Hello,
Please let me know if this question should be placed in a different area of the forum, I wasn't quite sure.
We are working on an unusual project where we have converted our trusty PRS Alpha into a CNC Aluminum bending robot for a large scale sculpture. The goal is to try and created an automated routine for this as there are approximately 1,000 pieces in total that will need to be fabricated.
So far , we have it about 80% complete, though are hung up on the last part which is to figure out a way to have the shopbot compensate for a decrease in Z value height when picking up new stock material, which it then places into a holding jig, prior to bending the metal "fingers". This video shows the loading and unloading operation:
https://vimeo.com/89213148
There is a vacuum cup attached to a bracket on the Z axis that moves to the stack of aluminum stock, lowers to the top surface of the top piece, and then activates a vacuum switched by the relay board in the controller. It then loads the piece into the fixture. The question is, the next time it does this, the stack of stock material will be about 0.098" lower each time as the material is removed. How to compensate for this, besides hard-coding that diminishing thickness into the loading file?
The one thought is to put a small electrical probe (machine screw) that would make contact with the top of the metal stock material and then use a similar routine that the Z-Zero plate uses to use a closed electrical loop as an input, thus the diminishing material height would not be an issue as it would always just lower the Z axis, searching for the top of the next stock material.
I can code a bit, but when I dig into the various referenced routines involved with the Z-Zero file, I'm not entirely sure how to extract and re-purpose the relevant code into what we need. Any suggestions from those of you that like automation challenges?
Thank you.
Rob Ley