Strange print failures using Black Resin

So my last few prints have become progressively worse with the same odd printing failure, I am using V4 Black resin (in date) with a resin tank LT.

The printed models seem to smooth out and expand into each other only during the middle of the print (with not much effect at the top or base). I tried the same print file twice with pretty much the same result (in the second print however a small skirt now surrounds the raft on the first layer). See attached photos.

Has anyone else experienced this problem or have any ideas on how it can be solved?


Looks like your optics can use some cleaning.

Reach out to formlabs support for some manuals how to do it.

1 Like

Thanks for the advice, I’ve sent them a message now.
I don’t think the issue lies with the optical window or tank however as I replaced the tank and checked the window for dust/residue between prints.

Even when the tank and optical window looks clean, the galvanometers inside the machine and the mirror under the optical window can still be dirty. This happens over time.

There is a very thin layer of cured resin all around the base of the part. This is a sign of dirty optics.

ahh ok, thanks again.
I’m hoping this will be a simple fix as I’ve only had this particular machine for a week or so before these problems started.