Wednesday, January 8, 2014

prosthetic hand: milwaukee prt.3 (bob roth prosthetic hand)

This past Sunday a post was made on the e-NABLE Google Group about a hand made by Bob Roth of Tulsa, OK. After seeing the video of the hand in use, I just couldn't get the design out of my head. The pivot on top of the wrist allowed for independent movement of the fingers on the prosthetic hand and the linkage design in the fingers allowed for progressive movement of the individual sections of the finger. The design was simply BRILLIANT. Again, I just couldn't get the design out of my mind. At first I starting capturing screen shots of another video of the modeled finger movement that was posted, thinking that I could just reverse engineer it, and then something compelled me to contact Bob directly. Before the day was over, Bob and I had spoken on the phone and he had agreed to share the design with the group and to send it to me as well. Anyone who knows me, knows that this is a bit out of character for me, as I tend to be a bit introverted and shay when it comes to talking on the phone or just meeting new people period, but something was driving me to make contact and see that I could get this design to start experimenting with Shea's hand. 

Bob sent the files Sunday mid-afternoon. I had trouble with the Solidworks file that Bob sent as I received a Solidworks Assembly that had no Solidworks parts when I would open it. Over the course of Sunday and Monday I was able to open the .SLDASM in E-drawings viewer and then export the parts as a .STL. The scale was off on the drawing, but this was something that I could solve in Rhino or Makerware and I would need to do this anyway for various size hands. I imported the file into Rhino, scaled the model and then aligned the components to aid in printing. I sliced the files and got started on printing the hand Monday night. Bob also gave me the file for the modified new and improved finger. I ran it through the same operations and created files that I could upload to the e-NABLE R&D drive and also uploaded to Thingiverse to share. I awoke to a print bed of parts that I could play with today. 

Bob contacted me tonight and mentioned that I shouldn't use the first fingers, and I would advise anyone else the same, but I just wanted to print both sets out so I could see the printed results for myself. I am currently printing a set of the new fingers to assemble and test along with the first set.  I took the night off for my wife's Birthday tonight, so not much else to report at the moment.

The Thingiverse files can be accessed here:

Thanks to Bob Roth for being so gracious to share his amazing work. We all owe him a huge thanks.


Have Blue said...

Frankie, can you send me a copy of the SolidWorks assembly? I can dump it out in IGES or some other format that you can work with more easily in Rhino.

Have Blue said...

Just watched the video of the hand - I didn't realize that Bob had added a second axis of motion control to it! You said it and I'll say it again - BRILLIANT!

Frankie Flood said...

I agree. It IS BRILLIANT!!!!