Black layer 1 print times? (Form 2)

Hi there.

Yesterday I set off a print, fairly large, the raft probably covered half of the platform. The printer started ok but layer 1 seemed to get stuck, it didn’t move for over 30 minutes so I cancelled and tried again, same result.

I reset the printer same result. I re-oriented the model, same result. Changed to mini rafts, same result. I cleaned up after every failed attempt, layer 1 had adhered perfectly. I wondered if maybe there was too much contact and the platform was sticking, but there’s no attempt to move the tray at any point, and wouldn’t this error?

Tried printing another smaller model, perfect result.

So I’m thinking the printer doesn’t like this model. I’ve checked it in Blender, Meshmixer, re-imported the stl to Fusion, the model is fine.

Any advice?

The first layer(especially with black resin) takes a very long time to finish as it does multiple passes to make sure it adheres to the platform. Did the display still show it was doing the first layer?

Yes, but the spinning dial made no sense, it displayed the later had been completed a long time, 30 minutes or so before I cancelled the print the first time.

I’ve set off many other prints with admittedly smaller rafts and they’ve been along the same lines as any other resin, and I’ve tried most of them.

I have since noticed a dirty great void in the tank when cleaning it, I think the laser layer has come unstuck, about the size of a cigarette end. I didn’t inspect the tank overly closely when I first installed it but I would have noticed that. My suspicion is this was created on the same problem print.

When Printing Black devices, i’ve found that the first layer does take a really long time. I thought like you did, that it would fail and it was stuck. I let it go and it eventually picked up a faster pace as it got to the real model. The Raft seemed to be a really long print. I’ve reduced RAFT height considerably and removed labels… anything to shorten the time.
As for the void, that is an indication of either a dirty spot on the lens (laser side) or a dent in the printing base… the cured black material cannot bond to the aluminum surface. Check the base surface for imperfections.

We also had an issue at one point where it printed the material and it bonded to the tray, rather than the base. Once we adjusted the height of the base (for the first layer print) to be a bit closer, it stopped making errors. Although we had to scrap a tray because we couldn’t get it cleaned well enough.