Well, this is interesting, thanks in advance for helping me. I made this machine all frame is 4" X 4" X 1/4" tubing gantry same. The gantry runs on a rail system. Stepper motors ( Nema motors ) can not move or shake any thing by hand, using a vertical torch from Thermal Dynamic with a rack & pinon the X & Y travels with rack and pinon as well. Using a board from CN4. parreal port. X motor are set at  509.1702372 step per inch/ Velocity 93.6/ Acceleration/ step per 33.17149/ Y is set 526.7068/ Velocity 93.6 /  Acceleration 33.171/ A is a slave for Y set as same as Y. Hope this is good for now.

Ratpack

The real trick to plasma cutting is to keep the motion as constant velocity (feedrate).  The plasma cutting function depends on this to cut smoothly. IF your accelleration is too slow MACH3 will slow dramatically in arcs and circles . THis slowdown effects the cut quality. SO the process ends up being a compromise on low end cutters that cannot achieve HIGH acceleration rates.

Testing and GOOD note keeping goes along way here as each type and size  plate cut MAY require a different setting to cut cleanly. Finding the MAX acceleration that your machine can handle will help as well. MORE testing (;-).

Just a thought, (;-) TP

Thank you BR549 I was thinking the same thing, because when I cut 3/8" or 1/2" plate it is not bad only on lighter gauges. So in hand acceleration is a key factor.I will lower this and do more test.

Ratpack

You need to RAISE the acceleration to as fast as your machine can work without errors so it can react faster.

(;-) TP

Thanks I will defiantly will try to raise it some time today and re calibrate avery thing all over before cutting a test pieces.

Ratpack