Form 2 Accuracy problem, shrinkage in Z-direction

Hi all,

I have a new problem with my Form 2.

I printed a model in two pieces, and after I washed them, i saw, the top of the models are smaller, then the bottoms. The first print orientation:

Because it is a precision part, I repeated the print with new orientation:

But the result was same :frowning: The printed parts are inaccurate.

The one part:

The another part:

The two sides don’t pass :frowning:

I read in the forum, that it is better, then the two pieces stay in one direction, it is ok. But this distorsion is normal? Or can I calibrate my printer?

40,4 mm should be 40 mm.

This is a Formlabs Form 2, 10 months old. I use only simple grey resin without post curing. There has never been such a problem up to now (so far I used about 4 liters, and two tanks). I bought a new resin tank and new resin, than came this issue. And there was a firmware update and PreForm software update before this.

is there any idea for someone? Thanks in advance.

Big model have the same problem:

This is an industrial part, it must be very accurate.

I have printed many precision parts like this with similar results. these machines are less accurate as the parts get larger. the bending of the support structure during printing causes slight shifts that accumulate as the part gets larger. I sometimes change the design of the part to accommodate the printer. (i know, bad idea) sometimes it works. Like the circular part you have that is to halves, could you design it as one part. I know this does not fix the printer, but I personally don’t think your going to get better results then you are showing. One thing more I would suggest is to add more supports. It’s seems that I have had better results with accuracy when the part can move less on the supports when printing. I know this is a trade-off with having more support defects on the part.

We print mostly extrusions (to eventually be PVC window & door profiles). My greatest success with respect to accuracy is building the “extrusion” straight up, in other words no tilt on X & Y axes.

To do this without destroying your resin tank you need to print using the LT tanks. I have done quite a few straight up builds in LT tanks with no apparent fogging. Form Labs probably does not recommend straight up builds but that won’t stop me…Whatever works !

Hello there! Thanks so much for taking the time to post here. Sorry to see you’re having some accuracy issues!

One important thing to confirm is whether the warping is happening before the post-processing steps(washing and curing) or after, as this shows us what to look at in terms of solving the problems.

Other folks in this thread have had some great suggestions for things to try. I would also suggest printing these parts at 100 microns(the largest layer height) as this will give you the best dimensional accuracy.

It looks like these parts are adequately supported, but under-supported areas of the print can also lead to warping as well.

As usual, or support team would be more than happy to investigate your case a little more deeply if you’d like. If you want to get in touch with us directly you can submit a support request at the link below and we’ll usually get back to you that same day.

Hi everybody,
Thank you for all the fast replyes and the helpful informations!
I measured the models after washing (supports are in the models). The printer is leveled. The glass is clear, the resin tank is almost new. I saw many times the tutorial videos (orientation, cleaning, model washing, change resin tank, etc).
The little tube (first pictures in this topic) I had to be printed in two pieces, because there will be a prototype for molding.

I printed the big part in 100 microns (I print all big models in this resolution). Recently I printed a Kraz truck model in 1:14. It was a big work, the vehicle built about precison parts. And all the pieces fit very well. The resolution was 50 microns. The resin was V3.

The earlier printed parts fit perfectly:

I would like to work with durable, castable and dental LT clear resins soon, but first I want to be sure, that the accuracy will be 100 %. In this resins 0.1 mm inaccuracy is too much.

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