Help with prototype for a hexagonal bar straightening machine.

i think this problem can't be solved with mechanical adjustment rather you can adjust the motor horse power

My professional opinion.
Anyone fell free to add...

Well , I do think that 1 motor per 2 Rotor bolts would be a good solution
meaning it would require 2 motors rather than 1 motor, while the axis of rotation of both motor should be same there should not be any runout or indifference between them with respect to rotation axis

the same can be acheived by 1 motor given you increase the horsepower and the transmission should have highest possible efficiency i.e you can use Belts for the same

with regards
Ritesh

Thanks for sharing your setup, Leonardo. From what you described, it sounds like the core issue is the manual detection and adjustment process, which slows everything down.

One improvement could be to integrate a sensor system (like laser scanners or dial indicators) that automatically detects the high points on the bar as it enters the machine. This way, the rollers can adjust dynamically in real-time without manual intervention.

Another idea is to explore a multi-roll straightening system, where more than three rolls are placed at strategic angles around the bar. This allows the machine to apply pressure from multiple directions, helping to correct bends without needing to rotate the bar.

If budget allows, adding a servo-controlled actuator to dynamically adjust pressure at each roller based on sensor feedback could help automate and speed up the process.

Lastly, consider looking into existing industrial hex bar straighteners used in high-volume applications. Even if you’re building a custom solution, borrowing proven mechanics or concepts can save you a lot of trial and error.

Hello, here is an example of what the device could look like. The hexagonal rods must be driven separately. It is a simplified representation