2012-06-09

Nice day today, InMoov right hand has been featured on Thingiverse!
I wanted since a while to transform the wrist of the hand because of a lack of DOF. For to do that, I had to dismantle the whole hand...(again)  I decided last night to give it a go. Worked something in Blender after creating some gears with Openscad using "Parametric Herringbone and helical gears" from canadaduane in Thingiverse. Actually since it was the first time I used Openscad, it took me a while to figure out the whole thing.
I printed the parts this morning and made a test with the Arduino. I had to adjust some parts of course but the whole thing finally works. I will soon put the parts to download on Thingiverse.


Here are some pictures to illustrate the building of this new part.
After printing you should have five parts.  
Remove with pliers the support. Fix in the bracket the servo MG995. Use the Arduino to set it to 0 degree.


Use one of your spare actuator from your servo. Cut it and fix it to the small gear as shown. It shouldn't be oversized.
Grease the big gear before setting in "rotawrist2".
Drill and tight fit the gear to "rotawrist3" through "rotawrist2".


Use hot glue gun to position and fix "cableholderwrist1" to the top of the servo. This will help to guide the rods into the center hole.


Close the whole thing and tight the 3 screws on perimeter. Make a test run with your Aduino. This is the position you should have when your servo is at 180° for the left hand

Now it's time to glue "rotawrist1" to "robpart2V2". Once glued detach "rotawrist1" from "rotawrist2". Start running the rods from your servos up to each finger. (Use the Arduino to set your servos at 0 Degrees) Don't twist the rods and make sure the upper rods run through the upper parts of the fingers, run the lower rods through the lower parts of the fingers.
This is where you are going to test your patience and skills. I use twisers for to do the job.