Over the weekend I played with the laser making some test items using some

Over the weekend I played with the laser making
some test items using some work logos…

I discovered that sometimes my ellipse’s would not
connect to where it started, like a step off. At first I
thought it was only doing it on a 5 mm cut, but it
eventually did it @ 5, 10, 20 & 30 mm once in a while.

Would this be belt slipping ?

yes belts or motor skipping steps.
I notice a 3rd possible cause, the metal air vent (exhaust) is very close to the shaft of the X motor and could rub on it.

That looks like a belt or lashback issue. The motors could be skipping steps… Try doing a slower speed and see if that helps. Check for any binding on the gantry.

It may be a vector issue. I just did a few
runs drawing 30 or so random circle/ellipse
on construction paper all over the work space.

At this time, no issues at speeds from 5mm-30mm. Maybe it’s an issue with my original drawing.

I can cut 3mm hobby plywood from 4-11ma
at speeds from 10-30mm.

If this is material specific it may have to do with flatness of the material, I would be the first to say odds are that it is one of the previous items. Just another possibility to check of your list?

Did you do these images in one go or in different stages?
Looks good

Three separate files; etch the front with one file, etch the other side with another file and the final cut with another
file. I don’t know how to do it in one file with layers…yet.