As students at Irvington High School in Ms. Berbawy’s Introduction to Engineering class, we were given the privilege and opportunity to spearhead a side project. When looking for a project that fits all of our interests, we ran into the E-nable website. We wanted to do a project that had a tangible impact and helped people. E-nable perfectly fit into these goals. We were extremely fortunate to have found this nonprofit organization, and were excited to utilize the tools at our disposal to help others.
Download all the files for the cyborg beast from thingiverse.
Use this graph to scale your hand accordingly:
3. Open the .stl files on Ultimaker Cura or any program used for 3D Printing
4. Use print settings as follows:
6. If it is necessary print your parts with supports.
7. Check the first layer of your print to make sure there is no error before you leave.
Possible errors include: prints not sticking to the build plate due to not cleaning the build plate properly, and extruder not being able to extrude material properly.
8. After it is printed remove the supports and use a sander to make the surface smooth.
9. Do this process for all the parts.
10. The parts needed to be printed include:
1 Gauntlet with Tensioner
4 Finger with Bumps
4 Finger Phalange
1 Right Palm
1 Thumb with Bumps
1 Thumb Phalange
4 Tensioner Pins
If all the parts cannot fit into one print, it can be split up into multiple different prints because the files are all separate.
Pictured below: First few layers of the phalanges and fingers being printed on an Ultimaker 2+
PREPARING FOR ASSEMBLY
When you 3D print your parts most of them will print with supports. You will have to use pliers to twist and remove the supports. You will have to use some force it does not come that easily. When it is removed it leaves a rough surface so it is recommended to sand it down.
2. Pliers used to take out the supports off of the palm
3. For the knuckles, this sharp tool or something of similar stature can be used to take out the supports in the crevices of the part.
4. This is a picture of removing the supports from the gauntlet with the pliers.
5. This is what the finished gauntlet should look like. You can sand the bottom where the supports were to make it smoother.
6. Because the screws provided in the kit did not fit through our holes in our fingers and thumb we drilled the holes to make them slightly bigger. Make sure to hold the drill straight when drilling to prevent the hole from slanting. You will also have to drill the holes on your knuckles to the same size. Make sure you drill the size to perfectly fit the screws given in the kit.
7. These 2 pictures have all the parts that should be 3D printed.
8. After you drill, use a screwdriver as well as the chicago screws in the kit to attach the finger/thumb to the knuckles. Make sure the orientation of the knuckle is correct (refer to the picture)
9. The next step is to use the longer chicago screw to attach all the fingers to the palm. (refer to image below). The length of the chicago screw will depend on how your prosthetic is scaled.
10. Next, attach the thumb to the palm.The chicago screws we were provided in the kit were not the correct size, so we used a different one from our engineering lab.
11. Next, we used the 5’’ chicago screw to attach the gauntlet to the palm.
12. This is what your hand should look like after the chicago screws are all put in.
13. Use the thick, elastic string provided in the kit to begin assembling the tensioners. First, tie a triple knot on the string. Then, thread the other end of the string through location #1. It will naturally thread to location #2. The knots will ensure that the string stays in place at location #1.
14. When the string naturally comes to the exit at location #3, thread it through the small hole in the crevice. Then, thread the string to location #4. The string will exit to the other side of the palm.
15. When the string is threaded to the opposing side of the palm, you will be able to tie the strings connected to (1) the index and middle finger and (2) ring and pinky finger.
16. Ensure the strings are tied together extremely tightly, and that there is as much tension as possible. It should be tight enough that if the fingers are pushed down (as shown in left photo), they will naturally/automatically rise back up to resting position (as shown in right photo).
17. Once all five fingers have been tied, you can move on. Next, you will put the tensioner blocks that were 3D printed into their respective locations in the gauntlet. For us, the tensioner blocks were slightly too large and couldn’t fit. We used a DeWalt sander to sand down the bottom half of the blocks. Then, we placed it in. The blocks should only be placed halfway into the gauntlet.
18. For the next tensioner, we used a rope-like string our engineering lab had. We began by tying 3-5 knots at the end of the string. Then, we threaded the other end of the string into the hole at the very top of the fingers. The string will naturally thread to the bottom half of the finger right below it. Continue to thread the string until it reaches the knuckle of the finger.
19. At the intersection between the fingers and palm, ensure that the rope is threaded through the same small hole that the previous (thick, elastic) string was threaded through. Then, follow the string along its respected crevice and thread it through the holes at the bottom of the palm.
20. Use the ½” in chicago screw at the holes in the two holes on the palm through a roll of the velcro *You will have to drill the velcro in order for the screws to go through.* Make sure to pre cut the velcro so it can sufficiently cover a wrist.
21. Similarly to the palm, use ½” chicago screws through the gauntlet and a roll of velcro. Make sure to pre cut the velcro so that it fits around a forearm.
22. Similarly to the palm, use ½” chicago screws through the gauntlet and a roll of velcro. Make sure to pre cut the velcro so that it fits around a forearm.
23. Apply foam (cut to fit) on any sharp or uncomfortable parts of the palm that hit the skin. This will ensure comfort.
24. Tighten the screws in the 5 holes at the bottom of the tensioner on the gauntlet. The screws should go into the tendons in order to ensure that the tensioner blocks don’t move.
26. This is the front and back view of the finished cyborg beast hand!