this post was submitted on 25 Nov 2023
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Any ideas as to what I'm doing wrong?

This sphere has a ridge on it, and I've had miniatures come out with the base to be slightly offset giving a bit of a ridge.

I'm using a Halot One, lychee Slicer, and Anycubic Water Wash resin.

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[–] [email protected] 33 points 11 months ago* (last edited 11 months ago) (1 children)

That's just the foreskin.

Seriously though, if that happens on multiple prints, maybe there's something going on with the Z screw?

[–] [email protected] 4 points 11 months ago (1 children)

I've paused all the prints I've done (I've only had the printer for about a month), I'm hoping that's the issue. If not I'll definitely look into the z axis screw.

[–] [email protected] 2 points 11 months ago

I'm not a resin expert, but that sounds pretty plausible. Good luck!

[–] [email protected] 13 points 11 months ago (1 children)

Pauses do weird things with 3D printing, though it’s generally better with resin printers, it will still suffer. Higher end models have ways of compensating, but will still see weirdness.

It’s generally a loss of precision/placement of the bed, and (on some faulty firmware) missed layers from the read.

This looks like it could be the latter, or potentially even both.

I’d definitely try again without a pause, and if it goes properly just avoid pausing moving forward. A firmware update wouldn’t be a bad idea either, if available.

[–] [email protected] 2 points 11 months ago

I updated to the newest firmware before I started printing (I've only had it for a month or so).

I'll try without the pause, and then look into the z axis of that doesn't solve the problem.

[–] [email protected] 10 points 11 months ago (2 children)

It may be because I paused the print to check raft adhesion. I'll try some prints tomorrow without pausing.

[–] [email protected] 9 points 11 months ago (1 children)

Pausing a print usually causes me problems. I'm not sure why. Temperature, maybe.

[–] [email protected] 3 points 11 months ago

That's what I'm beginning to suspect, other prints that have had ridges or offsets I paused as well.

[–] [email protected] 2 points 11 months ago

Im pretty sure that you have that issue cause of the pausing then. I paused a print once, during one of my first prints, and after resuming it failed. So i just made it a thing to never pause prints again. It just messes with the print for some reason.

[–] [email protected] 6 points 11 months ago (2 children)

Are you printing this near the center of your print bed?

I suspect that the object is not fully peeling off the FEP film, but just pulling it up for some of the layers. When it eventually releases the print continues.

I think you should lift higher, maybe double it to 10mm, to make sure that it completely separates from the film every layer.

[–] [email protected] 4 points 11 months ago* (last edited 11 months ago) (1 children)

Given my experience, this is what I would say too. Not separating from the FEP. Very specifically, I notice he's printing a sphere. These are known to cause suction-cupping, and generally the symptom of said suction cupping is...this.

[–] [email protected] 2 points 11 months ago (1 children)

Suction cupping causes the print to rip from the build plate/supports, it wouldn’t cause this. Especially since it continues along as if a few layers were cut out of the file, which just isn’t something caused by suction cupping. It would essentially need to be stuck to the FEP to such an extreme degree that the stepper motor is unable to move.

[–] [email protected] 2 points 11 months ago* (last edited 11 months ago) (2 children)

Suction cupping causes the print to rip from the build plate/supports

It can cause both, actually. And it continues along, because it eventually gets up high enough in layers that the additional lift manages to break the suction effect. Finally allowing the resin to drop out of the top of the model and for it to cease happening. If the FEP film isn't tight enough, or has loosened up due to wear, it absolutely can follow the print upwards without disconnecting for a few layers, without pulling the print off of the build plate.

I, quite literally, run one of the few professional shop for repairing FDM and Resin based printers in the USA and have 12 years of experience in the field; engineering systems, designing products, and even had a few successful 3D printer kickstarters. Sure - without looking at it happen in person, I could be missing something here, but I highly doubt it.

Additionally, I've seen this exact failure mode on the peopoly Phenom due to its excessively large FEP vat, as mentioned - due to suction cupping. The model never separated from the build plate. The motor doesn't have to cease moving, you merely need too little lift, and a loose FEP film.

[–] [email protected] 1 points 11 months ago* (last edited 11 months ago)

A loose FEP wouldn’t cause the print to essentially perfectly skip over multiple layers. Once the FEP finally releases, there would be multiple layers missing, resulting in a very gloppy thick layer, or the remaining layers printing directly on the FEP.

I can’t think of any situation a loose FEP could result in the above image without at the very least one “extremely large” layer.

Not to mention, the FEP wouldn’t suddenly tighten, meaning you’d have the same issue over and over.

[–] [email protected] 1 points 11 months ago (1 children)

Suction cupping could be a possibility on the sphere, it does not explain why I had ridges on miniature prints.

[–] [email protected] 1 points 11 months ago* (last edited 11 months ago)

A loose FEP film can explain the ridges, which would exacerbate the ability for a part to suction cup like that. I mentioned that, as they're interrelated.

[–] [email protected] 2 points 11 months ago

I generally have my lift set to 7mm, which should be enough. If it continues even if I don't pause the print, I'll give it a try.

[–] [email protected] 5 points 11 months ago (1 children)

Does the preview have the ridge?

[–] [email protected] 2 points 11 months ago

The preview does not have a ridge, nor was there one when I was supporting and slicing.

[–] [email protected] 4 points 11 months ago

I should add that I'm using rafts and lifting the prints 5mm.

[–] [email protected] 3 points 11 months ago

So pausing the print appears to be the issue. I printed 3 minis today without pausing, and they all came out perfectly.

Thank you for all the responses!

[–] [email protected] 3 points 11 months ago (1 children)

I had this issue on an fdm printer when the z axis was binding up. Bumping might do it too. But since you said you paused, I’m guessing that’s the culprit, not sure why though, maybe resume doesn’t take zoffset into account or something, maybe a bug.

[–] [email protected] 1 points 11 months ago

I'm hoping that's the issue. I'll find out tomorrow, and if not then I'll look into the z axis.

[–] [email protected] 2 points 11 months ago (1 children)

That ridge looks like it’s part of the model. Can you confirm its not supposed to be there?

[–] [email protected] 2 points 11 months ago (1 children)

It's not supposed to be there, there was no ridge when I was supporting and slicing.

[–] [email protected] 2 points 11 months ago

If it's in the same spot every time, it's very likely something wrong with the model. It's inexplicable when this happens, but it does sometimes. Could try a different sd card, doubt that will make a difference, but you never know.

To me, it looks too uniform and consistent to be something with the printer.

[–] [email protected] 1 points 11 months ago

I have no real solution, but what if you make a sphere with a pre-made indent on it, so you can still pause it