Fighting All That Can Go Wrong With Resin

[Jan Mrázek] is on a quest to make your resin 3D prints more accurate, more functional, and less failure prone. Let’s start off with his recent post on combating resin shrinkage.

When you want a part to have a 35 mm inner diameter, you probably have pretty good reasons, and when you draw a circle in your CAD software, you want a circle to come out in the real world. Resin shrinkage can put a kink in both of these plans. [Jan] identifies three culprits: resin squeezing, resin shrinkage, and exposure bleeding. And these three factors can add up in unexpected ways, so that you’ll get a small reference cube when you print it on its own, but large reference cubes when printed as a group. [Jan]’s article comes with a test piece that’ll help you diagnose what’s going on.

And then it gets complicated! Exposure bleeding depends on your printer and the exposure, but also on the color and UV opacity of the resin. Shrinkage obviously depends on the resin chemistry, but also takes a few days to reach its final state as the print fully cures. Of course, that curing rate depends on temperature as well. [Jan] is just starting to document all the variables, but you can print out his test piece and do your own work as well – you’ll probably have to anyway because of resin-to-resin variation.

While you’re down this rabbit hole, check out [Jan]’s post on viscosity effects and elephant’s foot. If you’re plagued by odd first layers, this is a tremendous resource with one simple takehome lesson: wait longer in the beginning to allow the resin to flow in.

Whether you’re just diving into resin printing, or a seasoned pro, we have a ton of interesting resources. From this article on picking the right resin, to this on whether to use resin or FDM, you have a lot of reading to do. And that’s not even mentioning the gooey Hack Chat last fall with [Andrew Sink], where both he and the crowd dispensed much wisdom.

6 thoughts on “Fighting All That Can Go Wrong With Resin

  1. “…you’ll probably have to anyway because of resin-to-resin variation.”

    Is there any kind of industry standardization? How about quality control? Sensors and software to reduce the variability.

    1. That’s a lot of parameters. UV permissivity and viscosity at different temperatures being the big ones. Now just get the entire industry to agree on a standard set of measurement conditions…

      In the FDM world, we’re pretty much used to having to print a couple test pieces for “the same” filament, when you order it in a different color. I figure this is about the same thing.

    2. In order to have different mechanical properties for different types of resin, the resin chemistry has to change significantly. Also, every manufacturer is going to have their own recipe that’s slightly different. Standardization would either limit competition (because the companies would all be using the same recipe) or limit the types of resin (no flex resin, or castable resin, or high strength/high detail, or water washable, etc.).

      As for sensors, there’s too many variables that need to be measured and there’s no good electronic sensors that can measure things like how much resin shrinks when it polymerizes.

      The best solution is for manufacturers to keep their batches consistent, and then publish fine tuned profiles similar to what has been tried for FDM (like Prussia filament).

    3. Q: Is there any kind of industry standardization?
      A: There is will never be this, due to the fact of companies and business and such will not reveal their recipes for resins that is why there are so many out on the market of the same colors. As well, Clear takes longer to cure than black till or even grey, and certain colors will harden or be more flexible than other when curing. This is set up to the manuf of said resins, and their ingredients, if it was all standardized then everyone would be using the same chemicals to get same results cause that would be ‘ROUGHLY’ the only way to get the standardization across the board. let alone this is the USA this is a Consumerism society and they bank on the fact that we will buy as much as possible. But then again this also leads to advancements in the resins when others use different and safer across the board. trust me you want competition not stagnation.
      Q: How about quality control?
      A: This is normally all done in house with resin companies normally, but they all follow standard practices of toxicity and such and have labels and such like normal chemicals on this planet…so for the most part this is kinda mute in the sense that quality control for 1 is not the same as for another 1 in the same arena some people have different means to test and diff means to actual quality in their eyes. Akin to: beauty is in the Eye of the Beholder.
      Q: Sensors and software to reduce the variability.
      A: Good luck, unless this is done manually, ie: drip a drop in/on a sensor to tell what it is, this would be the only way to actually tell, and this as someone put out $$$$$ mondo amt of money to either make a separate addon to said apparatus, or even standalone thing. this would be akin to what… someone correct me if i am wrong, spectral topographer? And afaik these for one are pricy alone let alone getting one miniaturized to the size of a wash and cure station in this day and age… next to impossible. Let alone the software to write all of it which again is $$$$.

      All in all, maybe in about 50-100(maybe more really) years I can see all of your questions being fulfiled but right now in the next 50 years none of this will ever happen.
      We dont have the technology for any of this and till consumerism goes away which right now it wont, none of it will happen sadly.
      Even worse all what you asked, all rolls into 1 if you think about it, the standardization of quality control with resins, would be only possible with Sensors and Software, it is a endless loop really. If you need the software to write standardization for resins and such then that again is $$$ it really sucks.
      Although I agree with you on everything to make our life easier, it will never happen…not yet anyways…until we get replicators like in startrek. And it makes me sad cause i will never see this in my lifetime.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.