all of the above requirements LED s were found to be low cost have an extremely long life were durable and emitted little heat Various other compact components would not only have been time consuming to construct but fairly expensive After some research it was found that a pre constructed LED system intended as a head lamp for camping was the best choice The price was reasonable at 69 95 and it was very compact Furthermore it would have saved time during the construction phase of the project Canvas Holder This part of the design supports the canvas from the back The backing was designed after traditional easels which utilize a single wide backing beam with a support lip at the bottom of the backing beam Since this design had two extension arms the easel mount had a frame that allowed the backing beam and lip to be attached The easel mount itself was to be tilted forward and back by a mechanism similar to that of a chalk board The range of canvas sizes to be supported was 8 x8 to 20 x20 Canvas Clamp To secure the canvas in place so that it did not fall on the artist when the easel was tilted forward a locking mecha
19. this trouble shooting section has been included to help the operator or assistant with common questions that may arise Please note that any repairs to the frame should be done by someone who has had some experience in metalworking woodworking and repairs to the battery should be done by an individual who has experience in electronics e Problem What if the canvas holder or extension arms move while the locking mechanisms are engaged o This can be hazardous for the user if the problem is not resolved quickly The canvas holder or the arms can move as a result of several situations If all the clamps are tightened sufficiently then checking the weight of the material mounted is the next step Overloading the canvas with too heavy a material may lead to the canvas holder readjusting without any assistance In this case the size of the canvas must be changed and a smaller painting surface must be used Please see the Safety Precautions section The most common problem may be forgetting to tighten one of the clamps as described above Ifthe problem persists check the L brakes and extension arm joints for damage to the nylon white washers If there is significant damage to the washers or one of the L brakes it should be replaced See the diagram below for the location of the washers and see the maintenance section for details NYLON DISKS LOCATED HERE AND DN THE OTHER SIDE FOR REPLACEMENT 56 e Problem The battery keeps falling
20. 06 1 31 2006 2 13 2006 2 13 2006 1 31 2006 2 14 2006 2 14 2006 2 16 2006 3 7 2006 3 20 2006 3 22 2006 3 27 2006 4 1 2006 LED Supply McMaster Carr McMaster Carr returns McMaster Car shipping on return Air Inc 80 20 Air Inc 80 20 returns Air Inc shipping on returns Modern Plastics Jameco Onlybatteris com Air Inc 80 20 Digi Key Air Inc 80 20 Mansfield Supply Air Inc 80 20 PCB Express 78 Total Spent Total Credit 1033 98 217 76 Total for Project with credit 816 22 Allowance made by Professor Enderle PCB 99 87 End Caps 25 Total Allowance 124 87 Total Allowance 691 35 Free Samples and Discounts Company Discount samples Onlybatteries com 20 off L EDtronics Free LED panel mounts Reell Incorporated Free Friction Positioning hinges OKWenclosures Free Plastic Enclosures Hammond Manufacturing Free Plastic Enclosures In conclusion with the NSF budget set at 750 the money spent on essential parts of the projected totaled 691 35 which is under budget If the PCB and end caps are factored in the budget reaches 816 22 While this is over budget these last second additions to the budget were allowed by Professor Enderle to finish the project correctly The budget allocated by the NSF was definitely substantial but if we had been more familiar with shipping and return costs the entire project could have been done for the NSF allocated budget 8 TEAM MEM
21. BER CONTRIBUTIONS 8 1 Alison Biercevicz The main part of the project that Alison worked on was the LED lighting system This required a large amount of work This included much research on LEDs timing chips circuitry batteries and production methods Many different designs had to be gone through in order to include the dimming option and prolonged battery life PCB schematic and PCB express were two programs that had to be learned in order to design and order a printed circuit board This also involved a trouble shooting A great deal of time was also spent keeping up with contacts and ordering to ensure the right parts were being ordered and free samples were being received In the last part of the 79 semester time was also spent in the machine shop helping Seth with final machining for the easel frame and LED enclosure The last two weeks involved extensive construction soldiering and trouble shooting with the PCB board In all a lot of basic skills for problem solving team work and communication were learned along with some very specific skills for dealing with machining PCBs and LEDs 8 2 Seth Novoson Seth s main job throughout the semester was machining the parts necessary to assemble the easel Although parts were easily attained and usable from 80 20 Corporation these parts still had to be cut down to size In addition holes needed to be drilled edges de burred extrusion ends thread tapped and various other tasks that could
22. EFERENCES National Science Foundation Find Funding http www nsf gov funding December 1 2005 The American Institute of Architects Architectural Graphic Standards for Residential Construction John Wiley and Sons 1999 U S Patent and Trademark Office Full Patent Data Base http www uspto gov patft index html December 1 2005 Abledata The Able Table http www abledata com abledata cfm pageid 1 135838top 08productid 10327 4 amp trail 0 December 1 2005 Solutions for Humans Versa Table Slantboard htip www storh com documeni versa table html December 1 2005 Extensions for Independence The Dreamer http www mouthstick net easel easel97 htm December 1 2005 The LED Supply Super Bright LEDs http www ledsupply com December 1 2005 Reell Incorporated Positioning Friction Hinge http www reell com downloads drawings reell phc pdf April 11 2006 National Semiconductor LM555 Timmer http cache national com ds LM LMS55 pdf April 11 2006 Hammond Manufacturing 599 Series box htip www hammondmig com pdi 1599E pdi April 11 2006 81 11 ACKNOWLEDGEMENTS In chronological order John Parmelee head of set design for UConn Joyce Frank Studio Coordinator for Passion Works Studios Patty Mitchell Art Director for Passion Works Studios Chris Liebler Teaching Assistant BME 290 291 Professor Robert Northrop BME professor UConn Kurt Jamlin Sales Representative for LEDtronics Nicki Sobcins
23. Final Report Easel 5000 By Alison Biercevicz Seth Novoson Justin Yu Team 3 Patty Mitchell Passion Works Studios 21 S Campbell Street Athens OH 45701 Phone 740 592 6659 ext 252 pattyO passionworks org TABLE OF CONTENTS S A ee me ee ee nee ere ere eee o e eea sakes donee ah cect ea dn 11 BACKOROUN oise da 1 2 J rpose or Pro e lunar idad 1 3 Previous Work Done by OtherS cccccoccccccccconcccccnnoconccnonancnnnnons 31 Marketed Produc Suar eoe tt Eee Deco oes 1 3 2 Patent Search Results eeeeesssseuus 1 4 Outline for Final Report 2 Proc Bloc ES 2 1 DESION AMONIO Sl Zu MB Io Pr 21 2 DESIL DVD DES Mc H 2 2 0ptmal DESIGN arista 22 O E e ced a eot tius 2 2 2 OUDU Tissue ins no Al r 0110 0 DO eee o Healisio Consta aca a 3 1 Engineeririg Standard Sarir indi s DO mieoisej er 3 9 ENVIO Melisa aida An td a tsen Nea ie 3 5 ManutacturaDllV ao a a aa A a 3 7 FICGILI and Sa n cte us SASE zie M DS POMA NE A Sae SS Saje ie a oe be be bil ea debi 5 Impact of Engineering SOlUIONS aec itor to pesos te mem to Peto sede pentes 8 1 JAIISOMDICKC zer O 2 OO e ocio add A A A 9 V GIOSING MOM AK one o ave e LOM ESENCO Sut TT 4AGKnOWIeddelelliSie ae o Eod oe ii TZ AD DENG cm a a S 12 1 Updated SpEciNCal ONS uocare O 0 0 0 O 01 YO O N NN P ABSTRACT Easel 5000 is a project aimed at designing an adjustable art easel for an artist having
