Mars 2 only printing first layer of files

[andywood]

Hello

I hope somebody can help me resolve this.

I have a new Mars 2 (arrived last week). It printed perfectly 3 times and then suddenly started printing only the first layers of a file. See the images below. The print continues on the UI (percentage keeps rising) but it actually stops at these layers and doesn't print any more.

I have recalibrated 4 times and all the prints following recalibration have turned out like this.

I've tried printing different files.

The files that failed have printed fine on other printers.

Thanks for your consideration. I haven't posted before so please tell me if you need any other information.

[cliffyk]

I see nothing cured,  as though the curing lamps are not coming on or the LCD shutter is bad. Can you see that they are by peeking in though the vent holes?

What exposure times are you using? are these models "flat" on the platen or using supports (hangers)?

Try slicing and printing this:

LCDTest.stl (89.2 kB)

It is a 120 x 68 x 5 mm block, flat on the platen:



Remove the resin vat and platen, and do a "dry" print of the file with a sheet of white paper over the lCD--do you see a bright rectangle like this:



If not either the curing lamps or LCD screen are bad...

[andywood]

Cliffyk Thank you for your response, I appreciate you taking the time.

In the second image of my post above you can see that first layer seems cured (or am I interpreting it wrong?). I have to scrape those discs off the build plate.

The models use supports. They print without issue on my two other Mars 2 printers with the same exposure times.

Thank you for the LCDtest file. I sliced it and did the dry print. I saw the bright rectangle (the texture in the light is coming from the paper, not the screen):





I almost wish I hadn't seen the rectangle so I'd know what the issue is!

Any ideas what I could test for next? Thanks again for your time.

[cliffyk]

Try actually printing the test file--if it prints correctly we know we need to look elsewhere.

Another thing to check, what lift speeds are set in the "Print" tab of the settings dialog?

[andywood]

Thanks for these ideas!

Lift settings are like this:

Bottom lift speed: 90 mm/min
Lifting speed: 100 mm/min
Retract speed: 150 mm/min


I tried printing the file. Seems only the first layer printed. I got this thin sheet of resin:

[andywood]

Hello Cliff and everybody

Just to update you that somehow this particular issue was resolved.

I wish I could tell you how, but quite simply I calibrated for the umpteenth time and did yet another test print and it printed the file completely, beyond the first layer.  I don't know why this particular time it started working, so can't leave any wisdom here for posterity I'm afraid.

Very strange!