Support size for Flexible resin?

I see that the default support size is much larger with flexible material (2.2mm point size). I have not used the flexible before so I was wondering if this is something normal with flexible or if I can use the same sizes as I would for the regular materials like clear and black?

I have a decent amount of experience with flexible resin and would not recommend going much smaller than the minimum recommended point size. Certainly not the same sizes as you would the standard resins…that would just set you up for failure. Density you can play around with a little, however the flex material needs a lot of support by its very nature. See this support page for more details regarding Flex.

So what density and point size is a good starting point? I have added a couple pics of the parts.

Your pieces look fairly well supported for their size/weight. They probably would print just fine. If it were me I probably would add a few more supports in spots such as these (see image below). But I’m overly cautious…like I said before it probably will print just fine.

I submitted with the standard 1mm density and 2.2mm point size for the first try. Thanks for the feedback!

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2mm point size worked well for me

What I hate mostly when using Flexible resin is the fact that removing the support marks on the print is very difficult. I followed formlabs’ workflow but still couldn’t get to make the print look flawless as with other materials.

I have just recently used the latest flexible formulation and can offer these observations:

Do not have supports on the exposed (or good side) of your print, I had evidence of the supports even after removing them as best as I could.

When removing the supports from the model, use a fresh Exacto blade or similar. You need a good sharp blade to cut them cleanly. Cut them as close to the finished surface of the model as possible.

My supports were on a flat surface (and the back side of my print), I post cured the parts after initial removal of supports and then used a freshly sharpened flat chisel to remove what remained.

It looks like you have thin, raised areas around the holes on what appears to be the face of your model…IMO, you will not be pleased with these areas once you have cut off the supports. As I noted earlier, keep your supports in areas not seen in the finished product, if possible.

Typically, I’m all for being a bit scandalous and reducing the default point size if your geometry supports it but this doesn’t usually work for flexible. Reducing to 1.8mm caused parts to detach from supports for me. Placing supports on regions where they’ll easily be cut away and then using the flush cutter tool or an x-acto blade to remove the points works well. A fun trick for making sanding a bit easier is to freeze your parts. This makes them harder and has the added advantage of producing condensation allowing you to wet sand with no additional effort.


Mind…Blown… I never thought of that with flex. I am definitely going to try that next time.

Echoing what the others have said supports on non visual areas of the parts is key and an sharp blade is extremely useful.

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freezing the part, now that is clever thinking. Ill bear that in mind when i use my recently purchased flex resin. Just need to convince the other half to be able to use the freezer.

thanks for all the insight. The parts were “successfully” printed with 2.2mm but like everyone said, I wont be happy with the look after removal. I didn’t think to freeze or to remove the supports before curing…will try next time.

I guess using flexible is really for proof of concept and to expect a flawed (bad) side of the print. Unfortunately, having a bad side isn’t always desired. I am guessing some people get creative by adding sacrificial meat to their parts, with the intentions to remove after. Any success with that?

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