24. The table labled Moment about Point D shows the calculated forces and moments for the diagram above as well as the force necessary to stabilize the easel on the table This force is labeled Ft tress on the screws Variable Value Units Value MPa 4 40E 06 Pa 1 24E 02N 2 83E 05 m 2 Assumed Structural Steel for yield point lowest of steels 4 00E 08 Pa To ensure that the threaded rods bought would be able to function in the role intended the value of stress was determined The stress put on the screws 3 30 MPa was far less thant the yielding stress of the screw s material 400 MPa The mechanical analysis showed that the easel would function under normal operating parameters and the secondary locking system and the easel clamping system would work as well PROTOTYPE TESTING Whenever a prototype is made testing is an essential part of the construction process While the Easel 5000 was being constructed testing was constantly being 64 done in order to trouble shoot Testing during construction helped to bring up many problems During one of the first tests there was a problem with the canvas holder stability The canvas holder was found to oscillate when hit and create a painting surface that shook Ideas were discussed to solve this and the appropriate parts were bought and the problem was fixed This was done by eliminating some of the length of the easel extension and adding an extra arm thus overall simplifying the de
25. a diagram of the forces used in calculating the stresses placed on the easel as well as a table with the mechanical stress analysis results The forces created by the weight of the easel created a moment of 13 52 N m about the set of hinges attached to the base And the appropriate force required to hold up the easel could be supplied by the locking levers Weight Calculations The weights of each individual section were obtained by measuring the unit length in meters and then plugging into the following equations For lengths of 25 2525 weight Length mass meter gravity Length is in meters Mass Is in kilograms gravity is in meters sec 2 W L Mc g W L 7443 9 81 For lengths of 25 2527 W L 6538 9 81 For lengths of 25 2550 W L 1 3052 9 81 58 The table below shows the results of the weight calculations These results were used in the computation of the bending stresses and normal stresses in respective selected aluminum extrusion lengths and screws that were needed to hold the easel in place Section Total Weight N Number of pieces Indiv Weight N k 3 1 1 2 2 2 2 4 4 2 1 4 1 1 2 1 total weight 52 80 total weight 11 87 59 0 731m 0 701m Point C 0 151m 0 225m 0 244m The diagram above was used to calculate the moment about the first set of dynamic piv
26. asted roughly six hours at its highest setting It also took eight hours to charge to its full capacity Finally the LED system was checked to make sure the dimming knob as well as the on off switch were fully functional In conclusion testing was an essential part of the prototype building process This allowed us to trouble shoot and solve problems with the easel Also it allowed us to find the constraints on its use These things are all very critical to the easel s use 3 REALISTIC CONSTRAINTS 3 1 Engineering Standards When designing and constructing any prototype it is important to take engineering standards into consideration Engineering standards vary by application but in general they apply to the technical structural and quality standards of a product These standards are important and make sure the product is safe for use These standards were very important when designing and constructing the prototype for the Easel 5000 When designing the Easel 5000 it was important to take into account technical structural and overall finished quality We wanted to make sure that technically the easel fulfilled its specifications set out for the project last semester Things like adjustability locking joints canvas weight and a light source were all things that had to be considered Structurally the easel had to be sound It had to support a canvas of vary weights sizes and materials Also it had to with stand regular use and be easy to use Wh
27. bber stripping may wear out and it may become necessary to replace the stripping on the easel to table clamps To do this follow the directions below Remove the worn rubber stripping be sure to attempt to remove as much of the remaining glue residue as possible Cut new rubber stripping from a large piece of rubber to 21 x 3 8 This may require cutting out more than one strip of rubber depending upon how many rubber strips need to be replaced Fit the rubber stripping on to the canvas clamp or canvas holder Rubber stripping that has an adhesive surface is the easiest material to use as a replacement solution Replacing Velcro stripping on the White battery box Due to repeated removal of the battery enclosure from the easel the Velcro may weaken over time Eventually it may become necessary to replace the Velcro to ensure that the battery enclosure remains attached to the easel Remove the battery enclosure from the easel and unhook the battery Gently remove the battery from the enclosure Using a knife or other cutting tool carefully remove each of the three Velcro strips from the battery box 55 LED light Failing If the entire LED light fails it can be replaced by a store bought light This is the suggested means of replacement Otherwise the technical description can be referenced for further ideas on how to fix it TROUBLE SHOOTING Although Team Easel 5000 hopes that the use of the easel will be seamless
28. components may be brought to the nearest recycling center for future use The other steel components may be recycled as well and the other smaller components should be disposed of 3 4 Sustainability Maintenance for the Easel 5000 will be minimal Although aluminum is very corrosion resistant the easel will be painted thus further reducing possible corrosion With moderate use the easel maintenance could consist of oiling joints to reduce friction and squeaking Bolts may need tightening on occasion and rubber strips may need adhesive reapplied Repairs to the easel may be made by replacing any damaged parts The easel will include an operating manual addressing these parts This manual will be included in the packing contents An approximate estimate for the lifetime of the easel will be five years in which the device might fail due to fatigue and general wear However the non metal components of the design will likely need to be replaced before five years of use These parts include LED lights wires batteries bolts washers and paint 3 5 Manufacturability Easel 5000 will be manufactured on the University of Connecticut campus in the certified machine shop Aluminum is an easily machined material and thus was highly considered as the usable metal for easel components The optimal design includes dimensions and details on each subunit within the easel to make effective future reproductions of the Easel 5000 3 6 Ethical No animals o
29. d Current Max Forward Current Pulse Forward Voltage Max Reverse Voltage Power Dissipation Operating Temp Soldering Temp Max Reverse Current side View Value L1 0 W5TH15 1 15 5mm 18000mcd typ Y 20mA 30mA 100mA for 2 10ms duty 1 10 3 6V typ 4 0V max 20mA 5V 120mW 30 to 85 C 265 C for 10 secs 50UA 5V LED Polarity Top View LED Schematic The above circuit shows two branches of the eight branches of the LED circuit This shows the combination of LEDs in parallel and series This combination of two in series and eight branches in parallel for a total of 16 LEDs let the circuit operate to maximum capacity This let the most LEDs run on the smallest power supply the appropriate amount of current to each of the LEDs allowing them to burn at maximum capacity The NPN switching transistor at the end of each branch is to ensure that the appropriate amount of current is always being provided and the maximum capacity of the LEDs is not surpassed This is due to the oscillating square wave provided by the LM555 that this problem can arise Circuit The following is the circuit diagram for the LED light of the product It includes resistances LEDs a power source transistors capacitors an LM555 chip and a potentiometer There are important features and characteristics of the diagram to note The LM555 chip is a highly stable device for generating accurate time delays or oscillation When configured in time
30. ding rails See mechanical analysis section for equations and data breakdown l LAS nu Figure 7 Base frame made of architectural angle U brackets for extension arm attachment Paint brush ledge Lip for slide out shel Figure 8 Completed easel base 20 brackets for extenstion arm Xx Ma A Y ae Sliding Shel SE screw fasteners Figure 9 Side view of easel base Figure 10 Conceptual drawing of Easel5000 MECHANICAL ANALYSIS Weight Calculations for Aluminum Pieces Quantity of dimensions Kind of piece piece nave in3 e angle u 1 Base 5 X 5 X 0625 frame Mp 468 area in2 frame 5 616 dium 1 u4l 4 A paintbrushledge 1 te o y 0702 IV LEE 4 9894 us Quantity of piece width in length in thicknessin metal iopandbotomcover e re as oa tw metal top and bottom cover 12 0 0625 4 za 0065 6 daj o 0025 9 weight Al V of sheet Ibs in3 sheet metal sa 009 Total volume of the base weight 63 594 5 72346 no Kind of piece i i volume in3 piece Quantity of dimensions piece Quantity of qu ens Kind of piece Diece volume in3 2 Aluminum channel square tube Volume of Entire needed needed in sheet metal Easel 108 95 1268125 Weight of Entire Easel 8 561413125 Base Mechanical Analysis hla A Fe L E Fd VED F
