I really hope you can help me! I am a goldsmith and often print with 25 microns when i need very fine details! The ring i post is not one of them where i needed the details, but it shows perfectly what problem i sometimes have. This only happens with 25 microns and not with 50 (0,05). When you look closely you also see, that the supports broke away. I use castable V2 and never used another resin so far! The Tank is clean and the resin too and there is no fog on the tank and also no dust on the glass or the mirror.
What’s happening is this: the two sides of the ring are splaying out slightly as it peels, resulting in tearing of that first support tip. If you add a support further down to prevent the circle from opening up as it peels.
Brown is your geometry. Green is it stretched during peel, causing tearing. Because 25 µm layers are so thin, the thin partial support isn’t enough to hold whereas the 50 µm version is. I’m suggesting adding the magenta supports.
Thank you very, very much. Now i understand! So from now on i will try with a little bit more supports and also more from the middle on! I will also play with a bit thicker ones!
@cfrank78, your supports look ample. I also do jewelry printing, and run very small supports, maybe as small as 0.3mm (but I do a lot of testing with this…wouldn’t recommend it for everyone!). So I wouldn’t necessarily go too thick. I also only print now at 0.50mm, finding it much smoother than 25mm (go figure!!). You might even be able to eliminate a few of the supports at the top if they are hard to remove.
@BenFrantzDale, thank you for the explanation and lovely technical drawing! I’ve never seen this problem, but know something new to avoid.
@cfrank78, do you go through the slicer in PreForm? I’m finding that I watch for the “floating islands”, and adjust the supports to make sure there are no islands. Most of my designs are more delicate than this ring, so that may present a different scenario. But in practice, I’m able to get away with many fewer and smaller supports than PreForm suggests, which for me is less cleanup. (I can tell that your supports are created in your jewelry software, or at least I’m guessing that’s the case).
That said, I do use PreForm’s automatic supports for some things, and it is a great little program. For most of my jewelry, I’m now manually adding supports so I have control over cleanup, and recently have had no failures (since those early experimentation days). I’m pleased that Formlabs added 0.30mm supports as an option.
I also print a lot of jewelry, but these problems were new to me. Yes i allways use the slicer but you are the first who said i shall use smaller supports instead of thicker ones I often print class rings and do very fine detailes art mesh sculpts. some are so fine, that i even use grey resin, which gives even superior details over castable. in the grey resin you get with 0,025 mm much more details than in the castable V2. Using then this with a silicone form is for now my workflow when i really need best possible details! Yesterday i printed some rings with these details and this who “broke” was only one that was on the same plattform!
Thanks for all your help. I reprinted the piece today with 0,025 and it came out perfectly. I will try with smaller supports next time! Thanks Ben and Kat!
Very cool, @cfrank78! And good to know about the gray resin. I’m doing direct prints right now, but had considered printing in clear or even castable v2 and making RTV molds from those. I have a wax injector, but am not doing production yet (my thought was just to prototype, then send them out for casting…or better yet, design from ZBrush on a Caribbean island, then upload the model to a casting house!)
I do push the limits on tiny supports! Over the summer I got them down to 0.20mm because I was so afraid of cleaning them up. I found a spec that said the laser size was 0.14mm, so I just sized up from there. I’ve settled on 0.30 as being a good compromise, and they’re easy to remove. But if I’m supporting something from the bottom with a support, I’ll bump them up a little.
Are you using a vulcanized rubber system, or RTV? I’m wondering about the shrinkage factor. I haven’t gotten that far yet! I had read 3% in one source, but was getting ready to make my first molds. Ah, experimentation.
I use silicone rubber molds which can be baught by a local supplier. Forget about shrinkage. Sometimes you have, sometimes you dont. Sometimes it is 1,5% sometimes its 3. Sometimes you have it in the plasticast form sometimes you dont, depends on how massive the cast ist. A hammer and a sharp tools for stone setting and the shrinkage is balanced 10 times faster than you can do it in the 3d program :-). At least this is my experience!
About supports: i allways cut them off with a pair of pliers as close as possible to the model and most times i also use them for casting. then after the cast i also use a pair of pliers and then i use a very rough rubber for my hanging drilling machine (sorry dont know the english word :-). With this the supports are removed in 0 time!
What do you suggest i shall do and could you explain it why it is not happening with 50 microns?
