Weird "smashed" looking compression on my dental arches

After a year of printing the same way the very first batch after my Firmware update this past weekend produced prints that appeared to be smashed/melted at the very ends. For troubleshooting I’ve replaced the LT Vat with an Orange tank, slipped in a new cartridge of Grey v4 Resin and cleaned the glass under the vat - which really didn’t seem dirty. There’s been no change in print quality. I still get the strange defect at the end. It seems that everything within the print up to that point is fine.

Currently I’ve rolled back my firmware and Preform software to see if that will make a difference. I’m printing the same file plus another file from a few weeks ago that printed fine. Any other suggestions? I’m still waiting for Formlabs to get back to me.

My best guess is that you’re lacking enough support underneath the arch, also it may be flexing too much as it builds up from instability.

Thanks for the response. I don’t use supports on these, the way they’re built doesn’t require them. I’m working with Formlabs right now (well, waiting for them to respond to the test prints they asked for). The optics test print failed miserably. It looks like it might be a laser focus issue.

Looks like a bad peel on one the layers causing it to adhere to the tank. If you scrape the tank down you may find it stuck there. Be gentle when removing it, drag the scraper over the edges slowly and try to work it loose.

Formlabs seems to think it caused by dirty Galvo mirrors. I’ve received instructions to take the unit apart and clean them.

It makes me a little nervous.

It looks like it’s mostly printing fine until it reaches the arch, which very likely means that the arch is falling apart and causing errors (due to lack of support)

I always orient my dental models flat onto the build plate. That way I know there will be enough support for the full model. Works for me every time.

I’ve always printed my models upright. The way I prepare makes allows them to work that way. These are hollow BUT the middle center is filled. It’s not like an empty horseshoe type arch. Here’s a couple of pictures of what the model looks like when it’s cleaned off. Hopefully I upload that correctly. See how the front end is distorted? It’s looking more like a laser focus issue. Hopefully Formlabs can sort it out. Thanks for the feedback!

interesting. What design software are you using? We use 3shape modelbuilder and all of the models I print are horseshoe arches that are hollowed out and they work perfectly on the build platform. Just takes a bit of force to pop them off the build plate :slight_smile:

We don’t have any dental software. Our models come directly from the Ortho practice already based. They use 3Shape there. I simply do a distal plane cut at about 100 degrees to give me a slight angle when the model is sitting upright, then I hollow it. After that I lop off a good portion of the base (these are working models) I send it to the Formlabs slicer. I use Meshmixer for all of my edits. In this particular case I digitally ditched around the teeth for banding. If anything it allows me to get a bunch more models on the build plate.

I’ve done a few typical horseshoes but not too many of them.

If there’s any laser issue, then it would affect the rest of the print, so it’s likely a mechanical issue.

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