31. e design and construction of the easel must cost less than 750 The easel design can be broken down into five major components The components are the light source the adjustable easel mount the canvas holder the easel extension and the base 13 2 2 2 Subunits LIGHT SOURCE The light source for the Easel 5000 must be battery operated to reduce any tripping hazard that could result from a power cord It must be lightweight and compact yet provide sufficient light to illuminate the canvas surface An easy on off switch is also desired for ease of use Also it would be beneficial if the light source was energy efficient and required minimal battery changes A light emitting diode or LED is the best solution to all of the above requirements LED s are low cost have an extremely long life are durable and emit little heat A panel mount string LED system will be used at the top of the canvas holder to illuminate the canvas The LED string will be mounted inside an aluminum architectural angle bar The bar will then be attached to the top of the canvas holder with a piano hinge to allow for the positioning of the light source The LEDs being used will be super bright LEDs that are capable of emitting 18 candela of light operating with a current of 20 milliamps 18 to 20 candelas are recommended for illuminating an object for viewing purposes Six of these LEDs will be set up in a circuit with resistors a 9 volt battery power supply a
32. e tone abnormal muscle movements and vision problems The ultimate goal of the project is to build an art easel that will allow Tom to paint from his wheel chair 1 2 Purpose of Project Because cerebral palsy affects one s strength dexterity and range of motion the easel will be built to compensate the artist in these areas Previously an adjustable easel was designed in 2003 but did not completely fulfill the needs of the artist The first design did not have the adjustability needed by Tom It also had a motor that was difficult to use and was a t hazard because of the motors exposed electrical cords The ultimate goal of the current project Easel 5000 is to create a new design better suited to meet the needs of the artist and address the design flaws of the first easel The artist is in need of an easel that can be easily adjusted Since the artist has a limited range of motion painting with a single position easel is incredibly difficult The artist also cannot use a standard easel with tripod legs due to the fact that he is in a wheelchair The easel would need to account for wheelchair dimensions in order for the artist to use it appropriately In addition the artist is unable to paint unless the canvas projects out close to his wheel chair Artist Tom Depugh With this project we aim to use educational knowledge and background to design an easel that meets the specifications presented by the National Science Foundation T
33. extended period of time 74 Before turning the LED system on be sure that the LEDs are not pointed at the face of the user or any bystander The third factor accounted for in the safety manual was that concerning electrical hazards Although all the wiring power source and circuitry are enclosed and insulated there are certain conditions of operation that would prevent the user from getting injured e t was thought that a general warning was important and so that was included in the manual o WARNING Product CONTAINS ELECTRICAL COMPONENTS Other situations that may arise were thought of and appropriate warnings were created to give the operator guidance when using the easel e Shock hazard o Recommendations to avoid being shocked by the battery Keep LED light enclosure closed at all times DO NOT OPEN THE LED LIGHT UNDER ANY CIRCUMSTANCES Keep water away from the LED light Keep paint and other painting supplies away from the LED light Keep water away from the battery compartment Keep paint and other painting supplies away from battery compartment e Similarly to keep the battery from shorting at the connectors the following guidelines and warnings were put in place o Recommendations to prevent shock and shorting due to battery connector and lead problems Keep water away from the battery connectors Keep paint and other painting supplies away from the battery connection When recharging battery first connec
34. g a canvas which can be tilted by means of a crank D249 533 Foldable portfolio with an adjustable easel The ornamental design for a foldable portfolio with an adjustable easel 1 4 Outline for Final Report The remainder of this report will discuss the stages of design and other considerations of the project The stages of design include alternative designs the optimal design and then prototype building Other considerations for the project include realistic constraints such as engineering standards and manufacturability Safety and impact as well as life long learning will also be discussed The budget and parts break down will be included to see if the 750 dollar mark was met Finally the report will wrap up with a conclusion references and acknowledgements 2 PROJECT DESIGN 2 1 Design Alternatives During the development of our project three potential designs were created to address the needs of the client These three designs were all significantly different in the way they accomplished all of the previously mentioned criteria see Objectives section defined by our client Dr Brooke Hallowell In addition a draw for art supplies was added to the design and integrated into the mechanism that attached the easel to the table 2 1 2 Design 1 Materials Traditionally easels have been made of wood Wood also provides a much warmer tone than metal and is generally more aesthetically pleasing in an art and creative setting For this
35. g the easel The following is a list of items generated to account for the mechanical safety of the artist and assistant 72 e Pinching hazard at dynamic pivot joints o Warnings included in the manual WARNING Pinching hazard at joints o Recommendations for avoiding the situation described Be sure that fingers are clear of any moving joint before adjusting the easel Only after fingers are clear of joints should one adjust the easel There is also a list of joints in safety manual where there is a pinching hazard e The four 180 degree pivots e he L brakes on the canvas holder e Adjustable friction positioning hinge for the LED light e Base fasteners e Canvas Holder section may fall on the user o Warnings included in the manual WARNING Canvas holder may fall on user o Recommendations for avoiding the situation described Be sure to tightened both locking handles at one joint before letting go of the easel after adjustments have been made Only loosen one L brake at a time Only let go of the easel after both sets of L brakes have been tightened securely Make sure both L brakes are tightened securely after adjustment is finished When adjusting the canvas holder make sure to adjust one L brake at a time to avoid loosing control of the easel e Canvas or other painting surface may fall out of the canvas holder o Warnings included in the manual WARNING Canvas may fall on user o Recommendations for avoiding the s
36. he wires connecting it to the LED system The correct clips can be found at the base of the easel Take the white battery enclosure off the easel 22 Remove the top of the white enclosure Grasp the battery and pull the battery out REMOVE BATTERY 53 Insert new 9 6V 1700mAh battery into the white casing REPLACE BATTERY Replace cap and put the enclosure back onto the Easel REPLACE BATTERY ME 54 Replacing the battery wiring after accidental wire severing Warning Rewiring a battery should only be done by a professional because of a significant shock hazard Discharge the battery before attempting to replace the wire If there is no one with experience to do the repair do not attempt to repair the battery wire Replacing the rubber stripping Over time the rubber stripping may wear out and it may become necessary to replace the stripping on the canvas clamp and or the canvas holder To do this follow the directions below Remove the worn rubber stripping be sure to attempt to remove as much of the remaining glue residue as possible Cut new rubber stripping from a large piece of rubber to 21 x 3 8 This may require cutting out more than one strip of rubber depending upon how many rubber strips need to be replaced Fit the rubber stripping on to the canvas clamp or canvas holder Replacing the rubber stripping on the easel to table clamping device Over time the ru
