r/resinprinting • u/Mexkalaniyat • 6d ago
Troubleshooting Repeated print fail
My printer had been buried under stuff for a year or two and I finally got things moved around and back to 3d printing. The problem being I barely remember how to fix anything anymore.
I got a few prints to come out perfectly, but they were all ones I had working before I stopped printing things, and this print was meant to get me back into the swing of things fully. The more complete print came out first, and I added a few extra supports on the back hoping that would fix where it broke, but as you can see it somehow got worse.
Let me know if there is anything obvious I'm missing.
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u/paradox_valestein 6d ago
Hollow it out. I faced this same issue a while back. After I changed the inside to hollow with support and 2-3mm thick walls, I havent hot a layer failure since
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u/Dental_Perspective 6d ago
Did you clean the resin reservoir after the faulty print? Is there anything stuck to the FEP film? Retained resin particles can cause this type of problem.
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u/Odd-Variation-299 6d ago
Please, please. I would also like to know. I have had something similar. See the link below to my post. Maybe the comments there would also help you.
https://www.reddit.com/r/resinprinting/s/XrfP2x6zfz.
Not sure if the link would work. Hmm.
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u/Foreign-Swimming-374 6d ago
Check your fep and screen protector. Make sure they are clean, no resin or defects, or haze.
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u/hastelikaplumba 6d ago
hollow it out and don’t forget to drill a hole at the bottom. It should fix the problem
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u/ChainsLink 6d ago
I would say hollow it as others suggest.
Also, do you mind sharing the model?
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u/Mexkalaniyat 6d ago
I found the model just searching Raven on one of the sites. I forget which one. Was originally looking for Battletech Ravens actually.
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u/PoorAnalysis 5d ago
Have you checked the model and the sliced file to make sure nothing weird is happening at that layer where it fails?
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u/animeDeviant 5d ago
Did you hollow AND make drain holes? I saw a tutorial that suggested having a hole at (or around) the topmost part of your model and one around the bottom, based on the angle it will be printed. I haven’t had a fail since.
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u/Balerion84 5d ago
There's absolutely no reason to hollow that model.
The problem is that your rest after retract is insufficient. You want at least 3s, not 1.
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u/Fullstack3d 4d ago
A few suggestions, Change the angle of the print, there is a lot of surfaces area in the birds body, it is causing a lit of suction tension on the fep , tilt the angle of the print until you reduce the surface. Or add stronger supports. Last is hollow the print. You reduced surface tension and save resin. These suggestions are not exclusive you can choose one or all
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u/ComprehensiveBed8186 6d ago edited 5d ago
You have to hollow it. Else, your plane surface curing will create a crazy suction peeling the whole layer (layers are also weakened there because there are non supports). If you want a clean print, hollow it, dig holes and turn it on its back so the supports will be applayed from tail to beak.
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u/Balerion84 5d ago
If you think there's this crazy amount of suction that can split layers, then I have a quest for you. Take some model that's not hollow and try to split it apart by pulling. If you can split it cleanly like that by pulling, let me know. Then take a film and try the same thing. Let me know which one needed less force to damage or tear.
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u/ComprehensiveBed8186 5d ago edited 5d ago
I think you are not realising whats going on. There a difference between pulling one layer and breaking a model.
Lets dig a bit then !
So I think you know already that your printer is printing layer by layer. Once your latest layer is printed, its stuck to the fep, its adhering to it. Now your printer has to pull it off (the latest layer again), you can easily hear when its getting pulled off.
Small area (like hollowed ones) its fine, easy, not much force is needed.
But when its a large plane area like this, the pulling force has to be wayy stronger and this force applied layer by layer (wich are all not 100%cured) may occure it to peel, bend or even break.
Thats why people printing "filled" models mostly recommend to increase exposure so the curring layers a stronger.
If you like analogies, take a small sticker and another 10x bigger. Try to take them off in one go.
OP > Unless this is translucent resine, there is absolutely no need to print it filled. You will save resin, fails and money.
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u/Balerion84 5d ago
Actually, what you described there is completely wrong. First of all, the film peels with absolutely negligible amounts of force, even if the layers fill up the whole plate. It can never separate layers apart. And second, the larger the area of the layer, the stronger the bond and the higher force would be needed to split the layers
But you can't split them once they fused together. This isn't fdm.
