Unplanned small cut-in / bevel at top edge

If you look at the picture given, the top edge cut-in of the shape is meant to be entirely vertical, but instead has a small shelf / bevel / something. Which looks kind of neat on this particular piece, but I’m setting up to cut some molds, and they absolutely can’t have this.

Is this a known issue? Any ideas what could be causing it?

can you share the Easel Project?
You’ll need to set the project to unlisted and copy the link shown on that screen and save the unlisted status setting as well.
Process shown in the 2nd half here: Simple Method - How To send a friend your Easel Project - YouTube

Agh, wrong one; here we are:

Comparing the output to the toolpath previews carefully, I’m more and more convinced that what’s happening is that while both passes are running correctly individually, the finishing pass in it’s entirety is running about .5 mm deeper than the roughing pass - which suggests that the problem might not be on the Easel side, but instead be somewhere in my workflow for the “re-zeroing the Z-axis” step of changing bits between passes, somehow (not sure how that could be flawed, given how straightforward it is, but it really appears something’s slipping down in the between-passes).

Looking at this design it would serve you better to carve this using the 2.5d workspace after converting this .stl into a .svg (flat vector art) and importing the design as a .svg file type.
This would give much more contol to depths and bit selection…

Carving this as 3d using the .stl i suggest selecting different bits, smaller for the finishing bit… also note that the workpiece thickness should be larger than the z size (plus the z position) but i noticed that your values are equal… but the material thicness must be LARGER so youll want to edit one of these values to make it so…

In the case of this design and going to SVG, that’s almost certainly true, but the whole purpose of the exercise is to get set up for cutting designs like this one (one side of a mold for a chess-like figure)…

…Which very much requires the whole STL conversion, so I’m aiming my efforts at building towards the workflow I’ll need on that pretty much exclusively right now.

I was unaware of the thickness requirement! Will change that and take another run, see if that makes a change (I’ve already tried to re-zero with much greater care than previously to no effect; shelf remains).

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For future readers with similar issue:

This particular issue is absolutely caused by having the material top surface and the STL top surface at the same height. As soon as I raised the material to 0.2 mm taller than the STL, the effect vanished.

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