37. hese specifications fall into four main categories environmental electrical mechanical and economical The environment the easel will be used in will require it to portable wheel chair tray size and easily used in a busy art room setting The electrical requirements will include a cordless light source with an easy on off switch Mechanically the easel will need stability flexible locking joints and be able to accommodate a 20 X 20 canvas Economically the design and construction of the easel must cost less than 750 The project is also meant to be an introduction to industry experience Learning how to develop organize and design a project as well as team work are all important aspects of the project 1 3 Previous Work Done by Others 1 3 1 Marketed Products There are many products out in the market with similar designs as the Easel 5000 These products range in price drastically and have varying degrees of adjustability as well as quality Three specific products shall be discussed all of which were found on AbleData com Able Table a product by Weir Enterprises This product offers an affordable light weight and fairly flexible option However this product does not adjust to the exact position needed for this project Also the product description states it is fragile if handed roughly Able Table Versa Table A product by KayJae This product is also an affordable lightweight option that offers easy storage However it is not
38. igure 11 Free body diagram for the base hla Fe A WE F c BEEN lI E 1 ra Figure 12 Simplified free body diagram Definition of Variables Ma Moment about A caused by the weight of the extension arms 117 143 Ib in Fd The force exerted on the front of the base Wb The weight of the base Fe The force exerted on the underside of the table lb Moment of inertia of architectural angle After doing a moment and force analysis on the base it was found that the force exerted on the bottom of the table Fe is a small and reasonable value It was also observed that the bending stress on the frame would not exceed the bending stress of aluminum Bending stress for Aluminum architectural angel at point E og Ma Cy lb P c E cf x r Figure 13 Reference for ly calculation lb Cy 2 2 1 3 3 Lc wd TETE 3 ta a y a t la y t 2 2a t 1 16 0625 a 5 Cy 148 y a Cy y 392 lb 001348 in op Ma Cy lp 12 861 psi Low End Yield strength for Aluminum 16 000 psi Bending stress of aluminum at point E og Ma Cy lp Yield strength for Aluminum 12 861 psi 16 000 psi Design is effective 24 Determination of the Force on the Table Fe gt F 0 Fe Wg Fp 1 2 MA 0 Ma 4Fe 6Fp 2 Using 2 to solve for Fe Ma 4Fe 6Fp 4Fg Ma z 6Fp 4Fe 6Fp T MA FE 1 5Fp Y4M a 3 Substituting 3 into 1 O 1 5Fo Ma We Fp
39. ile making the easel functional was the main goal of the project aesthetics also had to be considered The easel had to look professional and finished Machining and tooling had to be done carefully in order to ensure clean lines on the product and a finished look Also much forethought had to be put into many of the components to make sure the final product didn t have any visible mistakes Taking engineering standards into consideration really took the project from simply functional to complete and professional 70 3 2 Economic As mentioned the funding allotted for the project is a maximum of 750 This budget will need to cover all aspects of the easel Examples of necessary budget expenditures are raw materials machine shop welding troubleshooting and packaging Overall the finished product of the Easel 5000 will strive to be affordable to the public With efficient design the easel will have a lower cost than many commercial products to date with similar or competitive features 3 3 Environmental The finished product of the Easel 5000 will be composed of nontoxic materials The only materials used for the easel will be aluminum rubber plastic and steel The process of designing and constructing the easel will be environmentally safe The majority of the easel is constructed of aluminum That being the case the project can be easily disposed of in an environmentally friendly manner By removing the non aluminum pieces the aluminum
40. ill depress the button controlling the spring while simultaneously holding the arm to be adjusted Because of the light weight of the arm repositioning the device will be extremely easy Piston Transparent Pressure tube Connecting Rod End Cap Cap Adjustment Valve Figure 6 Gas springs to be used to lock the extension arms in place EASEL BASE The base of the easel needs to support the rest of the easel and attach to a tabletop After researching products that attach to a table top it was found most of these products made use of a C clamp Instead of using C clamps it was decided that making the base a C clamp itself would be the best way to attach it to a table top By constructing the base in a modified C shape it would allow it to slip over the edge of a table and lock down Most products on the market that are made for table top attachment accommodate a table that is between 2 and 2 12 thick The base will be made to accommodate tables that are up to 3 thick Hand retractable spring plungers will be used along with locknuts mounted to the inside of the frame for locking the base to the table The base will be a framework of 12 x V x 4g aluminum architectural angle covered with 1 16 thick aluminum sheet metal The base will include a paint brush 19 ledge and a small slide out shelf for paint brush cleaning The shelf will be attached to the bottom of the base with sli
41. is craft Unfortunately passion works had difficulty supplying Tom with a device for painting that was sensitive enough to his needs Team three has been given the chance to design and construct an easel specifically for Tom Now Tom will have a means to paint and do what makes him happy more easily When discussing the project with Patty Mitchell the Passion Works art coordinator it became obvious how important this easel would be for Tom She discussed how close her relationship with Tom was and how much she wanted an easel that would make painting easier for him After discussing our project with her further she gave us a better idea of where the design and construction should head All of the input from Patty was put to good use when putting together the easel Patty was emailed pictures of the final product and she was ecstatic She seemed hopeful that our project would be the right fit for Tom This easel will really make a difference in Tom s life Because Passion works is a globally reaching program Tom s new found ability to paint will reach many people His paintings have previously been shown and sold in galleries for increasingly high fees The Easel 5000 will make this reality much easier Tom s income from his paintings will help further himself and his program economically hopefully reaching out to other people with similar artistic passion 76 nodi aian kare uda Big Headed Girl by Artist Tom VUL 6 LIFE LONG LEARNING The
42. ituation described Check to make sure that the canvas clamp rubber stripping contacts as much of the canvas frame as possible Check that the canvas clamp is securely fastened and that the canvas clamp locking handles have been tightened Do not overload canvas holder Do not place materials larger than 9 X36 or 20 X24 into the easel frame Do not attempt to adjust the canvas clamping mechanism while the canvas holder is over the artist Do not attempt to adjust the canvas clamping mechanism while the canvas holder is inclined forward Make sure to retract the easel extension before adjusting canvas clamp Use slots in the canvas holder when ever possible when mounting a canvas Avoid Canvas weights in excess of ten pounds 73 Make sure that both sets of locking mechanisms engage for canvas loads of over 3 pounds e Easel may slide off the table or become dislodged o Warnings included in the user s manual WARNING Do not use the easel if the base is not securely fastened to the surface it is mounted on e Failure to secure the base to the surface it is mounted on can result in the easel falling on the artist Make sure both fasteners on the base are secured to its mounting surface before use e Velcro wear may cause battery to fall off easel and onto user o Warnings included in the user s manual WARNING Abuse of Velcro on Battery compartment can cause loosening of battery o Recommendations Avoid abuse of battery co
