Travel Limit Exceeded errors <resolved>

[Jim Klawon]

I'm building a ~4X8 plasma cutter. I'm running Clearpath servos through a C86ACCP to the Acorn board. I have the TX and RX boards connected as well as a Primeweld Cut60. The Clearpath motors are set up to home automatically on first enable.

The motion is seemingly being controlled as it should. I believe that I have the soft limits set correctly. The machine stops in the correct place at the ends of travel on each axis when jogged.

I have a breakaway sensor and a float switch connected. Both are functioning properly. I've gone through testing the ANLV reading with a 5v supply, performed a torch touch off successfully, and I've run the 51mm straight cut.

My problem starts when I load any of the nc files included with CNC12. If I load the "bear" and start a dry run the machine moves to what looks to be the first lead in position and then goes into shutdown with an "X Axis Travel Limit Exceeded" error. I've moved the XY0 position all around the table but it's always the same result. Same goes for the "hook". When I load the "plate" file and start a dry run, the machine moves the torch to the middle of the table and then goes into shutdown and giving a "Z Axis Travel Limit Exceeded" error.

I'm running a torch touch off prior to starting the dry runs. It's set at the safe height (30mm). I've toggled the THC on and off before starting but the results are the same.

Thanks for any help you can offer.

Jim

[tblough]

This is a work offset problem. While your machine and soft limits sound like they are set correctly. It doesn't appear that you have told the control where your part zero is located.

Without a report and a copy of the file you are attempting to run, we are just guessing at this point.

[Jim Klawon]

I was thinking that might be the issue when I first started. I've used CNC12 a good bit with a large CNC router table and I've had the same errors when using it and I forget to switch the origin from the bottom of the stock to the top or from center to a corner. In those cases the travel error is indicated when I graph the toolpath prior to starting the run. I'm not getting any travel errors when I graph the plasma toolpaths prior to starting a dry run.

I've moved my origin around to various parts of the table before restarting but I get the same results. Take the Centroid_Test_Plate.tap file included with CNC12 plasma software in the NCFILES directory for instance. I allow the machine to home (front left) and set the MCS home position. I then moved the torch to X~300mm and y~375mm and set the WCS XY=0. The Test Plate part is roughly 55mmX135mm judging by the graph. I figured that by setting the WCS far enough from the MCS origin I would be able to run the toolpath no matter where the origin was set on the part within the GCode.... I perform a touch off at the WCS origin and the torch touches off correctly and moves to 30mm above the stock. When I start the dry run the machine moves the torch to WCS X=635 Y=1395 before giving a "Z" axis travel exceeded error. I didn't think that the Z axis would have to move during a dry run but I had 30mm of travel in the negative direction and 84mm in the positive.

Next I loaded the Centroid_Test_Hook.tap file located in the directory mentioned above. Once again I set the WCS origin XY=0 at X~+300mm and Y~+375mm from the MCS home. The Test Hook part is roughly 35mm X 120mm. Once the touch off is performed I start the dry run. The machine moves the torch from WCS home to WCS X~64mm Y~20mm before giving an "X" axis travel exceeded error. That put my total X axis travel from the MCS home at just over +360mm. The soft stop is at X=+1275mm so I had a bit of wiggle room. This happens no matter where I set the WCS=0.

The other two files, Bear23x23.tap and Centroid_plasma_logo_20x4.tap, both result in a small movement of the torch followed by a "X" axis travel limit exceeded error.

I'm attaching a current report. I'm unable to upload the .tap files. I get an "Invalid File Type" error when I try to add them. I assume that everyone has access to the same files that I'm using. I'm loading them to CNC12 unaltered before the dry run.

Thanks again for your help.

[Jim Klawon]

Never mind. I'm an idiot. I loaded the file in mm and everything seems to be working now. I assumed that it would convert units

Thanks for your time.