Machining errors moving outside of workpiece

How To Machining
1

I was trying to machine a cutout on a scrap piece of 18 mm baltic birch. It was a tight fit and some of the path of the cutout toolpath ran outside the edges of the workpiece. The actual cutout part was within the edges of the workpiece.

i used a 4 mm two-flute downcut spiral but with a 6 mm shank. 100 ipm with 3 mm DOC. Ramping. The cut on the interior of the workpiece was exceptionally smooth but on the side where it went out the edges of the workpiece it messed up terribly.

I am speculating that cutting into free space, however briefly, and then returning sideways into material t the full 100 ipm feedrate caused the nachine to skip steps.

Does this sound plausible? This was a test run.

cause

2

Very possible if you have belts. If your machine is so equipped, you may have a loose one. Do a search on the forum for belt tightening.

3

Its a Shapeoko 5 Pro with VFD. I’m running it again right now on a new (bigger0 piece of baltic, we’ll see how it goes

4

The same file with the same feeds and speeds and the same setup except all the paths were completely contained within the stock ran just fine.

5

Could be, but I’m really cheap and often cut around the outside of stock trying to eke out the most part from the smallest stock.

Maybe set up a series of test cuts in a piece of scrap?

Is it possible that the outside cut ran beyond the machine’s working area (which will result in lost steps).