Ramping issue 3d

[ajf]

I'm running 3.8.10 on a PRT standard machine. When I cut a large 3d file using a raster tool-path the machine does an abrupt change of direction when it moves to reverse its direction for the next cutting pass. It slams to a stop and then reverses direction with no apparent speed ramping occurring. The cutting speed is 100 ipm XY and 30 ipm Z. I've tried changing the various ramping speed variables, but the only one that really makes any kind of difference is reducing the 3d Threshold. However by reducing that I end up with a greatly increased cutting time for the whole file. I'm wondering if I've missed something or maybe someone can suggest a combination of ramping speed variables that I should try.

[bob_dodd]

http://www.shopbotblog.com/index.php/2008/03/a-ramping-the-vr-command-and-how-to-tune-your-tool-for-maximum-performance/

[ajf]

I had read Brady's article and tried what was suggested in it before posting my inquiry. Still haven't found a solution to the issue though.

[srwtlc]

Al,

Post a screen shot of the ramps that you were running and what move speeds for XY and Z you're running the file at. Maybe a preview image to see what kind of 3D file you're cutting would be helpful too. Sometimes it takes some testing and tweaking of the ramp settings to find the sweet spot by pausing and inserting VR changes while air cutting.