43. ively and under budget Easel Extension 9 LJ Canvas Holder Easel Base Figure Side view of the optimal design 2 2 1 Objective Project Easel 5000 is a cooperative effort between UConn s Biomedical Engineering Senior design class and the National Science Foundation or the NSF The specific project being worked on for the NSF is called Engineering Projects to Aid Persons with Disabilities The objective of project Easel 5000 is to build a new adjustable easel for an artist with cerebral palsy Previously an adjustable easel was designed in 2003 However it did not completely fulfill the needs of the artist The first design did not have the adjustability needed It also had a motor that the artist had difficulty using and was a tripping hazard because of the motor s electric cord at the location where it was used The objectives of the project are to build a new adjustable easel that meets the specifications presented by the NSF These specifications fall into four main categories environmental electrical mechanical and economical The environment the easel will be used in will require it to portable table top size and easily used in a busy art room setting The electrical requirements will include a cordless light source with an easy on off switch Mechanically the easel will need stability flexible locking joints and be able to accommodate a 20 x 20 canvas Economically th
44. ki Sales Representative for Reell Incorporated Jeff Dutches Sales Representative for OKW Enclosures Hammond Manufacturing Paul Dufilie ECE department Brooke Hallowell Professor John Enderle BME Department Head 12 APPENDIX 12 1 Updated Specifications Introduction and Overview Through the National Science Foundation the Biomedical Engineering Senior Design has been given the opportunity to build an adjustable easel that will be used in an art studio specifically for an artist with cerebral palsy The easel project has been done previously but was not appropriate for the artist hence Team 3 will be designing and building an easel suited for his use The easel itself will have the ability to tilt forward and backward be brought toward the artist have a lighting system and attach and detach from a wheelchair tray Ultimately this easel will be used in the Passion Works Studio and will hopefully be very helpful for the artist Technical Specifications Environmental Space and Dimensional Considerations oize Ability to be fastened on a wheelchair tray Weight Light enough to be moved by an aid Location Used in the middle of a busy art room Electrical Lighting Power Supply Cordless Battery operated Illumination Able to illuminate a canvas On Off Switch Easily operated Mechanical Structural Considerations 82 Stability Moveable Joints Lockable Positions Canvas size Economical Budget Maximum Sturdy when attached to
45. m N i nA in Pi Pu B LA Cw x LJ WI DJ p CN i O O M gU k o i NN pI ML MI 2 MI ah Friction Hinge Side and Front View Reell com Plastic Enclosure This prefabricated plastic enclosure by Hammond Manufacturing offered a perfect option for housing the LED lighting unit The enclosure is made of flame retardant UL94 plastic and has brass inserts in the corners for securing the box closed It was a good size offered easy mounting and was easy to machine for the features of the LED circuit board Top View of LED Enclosure Hammondmtg com 37 PE Side View of LED Enclosure Hammondmfg com Easel Frame The Easel 5000 consists of four main parts constructed from 80 20 extrusion and the LED system which was constructed separately Each of the four mechanical sections is composed of either 25 2525 25 2550 or 25 2527 extrusion Easel Base The base was designed specifically to fit the smaller table that attaches to a wheel chair The particular mechanism for securing the easel to the table is embedded in the base in the form of a C clamp style locking clamp The two knobs turn and drive the flat metal plates upward The metal plates are covered with rubber to avoid scoring the table and to increase friction between the plates and the table These locking knobs tighten sufficiently to secure the easel so that it may be used 1 5 38 1 mm was taken as the table depth and the metal plates used are approxi
46. mately 3 8 inch in depth leaving a clearance of 1 8 inch to fit the base on to the table 0 22 Easel Base ns Tray K AD E Ke Q zT O z lt E o z E a gt I E m Z d ru z E U S O C i L ke in Attach 39 Easel Extension Arms The extension arms were originally designed as a single arm with three joint articulations instead of two Because of design requirement changes from the first semester stability reasons and cost constraints the design was changed to a 2 arm design with two articulations The range of motion that the Easel 5000 has is large enough so that the easel can be used and has been tested N PREVIDUSLY ASSEMBLED EASEL BASE In the diagram above the parts labeled D are the easel arms Each of the extension arm beams are made of 25 2525 80 20 extrusion that are each 12 304 8mm long At the base are 2 dynamic locking pivot joints which are bolted onto two 5 127mm lengths of 25 2525 40 Adjusting the Canvas Position Using Pivots On Extension Arms The Canvas holder was designed to accept up to a 20 X24 canvas art surface This section of the easel also includes rubber stripping and when the canvas clamp is Canvas Holder used in conjuction with the canvas holder the painting surface can be inclined so that the artist can paint at an upward angle X WRENCH CO 5 E O dl Y a dr ca mei sei Adju
47. motor function disorders that affect strength dexterity and range of motion The needs of the artist require the easel to be easily adjustable have a large range of motion with locking positions and have the ability to integrate with a pre existing wheel chair tray Additional features of the project include an LED lighting unit with adjustable light intensity and a canvas holder that accommodates a large range of canvases 1 INTRODUCTION 1 1 Background Project Easel 5000 is a cooperative effort between UConn s Biomedical Engineering Senior design class and the National Science foundation The specific project being worked on for the National Science foundation is Engineering Projects to Aid Persons with Disabilities The mission of this program is to create devices that assist individuals in reaching their maximum potential for enjoyable and productive lives Dr Brooke Hallowell will be the National Science Foundation representative consulting on project Easel 5000 The project is being done for an artist at Passion Works Studios Passion Works is a unique program that creates art opportunities for people with developmental disabilities Patty Mitchell the art director at Passion Works studios was the main contact for the project Tom Depugh is the artist the project is being completed for and his disability is cerebral palsy Cerebral palsy is a condition that results from brain damage The symptoms include loss of fine motor ability abnormal muscl
48. mpartment and Velcro Replace Velcro when Battery compartment appears to be unstably attached These safety recommendations were effected so that the user and adjuster could operate the easel without risk of injury from mechanical actuation of the easel if the guidelines are followed The second set of factors was environmental concerns While the easel is made of aluminum which is a rather robust material for the application certain environmental factors encountered during use could put the user and easel in jeopardy To account for environmental hazards the following items were considered e Alarge external force may be applied to the easel o Warnings included in the user s manual WARNING DO NOT PLACE EXCESSIVE FORCE ON THE EASEL o Recommendations Do not use the easel for holding objects other than art paper and canvases The easel may be used to hold sheets of metal within the specified weight range of 3 10 lbs DO NOT USE THE EASEL TO SUPPORT A PERSON S WEIGHT DO NOT HANG OR LEAN ON THE EASEL e Looking directly into the LEDs may cause temporary disorientation and pain o Warnings included in the user s manual WARNING DO NOT LOOK DIRECTLY AT THE LED LIGHT Looking directly at the LED light for an extended period of time can cause damage to the eyes o Recommended use guidelines to avoid situation If adjusting the LED light dim it or turn it off first Do not intentionally shine the LED system in the eyes for an
