Phenom. Not getting accurate prints

I have a Phenom that I’ve been learning how to use for a little while now. It is my first resin printer. I am trying to print molds for loss wax casting. I have worked out a hand full of problems I was having, and I am now printing small molds that are coming out nice. But now I am trying to print some larger molds, and they are not fitting together. the small molds just use small pegs to fit together and have no problem.

On the large mold there are a lot of parts that need to inter lock. All the negative interlocking parts are 0.08mm too big, which is fine. But all the protruding interlocking parts are 0.33mm to big (with a little variance) This is obviously a problem because they won’t fit together. The part flat on the table was printed at the same angle as the other part, and they where printed at the same time. I set them at the highest angle just before sports where generated on the face of the mold. My first guess is that maybe that they actually did need supports and drooped, making them too big? I’m not sure if I should just try printing them flatter, or if there is something else I need to do. I’m using ChiTuBox. Here are my settings.
I would really appreciate any help!

making parts that can interlock require extra care on the structure of the mold, since the resin will shrink about 6% after cured
The bigger the model, the bigger the effect, and the shrink direction depends on the shape of the model

I,m surprised that you would go with this printer first, it;s a fine printer and i have one but i did all my experimenting on a smaller printer, The Phenom is at it’s best when your layer height is .05 in my honest opinion. If your going to do .035 your exposure time seems high( which means more heat ) more expansion and contraction per layer. for example Peopoly Def resin at .05 is 12 sec’s exposure, Good rule, the thinner the layer the less exposure.

I make parts that have to fit tight, i don’t go right to the UV light, I let my parts set in normal light ( not sunlight ) for a day or two before I put them in the UV chamber and keep a record of cure times so i dont over cure.

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I was having problem with parts fitting together, There material shrinks to much
I switched to Poly Juice

Thank you. That is really helpful, and it makes a lot of sense that it’s getting too hot, I hadn’t thought of that. I will give that a try this week and see how it comes out.

And luck with this?..

Sorry for the lat response. I just saw your reply. I used the recommended settings from Peopoly at .05 with 15 seconds and things did come out better. (Im using Siyara Tech Blu) But holes still come out funny. I did a test with three holes. the smallest one was a little small and the biggest was a little big. I’m staring to think maybe I should try a different resin. I read that people thought this resin was really thick and different than other resins. so maybe I will have beater luck with a different resin. I didn’t notice a big difference in letting it sit for a couple days, but again I wonder if that’s the resin. Are you using Deft resin?

I have the Gray and the white, I am going to look on u-tube there was a video on this, you are able to to adjust you LCD screen size to compensate for the variances.

I did it a while back but have forgot the procedure, let me find that for you, and i would say yes it;d will be different with different resins,

Why 15 sec, recommended is 12.5 i beleive

That sounds cool. On the resin guid they recommend 15 sec for siyara tech blu. I just got some siyara tech fast, which has the same recommended settings as deft resin. But I’m still having the same problem with holes.

Most my molds need split holes like this. Its fine if they are a little off, but .01in (.25mm) out of round is too much. This is the main problem I’ve been fighting.

both Fast and Blu have flexibility and depending on how object is place, it may get distorted not by light but by other factors. You could increase the hardness by adding resins like Sculpt or Simple.

You could give Simple by Siraya Tech resin a tried. It has higher hardness than Fast and requires less support and cleans with 15% alcohol. Our Neo resin is similar but goes one step better and clean with 10% alcohol and super easy to print.

Ohhh. Okay. I do have some Sculpt. I will try mixing them. I will probably order some Simple,and give that a try as well. Thank you!