Quote Originally Posted by bradywatson View Post
It looks to me like the first thing you need to do is power up the machine & shake down every axis with considerable force (don't overpower it) - and see if you can track down if the pinions are loose. Those cuts are horrible.

You should NOT be using a ball end tool unless you are doing 3D or decorative engraving. The tapered bit should be square. Your RPM is too low for plastic - you want to be in the 16-18k range, and slow that move speed down. Shoot for 1.2,0.7 for your XY, Z speeds and adjust as needed. No sense in running 2" per sec on a 2" tall letter, right? Do your cuts in multiple passes using a smooth ramped entry (in profile toolpath options in VCP/Aspire) - 1 pass may be too deep causing the motors to stall.

You may also want to adjust your VR settings to the numbers I lay out in the Ramping Article - but check for mechanical slop first.

Let us know how you make out. What model machine are you running...Assuming it is a Standard?

-B
It's good to hear that we should expect more from the machine. It is a standard shopbot with HSD 4 hp spindle. It appears that 18k is max rpm.
I was not involved in setup or construction of the machine, so this is quite helpful but also unfamiliar.
So, to check pinions I should turn it on and run the spindle warm up routine, zero it, then I push it physically - by hand? Is there a way to look for what area to tighten? On the gantry or the sides? I'll certainly give it a once over and tighten anything that seems loose, just trying to figure out what to look for.
The collet is new.
Thanks