We adopted our son from Shanghai this spring.
He has a mild case of Spastic Cerebral palsy that is making his left side of the body not working perfectly.
His left hand is bent with muscle tension all the time. We need to stretch and do different kinds of training several times a day.
I had the idea for this hand for i while but haven't had any experience in 3D design.
But then a friend of mine sent me a link to this challenge and that gave me new motivation.
It took some time to learn a software program and a lot of starting all over, and when I got a design right I printed, tested and sometimes had to redo, but now I got it :)
So this is my contribution for the Thingiverse #AssistiveTech Challenge
For my son right now the hand was made for only one purpose, to stretch.. but it turned out that somehow he also can now hold the hand in a upright position he never could before.
that's a huge bonus, it will really help him when playing.
hANDi both stretch his hand out by pulling it up against the "overhand plate". At the same time it stretches his fingers up.
One thing I have to add to this section now after designing the add on "pen holder"
is that at the same time he gets the stretching he needs he can draw, and that really helps him with hit motor skills. It is amazing to sit down and see the progress he makes in using his arm.. amazing!!!
Other purposes for the hand is muscle rehabilitation. cause of the spring tension.
I hope this hand can help other kids to with CP or some kind of hand injury.
So i made sure to do the design so it can be used on both left and right hand ;)
I also added a alternative arm between the ring and hand plate that has a 20 degree upward angle for more stretch.
About the size, our son is 4 years old and the finger tips of this design is a perfect fit for him... if it doesn't fit, just scale it up a little ;) or ask me and I will help you with it :) If you are using fusion 360 I can invite you to the project folder :)
Also... I have some options in fusion to extract the files. I am new to this so I dont know what file extension is the best to share? I have seen some people upload .STEP files.
Do you want me to do that?
After printing I added some soft materials to the inside of the arm ring and under the plate that lays on top of the hand. Then i used Velcro to tighten it all up.
I used springs and fishing line to attach the fingertips.
Latest recomended parts for complete hANDi:
- overhand_2_2_left.stl or
- thumb_stag_2_2__45_anlge.stl or
- hand_stag_2_1.stl or
- fingertip_2_0_middle_fingers.stl x3
- Knut 2 or Knut or to easy tighten the lines:
- Addon_hANDi_pennholder_1_1.stl (file here or in thing page Add on hANDi pen holder)
- Added video and comparison photo.
- Showed his physiotherapist and got big thumps up :)
- Designed a New thing to make it easier with all the knots.. Meet Knut
- New thumb strut with 45* angle and two holes for the line for different thumb length.
- New Overhand parts with double holes for the line. This to easy fit different finger length.
- New version of Overhand parts, now with mount holes for addons.
- Designed a addon, a pen holder, see pictures below.
- New hand ring for better stability and lower filament use ;) bigger but smaller!
- New pictures of latest hANDi version with new arm ring and add on :)
- New Thing: Knut 2
- New thumb strut with a different angle, our OT recomended us to try this one :)
Hope my English is understandable ;)
(some kind of error with the markdown in this section, I have tried to make understandable by adding < br > for new line.. hope it gets fixed)
Easy to print parts
- Arm ring is easy to print standing up with wide part down, using support material.
- The same with the fingertips, standing up with the fingertip facing up.. and they need support material to.
- The two arms, the one for the thumb and the one that holds the ring and plate together is best printed on the side, with support material for the hook.
- The over hand plate is best printed flat with the fingers floating.. using support material.
The add on: pen holder is printed flat down like it is suppose to sit on hANDi. support material needed for the holes ;)
- I printed all with 0,2 layer height, support material and 50% infill to make the parts strong but maybe it doesn't have to be that hight.
I use a "printrbot simple metal" without heated bed and bad bridge settings so with a better printer some of these parts don't even need support material :)
Other materials needed:
- 2 springs
- 6 M4 screws and nuts
- about 1 meter of fishing line and a google search on fishing knots ;)
Or use cable lug to lock line, see image a bit down on this page ;) (<--recommendation)
- Download my design Knut 2 or Knut and use between spring and the fingers:
- Some sort of soft mateial to put on the inside to make it comfortable.
This was the first step of my design. right before bed time we sat down and did this :)
I used fusion 360, this is the first real 3D design I have ever done :) version 1.0
Complete hANDi with updated parts including pen holder... version 2.0
YouTube and pics
Here is hANDi with my multi attachment Knut, find Knut here: http://www.thingiverse.com/thing:1075335
All parts plus Addon pennhoder (old hand ring)
hANDi with the pennholder
Make locks for the fishing line using
use the locks like this.. just thread the line trough and press together with pliers :)
With new arm ring! fits mush better to the arm and is more comfortable :)