I posted the following in one of the generic CNC forums on here, and have since read a few posts where people suggest using Mach to control a bender. Here is my post:
Ok, I have an older mandrel bender that has been updated with an Automation Direct / Koyo PLC but it is still a manual machine. The bend angle is not electronically measured or controlled; instead it uses a mechanically adjustable stop and limit switch to stop the machine at the desired bend angle. It is VERY obnoxious to get this dialed in - I want digital control. The machine still uses a control panel from the 60's with industrial type switches as well - most of which have very dirty contacts and can be intermittant.
I would like to upgrade the machine in 2 phases:
1. Add a rotary encoder and some form of digital angle display that could toggle between the current bend angle of the machine and an adjustable set point. (Or have 2 displays, one for current angle and oe for setpoint) I am thinking about trying to do this part with the PLC that is already on there - but the high speed counter alone is around $300 to read the encoder, which is another $90 - not to mention a display unit at $135 and some rather expensive software to program it (and I would have to learn how!)
2. I plan on adding a tube positioner with stepper or servo control. This would be 2 axis - one for tube rotation and one for linear position. I would really like to have a desktop computer controlling things at this point so it would be easy to program. When bending you position the tube in the 2 axes I just mentioned then bend to a certain angle and do it all again.
I can handle all the mechanical parts no problem, but am struggling with what way to go as far as computer controls and software. Everything I've seen so far on this website is for XYZ control and doesn't really translate well to benders. Also, the machine has a BUNCH of solenoids that need to be operated by the controls - I believe there are about 16 limit switch inputs and 12 solenoid outputs on the current PLC being used.
I would like to hear ideas on how to control this beast. By the way, it is capable of bending up to 6" OD steel tubing - so it is a beast!
So, how would you implement this in Mach? Is there a way to reconfigure the axes to work well for bending? One axis would be a linear feed. One a rotation angle. And the last variable is bend angle which involves switching a hydraulic solenoid on until the rotary encoder reached the desired bend angle. I guess this could be done as an axis?
Thank you!
Jason