49. n the LED casing while the device is on e Problem The canvas is sliding off the easel when the canvas holder is inclined o Usually the canvas clamp is not securely in place and as a result the frictional forces usually provided by the rubber stripping is not great enough to hold the canvas in place To resolve this issue tighten the canvas clamp onto the frame of the canvas or other art surface Make sure that the rubber stripping contacts as much of the edge of the canvas frame as possible o Another possible cause is that the material mounted in the canvas clamp is too heavy n this case the canvas being used should be downsized Do not overload the canvas holder Do not place materials larger than 9 X36 or 20 X24 into the easel frame Do not attempt to adjust the canvas clamping mechanism while the canvas holder is over the artist o The last possibility and most unlikely is that the glue attaching the rubber stripping to the canvas holder or canvas clamp could be worn To fix this problem two options are available 24 e Glue the existing rubber stripping back on e Buy and cut new rubber stripping as described in the maintenance section Either option should restore easel functionality Mechanical Analysis Although it was believed that the aluminum extrusion would have no problem supporting the weight of the easel and canvas frame mechanical analysis was done to verify intuitive suspicions Below is
50. nd an on off switch They will be arranged in a string in order to illuminate across the entire surface of the canvas Figure 1 Light mount 14 Spec Value Product ID L1 0 W5TH15 1 Angle 15 Package 5mm Color Peak Wavelength in nm Luminous Intensity 18000mcd typ Y 20mA Max Forward Current 30mA Max Forward Current Pulse 100mA for lt 10ms duty lt 1 10 Forward Voltage 3 6V typ 4 0V max 20mA Max Reverse Voltage 5V Power Dissipation 120mW Operating Temp 30 to 85 C Soldering Temp 265 C for 10 secs Max Reverse Current 50uA O 5V 9V J 3 6V Each Resistor 90 ohms Figure 2 Circuit for LED system 15 LED SYSTEM ANALYSIS AND CALCULATIONS Each LED has a 3 6 voltage drop Each LED requires 20 milliamps to operate at 18 candela For one branch of the circuit 3 6V 3 6V 7 2V Kirchoff s Voltage loop Voltage across the resistor 9V 7 2V 1 8V Current across the resistor 02A Ohm s Law R V I R 1 8V 02A 90 ohms To ensure there is not too much wattage lost in the resistor Watts I V 02A 1 8V 036 W CANVAS HOLDER The canvas holder will be the portion of the easel that holds the canvas onto the easel The canvas holder used in this design is very similar to basic easel designs The easel will hold the canvas and will be the support for the painting It is to be designed to be capable of holding canvas sizes up to 20 x 20 The canvas holder will be produced out of 9 x 34
51. ng purposes Six of these LEDs will be set up in a circuit with resistors a 9 volt battery power supply and an on off switch They will be arranged in a string in order to illuminate across the entire surface of the canvas Canvas Holder The bottom piece will be a square 34 x 9 aluminum tube 23 inches in length and will act as the canvas sill to support the bottom of the canvas In order to increase the coefficient of friction on this piece a rubber strip was to be attached to the sill so that the canvas will not slide off as easily Perpendicular to this piece were three square 34 x SA aluminum tubes to support the back of the canvas These pieces were to be 26 inches in length and welded toward the middle of the sill An extrusion was welded to the top of these three pieces in order to provide stability and so that the canvas clamp would not be able to slide off Canvas Clamp An aluminum extrusion was used for the canvas clamp This extrusion was to be a 4 x 34 beam and would have had an adhered rubber strip attached to the surface in order to increase the coefficient of friction where the canvas will make contact The clamp was locked into position using 2 x 1 aluminum channels and wing nuts The pressure on the canvas by the clamp was to stop the canvas from any movement thus locking it in place Easel Extension Arms A roller mechanism was used to extend the canvas holder A roller cage mounted to the easel base was to have a s
52. nism was needed This mechanism took the form of a canvas clamp The clamp was a block that was secured to the backing beam by a screw that locked into a metal track When tightened this screw would have make contact with the metal track tightening a rectangular nut set in the track The pressure here will stop the canvas from any movement thus lock the canvas clamp in place and secure the actual canvas to the easel Easel Extension Arms This is the part of the design that made the easel Agjustable The system was symmetrical with two arm extensions on either side On each side the arm section attached to the base was 30 inches in length and was joined to the base with a hinge and was locked in place by a drafting board support device The second arm section extension was attached with a bolt to the first arm section and secured in place by a sliding rail and screw Once the easel had been positioned into place the screw was tightened thus locking the second arm section Figure 3 D conceptual drawing of Design 1 2 1 2 Design 2 Materials Team 3 decided to use metal for the second design It had better mechanical properties than wood and the team had received input that wood projects had turned out poorly in the past Lighting The LEDs being used will be super bright LEDs that are capable of emitting 18 candela of light operating with a current of 20 milliamps 18 to 20 candelas are recommended for illuminating an object for viewi
53. nt g Ball N Joint Locking O Wingnut Joint Gas A Gas Spring 2 Spring 1 Eye Joint U bracket Eye Joint Eye Joint U bracket U bracket Figure 5 Side view of the easel extender arm and the easel canvas mount While the joints allow an incredible amount of flexibility because they are only pinned another mechanism is required to lock the joint in place In the search for ways to secure the joints the muscular system of the body was used for comparison The arms legs fingers and toes are all capable of the type of motion that the easel needs to replicate These limbs are capable of locking in place and holding up significant amounts of weight From this inspiration research was conducted for methods of securing joins by using mechanical linear actuators However the easel is not able to use power from a wall socket using an electrically powered linear actuator is impractical because powering the actuator with battery power would require too large a battery Gas springs are similar to electrically powered linear actuators in the fact that they provide linear resistive force The gas spring operates by a control valve that allows an inert gas such as nitrogen to pass freely between two chambers Closing the 18 valve stops the flow of gas from one chamber to the other and effectively locks the spring in place These locking gas springs will hold the extender arm in place When the arm is to be readjusted the user w
54. older was selected for the simplicity of construction strength of materials and overall support provided to the canvas itself The rubber attached to the lip of the canvas holder was also considered to be advantageous when locking the canvas in place The clamping mechanism was also quite simple in operation and would lock the canvas in place sufficiently due to the rubber stripping designed into the canvas clamp and metallic construction The gas spring aided locking articulation from design 3 was selected because it provided an easy way of adjusting the easel extension arm locking it into place and used a ball joint It was also selected because releasing the adjustment should allow for gradual repositioning as opposed to the abrupt release of the screw locking mechanism present in the other two designs The base is also relatively simple in construction and locking concept It also provides some weight to the device so when the extension arm is locked in position it will stay locked into position and fastened to the table securely 12 The optimal design incorporates what team 3 believes to be the best assets of the three designs into one design The design has no electrical cords is lighted is easily adjustable and can be transported from one spot to another with relative ease Because of the metal construction the easel should be durable enough for everyday use Overall this design fulfills the objectives of the project simply effect
