Adaptive clearing toolpath bug

[Anonymous]

Hello,

I'm experiencing an issue when running an adaptive clearing toolpath.  I don't understand exactly what the problem is, but I have seen it across different models and different files. 

When running an adaptive clearing toolpath, the machine takes a series of fine step-downs, a roughing pass, then another series of fine step-downs and so on. 

The error I experience is that the roughing pass cuts into the area machined by the fine step-downs above it. It cuts the right shape at the wrong place, as if the zero moved when it began the roughing pass.  Needles to say, the tool isn't behaving the way it looks in the simulation

Has anyone else experienced an issue like this? Anyone found a solution? If anyone has suggestions I'm ready to test them and report back with results. 

Technical info:

The machine is a shopbot buddy, the computer runs shopbot 3.8.62. The controller box firmware is 218. Post processing set to Shopbot openSPB

A clue:

I examined the gcode lines before the error occurs and noticed it was the only time it used J3 instead of M3. The shopbot cheat sheet mentions that J3 can be calculated in either absolute distance (SA) or relative distance (SR).  Maybe this explains the "moving zero"

[HughesTooling]

Did you have smoothing enabled? If you did give it a go with it off. If that works look at the minimum chord length and try increasing the size. Other thought would be an arc in either the XZ or YZ might be upsetting your control. Are you using a generic post processor?

Mark

[martin.dunschen]

Hi @Anonymous 

If I understand you right, this problem does not show in the stock simulation in Fusion, but on your CNC machine?

As @HughesTooling points out, it could be an issue with the smoothing in which case we would like to ask you to submit the f3d file here. If it does not appear to be related to smoothing, but is due to an arc upsetting your controller, it would still be helpful for us to have the f3d file.

Regards

Martin Dunschen

[HughesTooling]

@Anonymous  You might want to download NC Corrector so you can backplot the actual code before machining, does the machine have backplot?

Mark

[Anonymous]

Hi @martin.dunschen ,

Thank you for your reply. Unfortunately, this is not my own design so I cannot share the fusion file. Naturally this makes it difficult to diagnose the problem.

I've discovered the same problem on another file of my own creation, can we pickup the conversation over there? The documentation is much more complete. https://forums.autodesk.com/t5/fusion-360-manufacture/adaptive-clearing-toolpath-bug-laser-gun/m-p/8...

Thank you