Sheetcam Post Processor

[islander261]

Hi

I did a quick search and couldn't find any reference documents on post processor files for Sheetcam. I have looked at the post files that came with Sheetcam and they look in general very similar to other CAM programs post files. Can someone please point me to a reference on the Sheetcam post processor file construction? Thanks in advance.

John

[chasxjs]

If you go on the forums at Sheetcam Les Newell will be able to answer any questions for you about the post processors. Also, if your a registered user and he does not already have a post processor that will work for you, he will create one.

[_Ogre]

way down at the bottom, back up anything you have

http://www.candcnc.net/index.php/downloads

[islander261]

Hi

Thank you for the replies. The CandCNC page that the link is for appears to be an old one with it's links broken. Not a big problem because the same information is available on newer pages on the CandCNC site. Reading through those posts was a big help, I now have a much better idea of how others implement advance cutting rules.

I am still running the evaluation version of Sheetcam as a test for right now. I want to be sure that it can be massaged to produce near perfect code for my old Torchmate 3 software. I am not in any rush because I have two other methods ( Gcodetools and ProNC Sheetmetal) to produce usable code with (some hand editing required). The supplied post still requires hand editing to remove a spurious G05 (a minor irritation that causes the controller to flag an error but not crash) but that will be gone today!

The one thing I haven't quite figured out is how parameters are passed from the path rules to the post. I'm sure that will come.

John

[islander261]

Hi

A quick update. After looking through a number of posts I understand how to check for short segments to corners and short radius arcs to either freeze torch height and or slow down torch. Now the part I am missing is how do you breakup long moves to a corner so a short section is added at the end? Is this where using the path rules comes into play or do you normally manually add segments at this point?

John

[acourtjester]

watch this
http://arclightcnc.com/sheetcam-tutorial-6-path-rules/

This may not apply to you but with the demo version of SheetCam you cannot use a THC

[islander261]

Hi

Thanks for reminding me about the Arclight tutorials on Sheetcam, I have watched them before but now paid attention to the cutting rules part. Yes, it appears that you cannot set the THC on and off in the cut rule in the evaluation mode. I found and figured out how to pass variable values to the post processor using the Set Post Variable dialog box. So this is where I am now.

I created a simple DXF to for testing cutting rules.
I create a new part and import the drawing (DXF).
I create an operation using my T1 jet cutting tool set up for my system (previously tested end to end and works).
Results of operation look good on (as expected) on screen.
I then select the simulation mode and set feel rate override to some fast speed and click on the start button, everything works as expected with simulation stepping through cut paths.

Now I decide to try and add cutting rules. I open my operation to edit and add cutting rules as shown in the Arclight video. No real surprise here every thing acts as normal. In view tool path mode everything looks good with cutting rules affected path parts colors changed. Next I select the simulation mode and set feed rate override to some fast speed and click the start button, Now a message box pops up displaying:

"Warning: WARNING: Feed rate is zero
Post processing completed with 1 warnings."

When I click the OK button nothing appears to happen (no simulated cut) and the feed rate display shows -0.0394 ipm as the feed rate and I can't edit it.

Then if I go back to the view tool path mode and run the post processor from the 'P" button I get a file that has the header and footer but no actual cutting G code in it.

Ok, I think this is how it works for some reason. I go back and edit my operation to have no cutting path rules, check view tool path mode and none of the path parts are highlighted any more. I select the simulation mode and the feedrate is shown as -0.0394 ipm. I click on the Start button and I get the same message box as before even though my cut path that is displayed in the view tool path mode is the same as the original one that worked. The only way I found to reset this is to close and reopen Sheetcam starting over. Is this the way it is supposed to work? I assume that I am doing something incorrectly to cause this, what is it?

John