Large Print Failures

Hello Peopoliers,

I bought a pre-assembled Moai 130 from Matterhackers a few weeks ago. Unfortunately, progress has been… slow. Leveling and settings were a difficult process, but eventually I was able to get small prints to work. Unfortunately, I am unable to make large prints adhere properly to the build plate, as seen below:

I stopped the above print mid-way, but only after verifying that the second raft (the one toward the D corner) had failed to adhere beyond the first layer. Now, for some info that will hopefully help you figure out my case:

Build Plate: Easy-to-level

Tank: FEP

Printer Settings (as of pictured print):

  • Y Size 900

  • X Deviation 100

  • Y Deviation 100

  • Smooth 50

  • Z Motor Speed 2

  • PM Motor Speed 12

Advanced Settings

  • Laser Power 59

  • XY Speed Set 4

  • Z Reset Position 1821

  • PM Reset Position 70

  • Z Follows 10

  • CompensateX 100

  • CompensateY 200

  • Z Initial Speed 2

  • PM Initial Speed 10

Heater Used: yes

Resin: Peopoly Model Gray

Software Used to Generate Support: Prusa Slicer (saved onto the STL itself)

Software Used to Convert to GCode: Ultimaker Cura 3.5

Cura Profile: Peopoly’s Official .04mm profile

Firmware: 1.18

Leveling Results (from DIY):

  • A: 10.6mm

  • B: 10.8mm

  • C: 10.6mm

  • D: 10.7mm

Ring Test: Successful, as well as a handful of smaller prints that succeeded as well.

Now, to save all of us some time, I want to give you a list of things I’ve already tried. My settings were once quite normal, but over time they’ve drifted with the number of things I’ve tried. Settings listed above were what was used on the pictured print, but boy is there a graveyard of the exact same (failed) print.

  • Tried printing at laser power 60. Didn’t really help, so I dialed it back to 59.

  • I imagined that maybe the peel force was too much, so I tried printing at Z follow 10. It still failed at 2.

  • I imagined the force was too WEAK, so I tried printing at PM Reset Position at 70. Failed (just assume failure from here on out). It failed at 60 as well.

  • Tried every Z Reset from the range of 1819-1824. 1821 seems to be the best result, but didn’t actually finish the print either.

I am currently trying to print with the above settings, except Z Follow is 0 and PM Reset is 80. Trying to go extreme and see if it makes any difference. At this point I’m hoping for a stroke of genius, this is getting very exhausting. Any suggestions are appreciated!

Is there any reason you are not using Asura to prepare you print? I know that those running Macs have trouble with it, but for me on Windows it works pretty well.

The supports it generates are optimized for the Moai and you can use calibration files to minimize distortion.

I would recommend trying it for model orientation, hollowing, support generation and gcode output.

The temperature of the resin and of the printer’s enclosure is essential. If the temperature is risen to around 30 C the resin becomes more fluid and easier to print. Try this. It may solve your problem. This is a known issue on Moai 130.

@rowiac Prusa’s autosupport feature creates very few islands, to the point where I can just press the button and save off an stl. I have heard that Asura requires a lot more personal attention, which is time I’m not willing to lose.

That said, I would have switched to Asura if it weren’t for the fact that the supports created by Prusa came out quite nicely on smaller prints. Even in my picture above, the supports were quite successful in corner A. Since the supports are only failing on one side, do you still think it would be the supports?

@Raoul I already have the heater installed and running inside the printing chamber. I haven’t thermometer-tested it, but that should be keeping things in the 27-35° range. Unfortunately I can’t crank the temp higher than that, or my roommates would kill me!

Update: Z-follow of 0 and PM Reset of 80 didn’t help at all. I fell back to z-reset of 0 and PM reset of 60, and am now trying to perfect my leveling. I’ve heard that leveling tolerances have to be way more precise on lower layer heights, so I am trying to get all the test columns in a neat 10.6mm range.

@Kuann I wouldn’t say that Asura requires a lot of personal attention. It’s easy to add to and delete the auto-generated support. At the least you could try it and see how the auto-generated supports look compared to the Prusa software. You could also try matching the parameters of the Prusa supports to what is used in Asura.