55. ot joints at point C For the ease of calculations the two pivots were taken as one and the two easel arms were taken as one 60 Moment about Point C Section Wi N Ri b m Mi N m Totals about Point C Fc divided across 2 locking levers 1065 804501 Using the FBD shown in the previous diagram the moment about point C was found and from that the force required to hold the entire easel s weight in the configuration above 4 26E403N The table labeled Ff Needed shows the calculations for the force necessary on the locking mechanism in order to hold the easel in place with only one locking mechanism engaged 61 Stress on the screws 0000000000000 on the screws Variable Value Uniis Value MPa 1 51E 08 150 780 4 26E 03 N 2 83E 05 m 2 Assumed Structural steel for yield point lowest of steels 4 00E 08 Pa Assuming that the screws used were made of the weakest steel the stress placed on the screw by the necessary compressive force was calculated The resulting stress of 150 7 MPa is less than the 400 MPa needed to cause the steel to yield and thus the screws are able to withstand the forces needed to support the easel with only one locking mechanism in place Bending Stresses sigma M c l 1 94E 07 E 19 40 2 71E 01 N m 1 27E 02Im 1 77E 08Im 4 sigma yield strength 1 35E 08 Pa To ensure that the moment caused by the weight of the easel would not cause the aluminum to yield the Bending Stress
56. p to its maximum of 10 Kohm it creates a large voltage drop and gives less voltage and current to the LEDs thus causing them to burn less brightly However when the resistance is turned all of the way down then the only voltage drop is across the 3 2 Kohm resistor This causes the maximum amount of voltage and current to be delivered to the LEDs and thus allowing them to burn brightly 35 Printed Circuit Board PCB The following is a lay out for the circuit that was adapted to a PCB This is the way the circuit is set up inside of the LED enclosure Careful consideration had to be taken when setting up the PCB in order to connect appropriate wires avoid crossing wires and avoid shorting components by placing them too closely This took trial and error and repeated checking of measurements Further more many custom foot prints had to be made to fit special parts like the switch battery and potentiometer LOLI x0 X0 X0 X0 X0 4 5000 qe Np Np US Ro Roo foe D e na na P 13 ET Do lid 36 Friction Hinge This friction positioning hinge produced by Reell Incorporated operates via a frictional device placed in the articulation between the two hinge pieces The Model PHC hinge is designed to provide constant torque throughout its full range of motion The hinge is capable of handling 3 9 Ib in of torque which is more than ample for the small LED enclosure Also it is capable of more than 10 000 cycles of use at maximum load f bow
57. quare 3 x 34 aluminum tube run through the center of it This aluminum tube was to have holes drilled in the sides so that it could be locked into position once extended The roller cage itself was to be adjustable up and down so that it could increase or decrease the elevation of the entire canvas holder This elevation adjustment was to be accomplished through the use of a gas spring Canvas Base After researching products that attach to a table top it was found most of these products made use of a C clamp Instead of using C clamps it was decided that making the base a C clamp itself would be the best way to attach it to a table top By constructing the base in a modified C shape it would allow it to slip over the edge of a table and lock down Figure 3 D view of Design 2 Gas Ti Eye Joint U Brackat 3 29 he Welded to Base Figure Side view of Design 2 2 1 3 Design 3 Materials This design was made of aluminum Lighting LEDs were also used for design 3 A prefabricated LED reading light was chosen as the illumination source for this particular design The light had three LED bulbs each of which was designed to last up to 10 000 hours The articulation for the light allows for a wide range of movement in order to reach every part of the canvas The light runs off of three button batteries that are easily replaced Canvas Holder The bottom
58. r people will be hurt in the construction or design process of producing the final product of the Easel 5000 Commercial copyrights and patents have not been and will not be violated with the construction or design of this adjustable easel Commercial products and patents are discussed in another section 3 7 Health and Safety The Easel 5000 warrants no outstanding health risks However there are a few 71 items to be cautious of when dealing with If the wire from the lighting source to the battery is exposed or damaged be sure the on off switch is set to the off position before handling with the exposed wire Be sure the on off switch is in the off position when replacing battery The easel is designed to reduce as many safety concerns as possible The elimination of easel legs facilitates wheelchair users The light source has no cord to plug into an electrical outlet Both the lack of easel legs and the cord highly reduces the likeliness of a tripping hazard when dealing with the easel The finished easel will have rounded edges so that the users will not get hurt on the corners In addition there will be no exposed wires to ensure higher safety 3 8 Social The development of the Easel 5000 is to aid in people with disabilities Main areas of concern socially are how well the artists with cerebral palsy are able to maintain their art in a comfortable environment and ease of use of this easel Although many of these artists may ha
59. roblems that ultimately had to be solved This was an excellent experience and we all gained life long skills that will be used many years down the line in our careers TI 7 BUDGET Managing a budget is never easy especially when creating a prototype When designing and constructing a prototype a general idea of where the project is going is always in mind but it is hard to keep track of details This results in an uncertainty of what is needed in the budget There are always last second things that need to be bought and accounted for in the design that one could have never predicted Also components that were thought to be essential end up not being used and need to be returned Another consideration with budget are the items that are not tangible Shipping costs and return fees ended up playing a big factor in our budget This was due to the fact many of our items had to be returned and incurred shipping costs Also many of our items were heavy and or large and required special shipping and extra charges Lastly some last minute additions were made to the budget Some products had to be order to put the finishing touch on the project and also a PCB was an added requirement and that added substantially to the budget However our group saved a lot on budget as well Many items were received as free samples or at a discount from willing companies Costs Date Vendor Cost Debit Credit 1 5 2006 1 9 2006 1 20 2006 1 20 20
60. s When the PCB came in Justin was in charge of soldering components onto it For documentation and reports CAD drawings seen in this report were completed by him These drawings took a lot of time since 3 dimensional CAD had to be learned throughout the semester 9 CONCLUSION Through the National Science Foundation team Easel 5000 was given the opportunity to build an adjustable easel that will be used in an art studio specifically for people with disabilities In particular this project was built for a man named Tom Depugh The easel project was done to redesign an easel that was previously built but was not appropriate for the artist The features of the easel include adjustability a battery powered lighting system and the ability to attach to a wheel chair tray Numerous design options were made for the easel from which an optimal was chosen The construction for the design was planned out and was executed in the second part of the course This involved trouble shooting redesigning construction and teamwork Ultimately the finished easel will be used in the Passion Works Studio and hopefully will be used by Tom in the rest of his future painting endeavors 80 9 1 Closing Remarks We wish the best of luck to the artist and assistant Much time and energy went into the development and construction of this easel and we know it will help Please do not hesitate to contact us in the future if we can be of any assistance Team 3 10 R
