This takes FDM printing with elastic filaments to the next level.
An iteration of the original Flexy-Hand, whose fingers are optimised to be printed with elastic filaments. This version was printed with Skin I Filaflex, Skin II also available.
Key Features :
- Hidden finger hinges, it's all in the geometry.
- Fingers compatible with the Flexy-Hand family.
- Each finger and thumb is printed in one piece. Using CraftWare customisable supports.
- Silent realistic articulation.
- Two thumb angle variants.
- Base mountable, can be used as a terminal device for an existing prosthesis.
Thanks to Jeff Erenstone of Performance Orthopedic Design for his recommendations and consultation along this design process.
Print the fingers in elastic filament (e.g. Filaflex) on their end like they are orientated in the STL file.
Print fingers with support to add stability. I used Craftware's customisable supports. Also reduce extrusion width and layer height until the thin skin covering the hinge areas have two complete perimeters.
Print the base hinges, then dab a glue to the hinge to keep attached to finger. I printed hinges with no infill and 3 perimeters (depends on scale) using Slic3r, this makes them nice and "spongy" adjust this if you want stiffer or more flexible hinges. The hinges at the base of the fingers are assembled a certain way round to aid finger return, please see section image to show this.
Print the bolt plug and bolt carrier in rigid material. The bolt carrier will benefit by printing the first few layers with the same coloured material as the hand to help concealment.
- At 100% scale, use an M12 or industry standard 1/2" HEX headed screw/bolt to mount to prosthesis.
Stringing the Tendons