I have the PDMS vat, so I was forced to level precisely. I’ve been able to print with 40um layer height reliably, although once in a while a single support will fail and I get a flat spot on the model. I’ve been able to correct this by adjusting the supports in that particular area in Asura and reprinting.

Also, as I mentioned, even though my printer is in a room at around 19°C, the Peopoly heater is able to bring the chamber up to 30°C if you allow it to equilibrate for a while. I don’t think you will need to raise the temperature of the room if you are using the heater.

@rowiac I tried releveling more precisely, and am running the print again. When I get home from work I’ll know if it did any better. If not, I will give Asura a shot and see what I get!

Your leveling and ring test worked so it’s back to user’s error
Can you show us your orientation of the model?
Maybe try a different, lower resolution profile

@rowiac Re-leveling did not make much of a difference, so off to Asura I went. I had success with the Asura supports - something about the lowered plate surface area due to a lack of raft, or due to the increased thickness of the supports. Not ideal, but it was nice to have a print work after so many failures!

However, the fact that I still can’t print with a lot of surface area on the bed is disappointing. I had my eye on some supportless miniatures, and now it seems I’ll have to print them just like anything else. I haven’t seen supportless minis cited as something the Moai cannot do, so I’m still thinking I did something wrong.

Also the thick supports eat up a lot of resin… the print failed because I ran out of resin partway through. Although the supports aren’t entirely to blame, this was a big print.

@peopolysupport, I couldn’t get a screenshot of my Cura project that made it at all possible to see through all the supports. I uploaded the Cura project instead here (you may have to paste the link into a browser tab):

You may note that the supports are a good deal thinner than the Asura supports. From the looks of things, though, the print failed during the raft creation stage - before the supports would have had a chance to break.

@peopolysupport I tried printing at a higher layer height (100 microns). Still failed. Reprinted the ring test though, just to be safe. Still works.

Weirdly, the ring test prints on the side of the bed that usually fails. This despite the fact that the ring has a small raft. No idea what’s going on there.

Try increasing the z reset a bit more, maybe 1824
Use thicker supports and support tips as well
if it fails on the side than it’s most likely due to the FEP vat, your leveling stats looks fine so keep them that way

@peopolysupport I mentioned at the beginning of the thread that I tried every Z reset from 1819-1824. Increasing to 1821 improved my results, but they got worse at 1824 (near total failure, only first layer adhered). So that won’t work.

I’ve just determined that the support height and support tips are stable. I tried a print that had previously failed where I lowered the Prusa rafts BELOW the print bed in Cura. In other words, I printed ONLY the supports, with no raft. The result was a successful print.

Something about the Prusa raft seems to be screwing the prints up. The Prusa rafts fail at the second layer somewhere… as you can see in the picture I posted in the initial post, there was full build plate adhesion on the first 1-2 layers. It wasn’t until later that there was layer separation. I know Prusa is not recommended by you and you’re not obligated to support their software. I’m just concerned that I won’t be able to print anything that has high contact with the build plate on early layers.

What do you mean by being the FEP vat? Do you think I need to replace the film? It’s still clear and free of air bubbles, except for a little wart in the middle.

i didn’t know that you had prusa’s slicer to generate support, since there were no pictures
Generally, Chitubox or Prusa’s raft base is bad on Moai or any other SLA printers, the way it forms usually causes resin cupping and make it difficult for adhesion
I always recommend to use either circle base, reverse cone base or none in any slicer

@peopolysupport Have you read my initial post? It includes a lot of information about my situation and workflow, including that I was using PrusaSlicer for supports. I also didn’t supply any pictures in Cura because all the supports made it hard to see anything meaningful from any one angle. That’s why I supplied a Google Drive link to the Cura project! But here are some pictures to help things along:

Would you mind telling me more about resin cupping? I’ve never heard of it.

Sorry that i missed your first post
Let’s start with the base, try printing with out the raft base, leave just the cone
For the support, try making thicker support and bigger support tip, also reduce the amount of support
And for testing, print 1 model in the green zone where it got failed to see the result