Metal Bending Machine Feed Data Calculation and Dimension Calculations

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AKA_knowledge23

Hello All,

I'm currently working on some PLC programming for a metal bending machine that uses two cylindrical spindles (one on the top and one on the bottom) that use a motor to rotate back and forth and rotate a rectangular piece of metal that is fed between them. A clamp attached to a linear actuator feeds the sheet metal between the cylinders.

Problem 1: In some parts of the code, the original programmer asks the user to input material diameter. I scoured the internet to find information on this, but most of the info was relevant to tube bending. Diameter implies that a tube of some kind is involved, but when I visited the facility, they were using flat sheets of metal. I thought about the outer diameter of the roll of metal that was fed into the machine, but if that was the case, the material diameter would decrease as more metal was used and it would not make sense in the code. A flat sheet of metal has an infinite radius, so could the material diameter be adjusted for thickness? I'm out of ideas guys and I really need some insight and reference information if possible, so I can read about it myself.

Problem 2 Background (check the paragraph beneath this for the problem regarding this function): The code uses a counter that tells the logic controller that one bend has been completed before the feed clamp feeds the metal between the top and bottom cylinders for the next bend. What happens is that the feed length input by the user is fed to the PLC. The PLC uses a sensor that measures the distance the feed clamp moved after it is retracted back to its home position. A comparison block in the PLC checks the sensor value and compares it with the Feed Data input from the user. When the sensor value reaches the Feed Data value or surpasses it, the PLC commands the feed clamp to stop and the material clamp fixes the metal in place so it can be bent.

Problem 2: Following each bend, the Feed_Data value is reset by the PLC to be the feed length of the first input minus the top cylinder bend angle of the last input (there are 6 groups of inputs on the touch screen and each one contains the variables, Feed Length, Bend Angle, and number of repeats. The PLC alternates between the top cylinder and bottom cylinder to bend the metal. The user chooses which cylinder they want to start with).

Problem 3: Could someone please explain what is the calculated top/bottom spindle setting and why is it important? How is this calculation justified? Could anyone please offer some insight? (In the program, the spindle setting is calculated by taking the sum of the spindle radius and material radius. It seems to be half the shortest distance between the center of the spindle and the outer surface of the other spindle. I did not see a distance changing mechanism when I looked at the machine but I think I missed something.)

Problem 4: The total tool setting reading is calculated by subtracted the total offset from 2000. The total offset is calculated by adding the top spindle radius, bottom spindle radius, and the entire material diameter. Could someone please explain why a fixed number like 2000 would be used and how the total offset is useful to the technician, since it does not seem to be used by the machine?

(the PLC calculates length by making each unit of length equal 0.01 inches so 2000 is the same as 20 inches. The machine interprets analog values on an integer scale from 0 to 24678)

Please note that the material radius, and spindle radii are not used by the machine, but they do show up on the interface. I don't understand why those values are not important to the machine. Does it mean that those values need to be adjusted manually?

I understand that this thread is a bit lengthy, but I would like to thank you in advance for any comments or insight you can spare.

Best,
AKA_knowledge23

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AKA_knowledge23

Any help would be very much appreciated. Thank you! =)

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AKA_knowledge23

>Any help would be very much appreciated. Thank you! =)

I see. Well I thought the community would be more helpful than this especially when I contributed a lot of effort beforehand. At this point, I've gotten far enough where there is really no point in checking this post. And moderator, please post this.

Best,
AKA_knowledge23