Unsupported Minima Suggestion

Hi all,

Just wanted to start off by saying I’ve been using the Form 2 printer and Preform software for almost a year now and have had a great experience using them. My question/suggestion is in regards to the most recent Preform update:

A lot of models I print for work are very small and have hard to reach places that I can’t get with the pliers to snip the supports off. As a result of the small features, I usually find that I have a bunch of unsupported minima highlighted in red when I generate the supports. I really like this feature, but I was wondering what happens if I don’t add support stems to every minima? Does the laser cure the resin in that spot even it is unsupported (resulting in floating bits in my resin tank)? Often times these are small features that don’t have room to put supports on them.

I don’t know if this is too much work to be worth it, but I thought it might be a cool and useful feature if you could choose to eliminate the unsupported minima by deleting the red highlighted areas and saving it as a new STL or OBJ file to print? I don’t know if this is even possible to do but I thought I’d throw it out there as a quick dirty fix for any file that’s a prototype print haha. That way you don’t have to edit the actual parent file to accommodate for the print job geometry supports.

Any thoughts? I’m mostly just concerned about any floating particles from the unsupported minima blocking the optical window of the resin tank.

Thanks a bunch!

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Yes, in principle. Sometimes the smallest unsupported areas are “picked up” by the next layer but i wouldn’t really count on this to work well.

If you choose to ignore unsupported minimas, I would advise to filter the resin after every print if there are lot of red in Preform, or keep an eye on it and do it at least very regularly.

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If you have something that’s really not supported then it will be printing in empty space and you’ll end up with bits of cured resin in the tank. The area that’s unsupported will continue to print that way until it reaches a point where a supported area connects with it.

It’s not that bad to have some of those bits in the tank, but the bits can stick to the rest of the print or might not come off the bottom of the tank which if it’s a lot of material will cause a print failure.

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Have you thought of cutting your model in half (or somehow slicing it into pieces) in your 3D modeler software, and then gluing the parts together with clear super glue once they’re printed? Not sure if that’s an option for you.

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Thanks for the feedback! Its not so much the overall size of the model as much as its the minute features that are scattered throughout the design. Its just for prototyping purposes so we don’t want to go through the trouble of deleting these numerous features before converting to an STL. I was just thinking it’d be a cool/useful option to be able to have Preform create an edited version of the STL where it deletes the unsupported minima that are highlighted red for quick prototype models and such.

Thank you for your response! That’s good to know. I wasn’t 100% sure but I figured that might be the case. We’ve done numerous prints like this though without any failures like that. I try to maintain the resin tank relatively well, using those rounded edge paint scrapers to make sure nothings blocking the optical window. As JohnHue suggested, I might just filter resin more often as well. I appreciate the feedback :slight_smile:

Hi John, thanks for the feedback. I usually filter the resin in the tank if we have it sit for a while, but I might just do it more often in order to avoid what you were talking about for now. Maybe I’ll find a better way to get around those pesky minima, but its the nature of the models that we print for prototypes. I’ll definitely let you guys know if I figure out a long term solution. Cheers!