Hurky Jerky

[cnc_works]

I'm cutting a mold (about Y5", X48", Z5" if it matters) just like the one before it. What had been a smooth traverse over the 3d sections of the mold in the previous toolpath, started to exhibit a momentary stop, barely discernable, just enough to give the cut a jerky motion, at what may have been cusps or nodes on the curves. In fact, the same thing happened on the raster rough cut in 2d before the final 3D smoothing cut, just a fine hesitation at the end of one curve before starting another.

Both drawings were prepared the same, as far as I can tell...same program, computers etc. What could have changed?

Thanks for any input!

Donn

[cnc_works]

Errr, duh. PRT96 standard, Ascension Geckos, parasolid files into Mastercam then into Mach3.

Donn

[srwtlc]

Donn, check your CV settings. If you have CV tolerance and or stop on angles checked, it could possibly cause it. Also check the settings page and see if CV feedrate is on.

I ran a bunch of tests last year that exhibited this same scenario with transitions from one flowing curve to another when it shouldn't have. CV on without any helpers was the only way it would work right.

[cnc_works]

Yup, you called it Scott. I don't know why I assumed that I could upgrade the software and have it leave the old setup intact, even though it is supposed to.

Thanks a lot for reminding me.

Donn