This thing that can be called an assistive device requires two intact hands to operate a relatively fragilehttp://www.thingiverse.com/thing:6986,http://www.thingiverse.com/thing:10337,http://www.thingiverse.com/thing:206231), each finger is a single piece composed of 12 flexible parts, which can be configured in 8,388,608

I configured this version with two 4-degree-of-freedom fingers and one 2-degree-of-freedom thumb. You can activate specific bending of the fingers by passing the tendon wires through the holes in the outer corners, and not activate other bending by passing the tendon wires through the holes in the middle. I tilted all three fingers backward and fixed them with rubber bands.

Finally, I installed my fingers on a hand-grip platform, allowing me to use all ten fingers to control all ten degrees of freedom. As you can see from the video,https://youtu.be/ws8d-CH5kBk)，Moving your fingers elegantly takes some practice! I hope some smart people can print their own models and connect them to a row of RC servos.

Print settings

Printing brand:

MakerGear

Printers:

M2

Raft layer:

I don't care

Support:

None

Resolution:

0.2mm

Fill in:

20%

Remark:

The flexible fingers are printed using PLA, but ABS or PETG might also work.

Use a line width of 0.4mm to print, to ensure that the curved parts are printed correctly.

Print three fingers, one finger base, one palm base, six rings, two small finger rings, and two thumb rings.

Post-print processing

Assemble

First, insert the finger base into the groove of the palm base and use a few drops of super glue to bond the two together. Insert each finger into the groove of the finger base

Pulling the wire may require some patience. It may also take some trial and error to find the right length of wire. I used 30# Spectra fishing line, but you can also use durable buckle line.

First, I run lines on the back of each finger, and each line passes through the outer hole of the back corner. I tie it at the top and attach the other end to a rubber band.

For the "thumb", I ran two more threads through the anterior lateral corner holes of the two groups and tied each thread to a slightly wider thumb ring.

For the "fingers", I start from the middle of the finger and thread the line through the anterior lateral hole. I tie it at the midpoint, then attach one end to the regular ring

Next, start from the top of the finger, and then pass two threads through the outer front group of holes in front of the finger, but stop when you reach the other thread. At this point, pass the thread through the central hole in the lower part of the finger. Tie each thread to two additional regular rings

Slightly stretch each rubber band, make your fingers tilt slightly backward, and put each rubber band into a notch, then loop it around a corner. Don't put too much tension on each rubber band. I'm still experimenting with the best rubber band route, and you may need to find the method that works best for you.

At this point, you should be able to pull the ring to bend different parts of your fingers.

Customized part

Operation

The palm base still needs some improvement to make it more comfortable, but I've already found a way to hold this thing:

Hold your hand so that your fingers are away from you and your "thumb" is facing your face. With one hand, insert your index finger into the curved ring closest to you on the lower side of the operation, and insert your middle finger into the curved ring on the upper side of the same side. Next, insert your ring finger into the curved ring on the upper side of the other side of the operation, and insert your little finger into the curved ring on the lower side of the other side of the operation. You may need to use a rubber band to connect the rubber band line between your middle and

Repeat with the other hand. Now, put each thumb on a thumb ring and operate the alien "thumb". You may need someone to help you put all the rings on each finger.

Clamp your palm with the palm base. You need to try different positions and directions to find the most comfortable way to operate. Now just pull all 10 rings to move your fingers. At this point, you're a lot like a baby, trying to move your fingers without hitting your own face.

Category: Mechanical Toys