2013-01-02

Shoulder InMoov for New Year, 3d print it!

Happy New Year to all of you crazy robot fan and builders!
I have a little present for you ready to download. You should be abble to build the shoulder with succes if you follow the tutorial I am going to post in the Assembly Help tab.

I know some of you have been waiting, but I had to redesign and reprint this a few times before to finally get it the way I like it. My initial design and prints didn't have enough DOF, and my second design was too large to stay in a human size range. I tried to use parts of the bicep, but came to realize there was to much pressure/torque on the worm gear, so that also had to be redesigned.
initial design shoulder 3d print
This was the initial design of the shoulders

Redesigned torso DOF 3d print
Then I redesigned the whole thing to get more DOF

3d printed robot
Final result of the torso with shoulders


Of course it could be much more improved but I don't have enough time and money for to do that. For exemple, the printed screw threads could be replaced with linear actuators, making it more accurate and strong. But I try to manage my wallet for this project, and I know a lot of you are in the same kind of position. So if you've got a thick wallet, you can replace those parts fairly easily. I have made the space for it and added attachment holes for to be adaptive. The others with a smaller budget can print and play, if it breaks, well, reprint. Or get them printed by Shapeways in stainless steel for a reasonable price.
inmoov screw 3d print
These are some of the broken and rejected prints I didn't throw away.


But be reassured, I've had these parts on for several weeks now and I have been making them run already quite a few hours, sometimes mistreating them badly, and they are holding. The main breakage I had, were during the implementation of the servos speeds and positions feedback, plus a problem with my power supply, which would make my servos act erratical. If they go further then the limits, they break.

Anyway, like I say following the tutorial should make it easy to construct.

I also need  to upload the torso because the tuto concerns it too. My problem is that I'm not finished with it.
You see I need to think of the vertebra attachments to the torso and that might change a bit still.
We will see...