Layer shift and distortion in DLP print

[curious aardvark]

I get similiar results with my printer.

Given how much of a pain in the arse a resin printer is when it doesn't work perfectly. I have yet to do any real investigation.

My instincts are two fold.

1) aluminium reflects uv light better than anything else, so i believe there is a lot of lateral scatter that effects the bottom of the print and means you simply can't print a detailed first layer.

2) calibration.
Logically if the print sticks to the fep in preference to the build plate - then one of two things is going on.
1) the calibration process has the build plate too close to the fep film and the resin stick to the fep plate in preference to the buuld plate.
2) the cheap 'fep' film I bought from aliexpress isn't actually 'fep' and naturally sticks to resin much more than proper fep.

I've had a lot of good stuff from aliexpress. But then I've also had items totally different to what I ordered which I could not send back. The 'return and refund' service does not allow either return or refunds.
I've also had items missing from orders for which absolutely no response has ever been had from the vendors.

So I'm leaning towards: not all FEP is actually FEP.

That and uv reflection and back scatter from the build plate making the resin stick to the fep film in preference.

Not sure what i can do about the FEP.
But I am looking for something I can cover the build plate with that doesn't reflect uv light anywhere near as well as aluminium.
And also find out how to calibrate the plate properly.

In your case, I'd guess it's probably a calibration issue.

[anvoice]

Thanks for sharing. My FEP comes from the manufacturer of the printer, and the build plate is sandblasted so it should mostly scatter the UV light. Not sure if that actually helps or not. Strange thing is I printed at 50 microns without issue. I'll redo the build plate calibration since I have no other leads to go on.

Aliexpress is unfortunately the only decent source of electronics and other components, when it works.