https://forums.autodesk.com/t5/hsm-post-processor-forum/post-processor-for-isel-ncp/m-p/6091338#M26174 Hi Ben<BR /><BR />I have also isel machine, like I have written in the post below I am almost there with changing isel post file. In my case erros in the first few lines were WPCLEAR and SPINDLE ON. WPCLEAR commands machine to whipe zero coordinates - I've deleted this line. Try deleting "ON" in line with spindle to turn it automaticly. It should look like this:<BR />N45 SPINDLE CW RPM13926<BR /> You can try my modified isel.cps maybe it will get you closer to error free post.<BR /><BR />If you still have errors, pls write more specific.<BR /><BR />EDIT:<BR />Ben, I saw that you edited your post during my reply. I am not programmer of any kind, I modified isel file with logic and reading, so I don't know if I can help you more. One thing I noticed that my machine freezes when circular interpolation is to small, it can occour specialy when finising passes are very precise. When you post file try to change setting minimumCircularRadius to 1 or above, it could help.<BR />Just for a test delete line that says:<BR />allowedCircularPlanes = undefined; // allow any circular motion<BR /><BR />this would not allow your postprocesor to write any circular interpolation (bad for machining time). If machine wouldn't state an error that would be your issue.<BR /><BR /> Tue, 08 Sep 2015 09:12:24 GMT Anonymous 2015-09-08T09:12:24Z