Hello,
I have a machine tending application that my company is trying to initiate using an existing machine. The workholding tombstone is on a pallet rotation device and can be spun by hand for loading and unloading. During machining the machine can initiate a power rotation to accomplish its work on multiple sides depending on the program. The machine manufacturer cannot retrofit an automated solution to provide rotation while the tombstone is in the load station. I am wondering if I could use a robot to replace the human rotating the tombstone to automate loading of both sides. Everything in my brain is screaming at me- unnecessary wear and tear, repeatable locating, payload strain... But I am wondering in general if its been accomplished and I'd like to entertain the idea as the solution is relatively temporary and the robot used will become a lab robot as we transition to the next phase- a pallet feed station with integrated power pallet rotation.
The tombstone itself weight about 600lbs fully loaded, the robot is wimpy with a 20kg payload. The kicker is that the rolling (rotating) resistance is very low and a person does not expend much effort to actually rotate the tombstone by hand. Of course this will require testing and force measurements which will be taken, but in general, has anyone ever done any supplemental push or pulls with the robot? Can anyone perhaps ignore the absurdity of the idea for a second and provide advice on paths to take to test it's viability? Can anyone provide any information as to the strength of the servos and how they relate to tool flange payload?
More info-
In the load station, the tombstone has a retractable pin mechanism that locks the rotation pallet in four locations, 0-360. The pin has the ability to be controlled by the robot by holding it in its depressed state, and when the signal is off the pin will ride (assuming this via its function) the bottom of the rotation pallet and as the pallet exposes its one of four sides the pin will automatically catch and lock the tombstone in place. That is to say, I can initiate pin retraction, start rotation and the pin will automatically lock the pallet in its next position (for a 90 degree move).
When locked, the pallet has approximately 1 degree of rotational play. To isolate movement, a cylinder with an attachment will guide an engagement to the tombstone and lock. I've made sure to calculate and mitigate any pulling forces from the cylinder or engagement mechanism on the tombstone, and any reactionary forces imparted on the cylinder from the rotational inertia of the tombstone side are mitigated using qty (2) 1" OD linear shafts supporting the cylinder; and the cylinder assembly will of course be stationary and stable.
editing here to add- What I mean by the above two paragraphs is that in my projection what would happen is the robot would rotate the tombstone until the pin engages and locks the pallet. The robot would then disengage or otherwise no longer hold the tombstone and then the cylinder would approach and engage to locate the tombstone as it would be free to move within that +/- .5 deg.
Thanks yall hope you enjoyed the read
