[ssutton]

I have fought intermittent jerkiness issues with my machine running certain files. This issue pops up when I import a file that was created not using true arcs but rather line segments. Today I turned off all the check boxes for Mach CV and turned up my look-ahead to 200 lines. The machine ran a the job smoothly.........what detrimental effect (if any) will turning off the CV have on my cuts?

Thanks,
Scott

[ger21]

Today I turned off all the check boxes for Mach CV and turned up my look-ahead to 200 lines. The machine ran a the job smoothly.........what detrimental effect (if any) will turning off the CV have on my cuts?

IT sounds like you didn't actually turn it off, but just turned off all the options. If CV was turned off, it would stop at every line of g-code.

[louieatienza]

My findings mirror that of yours and what Gerry explained. Really howevevr, if you do mostly 3D work, most likely your CAM will generate lines instead of arcs following the contours, and the tighter the tolerance the more the lines.

The Mach3 document on this (ArtSoft USA - Documentation) is very informative. The lookahead can actually be set up to 1000, though this might not be a realistic number depending on the speed of your system. The checkboxes on the bottom right do not affect CV until you reach a hard corner. On my CAM all outside corners are made as radius toolpaths with tool comp, but pocketing does produce hard corners. In my small experiments I did not find much if any of an advantage with them on or off, but again, this might be more dependant on your CAM or the type of material/toolpath you are cutting.

[jwolin]

This article may be of help in understanding the actual issue and why it is happening. CNC Mentor.com: | Blog | Docs | New Doc