I have the following part that contains a throgh hole from top to bottom. I would really love to NOT have to rotate this part as I want the base to sit flat on the build plate. The software is showing cupping but This is a through hole. Should I be concerned? Its a reletivly small through hole. 3/8 in diameter.
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It will survive, once you carry years of experience you can get rid of tons of supports, put parts directly on the platform and get great results.
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You make it also sound like I would not need supports for this ? is that true?
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I would definitely try to print this component completely without support structures first. There are no extreme overhangs (as you can see from the component) and the component slowly builds on itself.
A flexible platform would be an advantage here and I would push the part a little more towards the center, but otherwise I see no reason not to try it without supports first.
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Ok Thanks! Yea this prints with ZERO support on an FDM printer so I was curious why it would need support on this. Im very new to SLA printing.
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Yeah the slicers like to lean towards caution on supporting, those kind of issues can also be very printer specific so what might cause problems on one printer could be completely doable on another. If you haven’t yet I would advise trying to find a torture test print either on thingiverse or elsewhere that is clearly labeled. They are designed to pretty much guarantee a failure on certain parts but it gives you a good idea of what your printer can handle and are good benchmarks for when you fiddle with settings.
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Hey @jpuzzo,
That part should print fine without supports, especially since the through-hole is small and not near any particularly thin walls. That said, PreForm flags cupping for a reason—trapped suction and negative pressure can degrade surface quality or dimensional accuracy, even on a successful print. It might not fail outright, but it’s not best practice for aesthetics or dimensional consistency in that area.
One trick we use in CAD when printing parts like this flat on the build platform is to add a small ventilation channel from the through-hole to the outside of the part along the bottom surface. You can just extrude a tiny hole (usually 2–3 mm in diameter) from the base to intersect with the vertical hole. That way, resin doesn’t get trapped and can equalize pressure during the print. For some higher-viscosity materials, you might need a slightly larger hole. I’ve attached an example here for reference.
As for supports, I’ve found that PreForm tends to be a little conservative, but I’ve personally had plenty of success printing parts like this flat on the platform with no supports, even if there are some small red areas. Not something I’d officially recommend with the Formlabs hat on, but… unofficially, you’re probably safe without supports here.
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Thanks appreciate the insight. So currently I own a Bambu H2D and two X1 Carbons. I have always used FDM printing but am contemplating getting a Form4 so I can produce an auger ( of which this is one slice of it ). Idea is I can stack these auger segments to make up a full auger.
I have been able to print my entire auger in one go on my Bambus but the issue is the layer height. My auger is going to be used to propel ice that will be consumed. I know Form does not currently offer “food safe” plasics just yet, but I think it may be a step in the right direction to use SLA vs FDM.
Would be a huge win if I could print a bunch of these augers with a Form, I think only issue is going to be cost. SLA Resin is much more expensive.
Follow up question… the “hollow” feature… it successfully hollows it out but then complains about cupping. Is a vent hole required when you use the hollow feature? Has anyone tried this?
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@henryqiu I did what you suggested and added vent hole but when I hollow using the hollow feature it does this: Where the vent hole helps with the cupping from center… but then causes a cupping issue with the hollow object.
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I guess I could hollow it in onshape instead and add a manual additional vent hole 
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Preform allows you to hollow and add vent holes, so you should be able to do it all within Preform (it didn’t use to be like this 
)
You can probably get away with one vent hole if you placed the first one a bit higher such that it cuts through both the hollow internals and the through hole you had in the center.
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Well making it hollow changes the whole story, but as it has been said by @leonhart88 you can add ventholes now in preform which is extremely useful.
It seems like you got it sorted out but yes you will always need a vent hole for hollow parts. Not only for the cupping to to drain the uncured resin trapped inside during post processing.
Thanks Everyone I really appreciate the help on this! I did not see any option to add ventholes in preform But figured its easy enough to do in my CAD software.
Reason I made it hollow was to save on material cost. Will be curious to see how strong it remains in this hollow state.
Apologies, I had missed this. It seems you already figured it out in CAD, but if you’re doing it in PreForm, you would want to change the order of your operations from “Drilling Hole>Hollowing” (if you are using the preform hollowing feature" to “Hollowing>Drilling Hole”. This way, the boolean operation is done to the entire model and should go through both the hollowed shell and the inner pocket. If you can DM me the model I’d be happy to play around with it as well, and report my findings, as this would be great user-experience feedback for the hollowing and drilling hole features.
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