How to prepare STL for preform

Good morning,

i would like to ask your help. We just started the Form2 in our hospital for testing purpose.
We scan jaws and want to print the *.stl Files with the printer.
2 times it was a failure: The model was displayed in Preform and an the printer but was not printed.
Only the automatically adjusted supports were printed.

I read here that this could be the case that the *.stl File is not a qualified solid.

Can someone describe me how i can concert the *.stl file in freecad or meshlab to a version that is qualified as a solid? I Think that this will solve the problem.

Yeah i know me and my department are rookies so would be great we can profit from your knowledge.

All the best


There are lots of reasons that this could be happening. Normally stl meshes are repaired in Preform (its quite good at that)

What material are you trying to print with?

We use the Dental SG Resin.

Have you printed other things without issue or are these the first things with the printer / resin?

Good morning,

it is the first time that we used the printer and resin, tank and so one was completly new.
Today morning i started a test with the butterfly stl givin by formlabs and was also a failure.

Do you have any other resins that you can try - Its probably best to start with a standard resin, such as clear V4 to prove the printer, and then to move onto the Dental SG.

If you have only the Dental SG resin then please try printing out the print below - Its deliberately poor in its orientation (Worst case scenario for testing), but proves both the resin and printer. Simply open the file and load as is in PreformTest coin - Dental SG.form (384.3 KB)

Please publish pictures of the results

We do not have a different resin.


Here i have Pictures of the results.

Those where you see only the supports are of the test this morning.

I dont understand this.



So, its printed the test print without issue and it looks like it built well in all 4 corners and the centre of the build area.

Can you post here the STL file and the FORM file for your print - we will see if we can see anything obvious to try and help you.

So here are the files.

I was not able to upload them direct so here is the link to download them:

(One Drive)!Au0X8K_C7SibmHQ1eKitAi-TGFQU!Au0X8K_C7SibmHN8KEJaDw5WPqWB!Au0X8K_C7SibmHJfU9P2h5x5mBhv

A question for you has to be “is Dental SG the correct resin to print retainers with”?

Dental SG needs cleaning through a filter between prints (it seems to collect a lot of bits during a print - those bits cause failure of later prints, also the pigment stays in suspension for a relatively short time before it precipitates out.

We have printed the file below (using your model) with success) As you can see the orientation is flatter, which in practice is better with this resin (supports suffer less breakage)

The link will be deleted after 24 hours

Scan data is almost never a qualified solid.

It sounds to me like you folks are not 3D modeling mavens, but more medical professionals looking to access this technology.

For that reason I strongly suggest you invest in FreeForm Modeling software from 3D systems.
Although available without a haptic arm, you really really want to spring for the haptic arm.

Ever see one of those documentaries or youtube videos of folks doing a reconstruction of a face on a computer? Or of doctors using xray scan data to print practice models of patient skulls or spines? Or prosthetic makers using a computer to model a custom orthotic?

Chance are you saw them using Freeform. Its the go to app for anyone in the medical field needing to produce solid models from scan data.

What you will like about Freeform is you do not have to be an expert in computer modeling to use it. Its learning curve is about 3 weeks. And it Can not produce a model that is not a qualified solid.

Importing scan data it will convert it to a solid- filling any holes in the data to create a solid. You can then very easily clean up the model anywhere it filled in holes to make the model correct, and even model whatever you want or alter the model in any way you can envision.

Because of its haptic interface and its voxel modeling space, you will find that anyone can quickly learn how to use the software to achieve excellent results.

Do yourself a favor, and look into Freeform. There is a reason you keep seeing it in videos of medical uses for 3D modeling.

Here’s a link to a version of one of your files that I opened in Freeform, and then exported.

It should be a qualified solid.

the units in preform need to be set to INCHES.

try printing this.

Hey Folks,

so i tried to follow all tipps but was now success. Even with the files provided by Dxxxx and Sculptingman.

I will no get in touch with the Support and will make a Troubleshooting. Very frustrating. Especially because other models are fine. Only our dental models are not working.

But thank you for your Support.

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