Strange shrinking problem with a flatcar

[Lemosteam]

@SkipGear could you share a photo of a part where that produced a square corner?  I suppose if it were not perfect one could add the same amount to the model to be a sacrificial sanding plane.  Would not take long to remove 0.25mm of material on a flat sanding board.

[Sokramiketes]

At least for my printer, this is how I would do it..... Printing at .025mm layers, the ramp down on the Photon takes 10 layers so make a .25mm bevel on the build plate side of the model. The more complex the model, the more challenging it cousl be to get it right as inside corners could cause an issue.

Ok, I see what you're saying now.

But, wouldn't the bloom be the same dimension for each of the first 10 layers?  Meaning the undercut should be a shelf instead of a chamfer?

[Lemosteam]

Ok, I see what you're saying now.

But, wouldn't the bloom be the same dimension for each of the first 10 layers?  Meaning the undercut should be a shelf instead of a chamfer?

No because the printer ramps down the exposure over those 10 layers so the bloom becomes less and less with each new layer.

[Sokramiketes]

No because the printer ramps down the exposure over those 10 layers so the bloom becomes less and less with each new layer.

Ahhhhhhh.

So the undercut chamfer does need to be calibrated though.  At least a lot more tightly than the picture framing idea.  And I don't think it would result in a sharp outside (or inside) corner.  The bloom will be balloon shaped, rounding it off.