Update on some printing problems

I thought I’d post a little update on some printing problems I’ve been having.

I had a period of time where all my prints were failing dramatically. After talking with Formlabs support, we replaced my roller holder and LPU. I also replaced my resin trays. That markedly improved my prints. Small prints came out consistently very well.

But I continued having problems with big prints. Specifically, if the prints were located near the edges of the build platform, they would often have small missing features near those edges. I can often mitigate this problem by adding extra supports that protrude from the xy-extremeties of the object being printed. I don’t know why, but if there are supports just beyond the xy-profile of the primary object, I do not get failures.

Given that my warrantee is about to expire and this problem hasn’t been resolved, Formlabs is sending me a replacement printer. That gives me 90 days to work out the kinks and ensure the printer is running smoothly.

I had my Form 3 replaced with a Form 3B recently.

Small prints continue to work well. Big prints continue to be a problem.

I am noticing a trend in how the big prints fail. It seems to be worse when the print is close to the edge of the build platform, but it can happen when the print is in the centre as well.

The method of failure appears to come from layer-shift in the supports. If a layer-shift is big-enough, the support won’t get connected to the main object it is meant to support. At that moment of disconnect, it appears some resin remains stuck to the resin tray, i.e. the elastic surface. This resin stuck to the tray results in the laser not being able to service that part of the tray, and a cascade of failures extend-out and often results in a print failure.

The tell-tale “mark” of failure on the print tray is a thin spiderweb of cured resin on the resin tray surface, if you catch it early enough. If you catch it late, it might be a big pileup of cured resin in the tray.

I have been getting these failures with Grey V4 at 50 micron. From other threads I can see this resin has caused some problems for other people, as well.