61. sign During a second test it was found that the sliding track that attached the extension arm to the base was causing a similar stability problem This was taken care of by simply eliminating the slide The slide was an unnecessary feature that only complicated the project Once the project was completed additional testing was done to the final product This was done by loading the canvas holder with a variety of weights and sizes The Easel 5000 Shown Holding Various ltems Including A Textbook Also it was used as a writing surface to ensure it could handle the similar motion of painting Then the adjustability was tested The easel was tested at a variety of heights to make sure it could accommodate many artists Then it was tested to make sure it could reach the height of a wheel chair Finally it was tested with a subject that pretended to have cerebral palsy This showed that even with a limited range of motion a user could reach the painting surface with ease The base was then tested to make 65 sure it could handle the moments created by the easel extension This was also proven successful The following series of pictures shows the testing that took place for the Easel 5000 66 67 68 69 The final bit of testing was done on the LED system which can be seen on in the last picture provided above The battery was tested to see how long it lasted in the system and how long it took to charge The battery l
62. sting the Canvas Holder Height 41 Canvas Clamp The sliding canvas clamp is the fourth mechanical part of the easel It also has rubber stripping which can be used to hold the canvas or other art surface in place Both the canvas clamp and canvas holder have a slot in the center of the supporting beams where an art surface could be place 3 Dimensional Rendering of the Easel 5000 42 Easel Use The Easel 5000 use is broken down into three major sections Adjustment Attachment and LED Light Use Adjustment Adjustment for the easel is controlled by a series of locking L handles When the L handles are rotated and tightened clock wise the handles are in their locked position When the handles are rotated counter clock wise this is the unlocked position When the handles are in their unlocked position this allows the joint that the L handle is located at to be adjusted L Handle Canvas Holder To adjust the canvas holder you must unlock the L handles on either side of the holder one at a time his then frees the holder to slide up and down in order to lock it onto the painting surface Using the Canvas Clamp 43 Adjusting Canvas Holder here are slots located in the canvas holder to hold thinner painting surfaces There is also rubber stripping to hold thicker painting surfaces Additional adjustment of the canvas holder can be achieved with an Alan wrench This adjustment can be preformed as an
63. t the battery to the charger then plug the charger into the wall socket e DO NOT PLUG IN THE CHARGER FIRST THEN CONNECT THE BATTERY DO NOT CUT ELECTRICAL WIRES DO NOT TAMPER WITH ELECTRICAL WIRES OR COMPONENTS DO NOT INTENTIONALLY SHORT THE BATTERY DOING SO WILL CAUSE THE LEADS AND THE BATTERY TO HEAT UP WHICH CAN CAUSE BURNS Do not disassemble the canvas holder as the frame contains electrical wiring 75 e Warnings for the operation of the LED were also included in this section as well o Warnings included WARNING DO NOT OVER ADJUST DIMMING SWITCH ON THE LED LIGHT o Recommendations for correct operation Do not attempt to turn the dimming switch past one full turn The preceding information was thought an adequate guideline for reasonable use of the easel and the lighting system Some specific conditions were outlined and appropriate recommendations were made to avoid injury to the user and bystanders as well as prevent damage to the easel 5 IMPACT OF ENGINEERING SOLUTIONS Easel 5000 will ultimately have a large impact Tom is a 44 year old man that has cerebral palsy dysarthria moderate cognitive impairment visual acuity trouble limited dexterity and limited arm movement Because of his disabilities many tasks become much more difficult One of Tom s favorite hobbies is art His artistic endeavors include poetry sculpture and he specializes in acrylic painting Passion works has given him an outlet to practice h
64. vas Holder The LED light can also be dimmed using the dimming knob located on the underside of the light compartment To turn the light on and off there is an on off switch located on the right side of the light compartment OO Switch LED Light LED Adjustment 4 Battery Use To connect the battery line up the red wire of the battery with the red wire of the connector then line up the black wire of the battery with the black wire of the connector Insert the male end of the connector into the female end of the connector To charge the battery remove it from its Velcro plastic box Next line up the red wire of the battery with the red wire of the connector then line up the black wire of the battery with the black wire of the connector and insert the male end of the connector into the female end of the connector hen with the charger provided plug it into a standard wall socket Charging is complete after approximately 8 5 hours Battery run time with the LED light operating at full capacity is approximately six hours Battery Pack for LED Light Velcro for Attachment Hole for Battery Wire gt jum RR A A gt Battery Enclosure 48 CLASS 2 POWER UMTS ERES LI Ur LETS bas 7 E 55s 1220 ADU uODEL PR INPUT AC 120v BHI CARPUT DC TET 20604 POLARITY E ao E DATE lt JAMN MAB 2052 MADE E rea 12 volt Battery Charger MAINTENANCE
65. ve abnormal muscle tone and movements they are still very talented The designed easel needs to be easy enough to use while giving the artist a nice interface so that they could paint however is most comfortable for them 3 9 Political The Easel 5000 was made possible by the National Science Foundation A budget of 750 was provided by the foundation that paid for all of the associated costs for the design and construction of the easel The NSF is a government funded organization that promotes and advances scientific progress in the United States by awarding grants and agreements for research and education in the sciences mathematics and engineering NSF Because Easel 5000 is part of an NSF project it is part of the advancement of technology in the United States 4 SAFETY ISSUES oafety is an important concern for any project For the Easel 5000 safety considerations for environmental mechanical and electrical hazards were evaluated The procedure began by generating a list of malfunctions and or errors in operation that could take place With the easel the primary area of concern was on the functionality of the locking mechanisms and joints The results of not engaging a locking mechanism or not taking care when positioning the device could result in injury to either the artist the assistant or both To avoid these injuries warnings were included in the safety manual specifically stating common errors and situation to avoid when usin
66. x Rubber Strip 23 Figure 3 Front view of canvas holder 2 x 1 x 4 Aluminum Channel 34 x 4 Aluminum Extrusions E lg Aluminum Sheet Welded On As A Cap NI i p du mu Bolt sa LA A H 7 Wingnuts To Lock Rubber Strip Mg Aluminum Sheet Welded On As A Cap P Bolt E EY Canvas Clamp In Place Figure 4 Top view of canvas clamp mechanism l 7 EASEL EXTENSION As shown in the materials list aluminum will be used to construct the extender arms With the use of this material the overall weight of the easel will be reduced with minimal effect on the mechanical effectiveness of the design This design will use three 34 x Y4 aluminum bars that are 24 long A single bar will be connected to the canvas mount on one end with an adjustable screw joint This joint will be accomplished with a U bracket and a wing nut The bar will also be pinned at the other end to the other two bars that will make up the arm Figure 5 is a side view of the design concept and illustrates the use of a pin to join the two sections of the arm together The two base beams will be attached to the Easel Base by two U brackets also shown in Figure 5 Because this joint is pinned free motion of the extender arms should be possible Ball Joint Pinned Joi

Final Report - BME - University of Connecticut

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