E-Nable and Alderhand are pleased to announce the arrival of the Osprey! The Osprey was built in Blender based on the low-poly interior and robust components of the original Raptor Hand, but now sports an attractive fairing and a very durable and comfortable low-profile universal-fit bracer.
The osprey (Pandion haliaetus), sometimes known as the fish eagle, sea hawk, river hawk, or fish hawk, is a diurnal, fish-eating bird of prey. (Wikipedia)
This device was named the Osprey because it is a Raptor, but optimized for the use of heavy gauge nylon monofilament, most widely available as fishing line. The large mono has excellent Bowden properties, so the cables are pulled to provide flexion and pushed to provide extension. This device requires neither elastics nor springs nor any mechanical extension system.
Heavy gauge nylon monofilament is an excellent cabling material. It is generally inexpensive, and available as landscapers' trimmer line, nylon or Bridge nylon 3d printer filament, and as deep sea fishing leader line. Running through joints, it doesn't abrade at all, so there's no "sawing" of printed plastic. Nylon is very strong, so it is rarely a point of failure for mechanical devices. But probably its greatest quality is its resistance to linear compression, so it pushes as well as pulls, like the bicycle cabling used to change gears.
Elastic resistance is a major drawback to many assistive devices, because resistance reduces a device's grip strength. Furthermore, as an elastic-extended device approaches full actuation, resistance from elastics increases, so that it may be quite difficult for a user to grasp small objects. Designs which reduce or eliminate elastic resistance are a welcome development.
Pay particular attention to the new bill of materials. The Cyborg Beast, the original Raptor and the Raptor Reloaded hardware kits are not compatible with the Osprey. However, the Osprey does use the same hardware as the Gamma Raptor. Materials kits and tool kits should be available in the near future, so stay tuned.
In this version:
Elastic-free Bowden cable design; enclosed channels provide enhanced cable control
Vestigial dorsal extension channels can now be used for knuckle vise, other secondary tools, or electronics.
Fairing has a new aesthetic.
Pin-and-Proximal sets to manage tolerances ("A" is loosest; "D" is tightest)
Very durable low-profile universal fit bracer(gauntlet)
Palm v.2.1 The thumb has been rotated to better oppose the fingers. This affected the palm stencil, which was also updated.
Support material was removed from proximal phalanges. Let me know if you miss it. The hinge on the distals was bulked up, since it was a common point of failure under heavy lifting.
I added a new bracer/gauntlet. This fits the Osprey aesthetic better, and it has easier-to-remove support material. The old bracer will probably become part of the Gamma Raptor design.
Updated bracer and palm, and removed the old versions. Added 3/4" triglide buckle. Added proximal "key" to help determine which proximal tolerance best fits in the palm.
Update 2016-6-16 Instructions have improved a lot, so please have a look.
Replaced proximal and distal phalanges: improved mechanical performance.
Added a printable bracer stencil that will fit most clients just fine. After fitting, any overlapping leather can be trimmed if needed, but on most clients that won't be necessary.
Added sets of snap pins that are more compatible with PLA. The original pins were calculated for ABS, which is softer. So they were pretty difficult to insert in PLA builds. These PLA pins have longer tines that bend better.
Added D-Ring buckle. This is a good secure closure for the loose-weave nylon webbing.
Added pin tongs and a pin pusher, to help with the insertion and removal of snap pins.