开云体育

Well I thought I was home free and over the hump when I got the three axes
running off one port on the laptop (Compaq 1510 2.2Ghz P4) with Mach2 RC2.




This a router running simple rectangles, either multiple cuts to break
through or using tabbing and cutting the tabs after the first pass. In either
case I'm losing the zsteps in the last cut, so if I leave tabs 1/8" thick and
run I lose Z .125 with every tab. If I single step through the code I lose
nothing.


I'm posting out of BobCad and MasterCam (using VERY simple code, g90, g0,
g1,g03). All movements are in absolute except I and J in incremental. I'm
only feeding at 50 IPM at 2k steps/inch at Z and 120 IPM at 1.02K steps inch
in x and y, well within the capabilities of 25K pps. I can single step the
drives at anything up to 400 IPM x-y with an indicator and it doesn't drop a
step, put it an NC file to run and everything goes to hell unless I single
step that. Has anyone been through this?




Frank Carpenter

Hi Frank:

As a test lower the Z acceleration. This is the most common cause of this.
Rapid reversals of the Z is notorious for lost steps due to the huge inertia
of the Z axis. Usually it is the eaxis with the most torque required.
Thanks,
Art
www.artofcnc.ca

Art,

And of course that was the problem, thank you. Sometimes when the floodwaters are rising you forget to paddle ;

Frank Carpenter