7/15/14 Modular Hand Issues

Today was spent on Rhino, trying to find a good way to apply the snap fit design to the existing model of the Cyborg Beast.  We printed a prototype to see how well the snap fit works when printed.  However, after losing track of the number of failed prints, we decided to make do with what we had.

The Intermediate Gauntlet (yellow) is supposed to clip into slots on the test block (red).  However, the left arm of the gauntlet failed to print in one piece.

From the prototype fitting, I learned that more length was needed to add flexibility to the rigid plastic.  In the Rhino model, the arm was made thinner and slightly longer.  Also, clearance space was needed in order to ensure a snug but easy to remove fit.

After this test it was decided that the peg should be part of the hand itself instead of the gauntlet.  This is because we figured it would be easier to apply the peg to existing hand models rather than needing to change current hands when adding the slots.  The slots will be permanently part of the intermediate gauntlet.
The most trouble came from leaving space for the slots on the gauntlet.  When the model is completed tomorrow, I will include a picture of it in the next update.
On the bright side, the fingers of the RIT Arm were finally printed.  All we need are the pins, then we

should be ready to assemble tomorrow.

RIT fingers being printed

While Sam worked on making these hands more modular I (Alex) spent my day trying to make these hand designs easier to print. One of the most annoying parts about assembling these hands is the long Chicago screw used to mount all four fingers to the palm. To try and fix this I am designing a 3D printed pin that will slide in to the palm and replace the long screw.

Above you can see my pin (shown in red) and the palm (shown in grey) that it will fit into

Due to my relative lack of experience with Rhino it is taking my quite some time to get this pin designed but the more I work with this program the better I am getting. After we get the RIT arm assembled (hopefully tomorrow!) I plan on putting together a formal documentation paper showcasing the printing, assembling, and potentially modification of the RIT arm.

Well that's all for today, look forward to some completed RIT arm pictures tomorrow!

Alex + Sam