A thank you to the first person to buy a Mk2 hand. Shapeways doesn’t tell me who you are, but I hope you stay involved as the design goes through it’s evolution.
A few images of the hand tendoned up! Manually pulling on the tendons confirms they work. Using monofibre tendons witin a PTFE tube means very low friction over tens of cm. Videos will go up next week since family stuff will be getting in the way this weekend.
Again the shop is here
Any feedback would be appreciated. Any features you think it needs, or any limitations that are just ever so slightly keeping you from buying one right now!
So the fully printed hand has arrived. There was a delay on shapeways end, but otherwise things are fine. I also received a few other things that I designed, and can be found on my shop here.
So far I’ve taken a few photos and done a paint job. I’m waiting for some resin to cure which will hold down the hand ends of the bowden tubes (PTFE tubing). This will let the tendons pull only at the joints that I want them to.
So hopefully over the next couple of days I should have a moving hand. I haven’t recently done a head count of all the working servos I have, and so may not be able to fully articulate it immediately, but it should be enough to show the flexibility at the fingers.
Hi everybody. It’s been a bit quiet recently but I have been working on a new hand that I think will certainly be a world first!
So what’s so new?
Well it’s printed in one piece! No assembly required, printed hinges and all that. 😀
Ok so slight admission here. First it’s in two pieces, but they are the hand and the wrist/stand. I hope to keep things modular and so kept them separate. It also allows me to use Shapeways discount for large object with over 10% density. It’s odd to have to add material in order to bring down the price, but it’s worth it.
Second slight admission. It’s intended to work with a bowden cable/tendon set up. So think of how a bike brake cable works. Essentially this allows me to make the fingers move without worrying about angles of the wrist. Soon I plan to sell complete kits with bowden tubes/tendons, servo’s, control electronics(arduino or raspberry pi). The hand should have reduced functionality if tendons run straight from joint to servo, but the bowden cable is the neater and more functional option.
So the advantages:
Hand printed in one go, so very little assembly work required.
Fingers tips move independently of finger base.
Fingers can also move side to side, although under-actuated (will explain soon).
Thumb is much more flexible than before and should be opposable!
Modular attachment at wrist, to allow for upgrades.
Stand can be anchored to any base via holes for 3mm screws. Also stand has 12mm cylindrical hole that can be screwed or slotted into.
Upgrades planned include forearm system with mounting points for servos. Also planned finger outer shells that clip on, to alter aesthetics.