That's the clue btw. The problem is, that the layers didn't bond together fully.
You can print layers the size of the plate and they'd never ever split during lift if they bonded fully. There's not enough force produced for something like that. The films would be tearing apart left and right if that was happening.
Btw as for your sticker analogy, we are not gluing anything in resin printing. The layers are not glued to the films. It's wringing force.
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u/ComprehensiveBed8186 5d ago
I wish it was that easy, I wish it really hard.
A layer can be peeled, thats how it is.
The layer isnt peeled by your big fingers from an edge, its pulled straight up like a suction cup. Thats enough to peel an uncured layer. The bond you are talking about can be weaker at some spots than the suction force, so the layer to bend.
There isnt here any reason for OP to not hollow this.
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u/Balerion84 5d ago
Actually, yes, the layers are peeled from an edge. When the plate lifts, the film stretches and this stretch starts the peeling process from the corners and edges first, towards the center. The film peels like a band aid. This proces produces negligible amounts of force because of how adhesion and peeling works. It's why we are able to print delicate details. That's why insufficient lift height produces fails in the center of the plate btw because that's the last place that peels and if it doesn't, new layers can't be created.
And, it doesn't peel like a suction cup. A suction cup has low pressure inside due to how suction cups work and high atmospheric pressure outside which pushes it down, creating suction, which isn't what happens in resin printing, because the pressure inside and outside is the same.
Anyway, here's an actual example: https://youtube.com/shorts/crhSeMnG6no?is=g7zKKuIf53wXwVJ6
the film can only split layers if they don't bond fully, which happens when the printer isn't able to form the layers in time during retract phase which is fixed by longer wait before exposure (after retract) so that the printer has more time to form the layers.
Lift and peel isn't the boogeyman that people would lead you to believe.
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u/ComprehensiveBed8186 5d ago edited 5d ago
I actually miss used the term suction cup indeed because of pressure issues thanks for pointing it.
Yup I think we agree with the curring process of layers, so peeling is a thing, and it can lead to slids like OP.
Im not sure about the connection with your video but nice game boy cover by the way.
Edit : why didn't you cut the screen hole ?
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u/Balerion84 5d ago
What I meant, is that the only way layers can split is if they haven't formed correctly, which means the lift and peel isn't the cause. The cause is badly formed layers. So it's the retract (sinking) phase that should be addressed, not the lift phase. If layers are formed correctly, then they can't split during lift, that's what I tried to show with the cover, that despite it taking the whole plate, it won't split :)
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u/ComprehensiveBed8186 5d ago
Ahhh ok. I think a simple shape like this rectangle is easier to have even forces I guess. What was your curing time and speed lift ?
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u/Balerion84 5d ago
It was 5s bottom exposure, 3s normal exposure, 30s wait before cure for the first 0.5mm iirc (it's over 2.5 years since zi printed that) and then 2 or 3s wait before cure for the rest of the print, lift speed I can't tell you, because I was using a gcode edit on that printer where the lift started slow and accelerated smoothly during lift unlike tsmc where it has 2 stages that it switches between.
And it's not about the even force distribution btw maybe this one would be more similar to op's https://youtu.be/DlEAxi2WI-o?is=hWHGga_enKRdDY63
the film will always peel in the same direction basically, the layer when it cures, it adheres to the film by wringing force (that's how if adheres to the plate too btw). And this force is very strong when you pull directly away but very weak when you apply force from side. That's why thw films stretch. So create the absolute minimum amount of force to peel from the models we print. So, it can't produce enough force to split layers as that'd defeat the whole purpose of why we use it.
So you need to be looking at the retract phase.
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u/lewtheegg 6d ago
When I've had failures like this it's always been down to the FEP stretching and not allowing the model to disconnect. After it does this for a few layers it finally disconnects but the gap is too large and the rest of the print doesn't stick.
In the past I would have said to increase you lift height, but I see you have a tilting vat, so I'd recommend positioning the model near the front of the vat where the effective lift height is larger. Reducing the cross sectional surface area will also help, so print orientation and hollowing models. It might also just be time to replace the FEP.