Losing Position Cutting 3/8" Baltic Birch on Desktop Max ATC

[pisgahbanjos]

Hey all,
I am running into an issue cutting through 3/8 inch Baltic birch on my 2020 Desktop Max ATC. Partway through the cut, the tool begins losing position, specifically when the X or Y axis reverses direction at the extremes of the 10 inch diameter circle I am profiling. As soon as the machine changes direction, the cut starts to drift off path. The bit then rubs hard against the sidewall, causing resistance and eventually sending the tool into a spiral and crash.

Cut parameters:

Tool: 0.25 inch downcut, two flute

Feed rate: 2 ips

Pass depth: 0.0975 inch

Chip load: about 0.003 inch

Material: 3/8 inch Baltic birch

The cutter is not brand new, but this operation should not be putting significant stress on the steppers. This feels more like position loss or mechanical drag showing up when the machine reverses direction under load.

Has anyone seen similar behavior on a Desktop Max? Any insight into troubleshooting steps, whether mechanical, electrical, or toolpath related, would be greatly appreciated.

Thanks in advance. Patrick

[scottp55]

Hey Patrick
Have you tried an aircut?
Does it return to 0,0 correctly after the aircut?

leave spindle off and do M(ove) command all over at Move speeds, any noises at all?

Check all connections for looseness and corrosion(including all computer peripherals).

Have you tried doing it with a Profile/Spiral toolpath to keep all forces fairly even?

That's it off the top of my head except for Static and machine grounding.
scott

I agree that my 2013 Desktop spindle would have no problems with that setup.

[pisgahbanjos]

Defiantly happening because of and during the cutting. Air cutting brings it back to 0,0 no issue.

Using a spiral tool pathing for the circle cut.

all connections look good.

[scottp55]

I imagine you've tried it without DC going?

You've cut this exact file before?
No small artifacts at that particular location in the file?
Made ANY recent changes to file or machine?

Running out of ideas
scott