Fused Prongs and Closed Holes

Please find the images of the pendant attached herewith along with the STL file.

The problem I have is that the prongs are being fused together and also the holes are filled. If you look at the center of the pendant, when illuminated, you can notice that almost all holes are filled and the space between prongs is non-existent.

The prongs and holes are at least 0.6 mm in diameter.

Link to STL Files:

What’s the orientation that you are printing?
Sometimes I have this problem with my prints, try printing more vertically, usually I use a 20 degree angle on the part.

try to oversize the holes by about .005" up to .010". The spot size of the laser sometimes causes the holes to fuse if they are not oversized ever so slightly, especially on holes that are smaller than .035" wide.

You don’t say if you’re using a Form1 or Form2. But you might try cleaning the mirrors if Form1 or the glass if Form2. That being said, small features like holes don’t always clean out with a gentle soak in IPA. I have a can of compressed air I use to blow out holes and blow off sharp creases or crevices that can still retain resin after washing, before I put the part in post cure. Small holes tend to be the biggest problem. Agitating the IPA during wash can help, but isn’t always enough…

@Leonardo_Tuorto I initially printer without an angle which gave me much worse results. I then angled it to 35 degrees which was better but still with little problems.

@areffelt Interesting. Considering that there are so many holes, I am sure increasing the hole size will have a considerable impact on the overall weight of the model. I will try and let you know.

@Randy_Cohen I am using a Form 2 and yes I have cleaned the mirrors. I contacted Formlabs support as well and they said the model has one too many “too small features” to print. I have been using an Ultrasonic Cleaner with IPA. But, as you said, it doesn’t cut it. I have an electric air pump and I think I will have to blow through the holes right after IPA wash.

Thanks all for your help.

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Just took a look at the stl and boy are there small features on that!

Recommendation: Use a small layer thickness and use a lot of supports that are small point size to reduce deformation. If those little holes on each of the leaf-like features are filling in, the slightly increased hole size should help. Try to print at ~35 deg like you were.

Best of luck to you, that looks really tough.

I uploaded my best shot at a print of that using .5mm height castable to here:

It’s in .7z compressed format in the interest of size reduction. you need a program called 7-zip to extract the .form file if you don’t have it.

I really appreciate your time on this. Thank you @areffelt. I will try printing the form file that you had given.


I hope it works out for you!

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It’s always useful to do a test print with different sized holes/prongs to see which ones actually work. This is especially true if you are working near the limits of the machine.

@billb You are right. I am working on finding out what the limits of the machine are. Most of the files I receive are from customers as STL files. So, I won’t be able to make changes to the holes/prongs. I will find out the minimum features that my machine can support and will print only those.