Non-round parts

I am really surprised at the non-roundness of the parts I am printing.  I am printing parts in clear using .025 and using version 9.2.1 since the current release won’t run on my machine for some unknown reason.

I am printing a cylindrical part that should be .500" but when I measure the part the diameter ranges from ,498 (expected) to .516 (way too much).  This is the sort of tolerance I would expect with fused deposit printing, not Formlabs.

Anybody having a similar experience.


I believe you will need to first figure out which axis is out.  Then somehow get the newer version to run on your computer.  I would then try to adjust with the new feature to fine tune the printer.  Assuming your results are with 4% of the dimensions of the part ( without doing the math I believe they are) then the new version can fix / get you better results.  I do not think FL posts numbers guaranteeing part accuracy but based on the fact that the software can scale 4% over and undersized I believe the magic number is 4%.  Anything beyond that, I would open up a support ticket.

Unfortunately he won’t be able to use the new scaling feature without upgrading Preform to 1.2.x first.

Mark - can you provide any more detail about how the current release won’t work on your machine? I found it was a very awkard install - with the “could not open DFU device error” - but I think power cycling the Form1 fixed that - and then after the install had to do another power cycle.

If you do manage to install 1.2.1 - please let us know how you get on with the X/Y scaling in Preform>help>fine tuning.

It doesn’t do anything on my machine.

Thanks for the help. I can understand scaling up or of down but you would think it would not be so non round. I tried installing the new software but anytime I tried to open it it just crashed. I suspect it is a problem with my operating system since I am running vista. I haven’t tried to upgrade yet. Maybe that will work. I am also going to try installing windows 7 next. I had put in a support ticket and the solution was to give me the older version of the software. Thanks, Mark

Yes I was very disappointed with Form1 inaccuracy as well - given their promotional prints of working nuts and bolts, planetary gearbox and the gyrocube.

But hopefully the fine-tuning X/Y scaling will mostly solve it - although as I say it doesn’t work for me. Please let us know how you get on.

If it doesn’t work for you, and you cant to wait for FL to fix it - and, if you’re brave and prepared to void your warranty - or you’re prepared to just lie to FL  and deny you’ve opened the Form1 up next time you open a ticket; you could fix your galvo accuracy with it’s built in tuning trimpot. See my thread here on the subject :

Also here with video :

Thanks Kevin, I will let you know how I will make out. There is something off on my machine though. I am printing parts with words on the outside of the cylinder that 180 degrees apart. One side the letters are decent and the other side they are washed out. I have turned the part 90 degrees and am reprinting the parts to try and deal with the differences. I guess there is a lot to learn about my printer.

Is the washed out side the same side as the supports? if so that’s a limitation of the Form1 and the current resins - where there is some inevitable overcuring as the laser shines through the lifted surface on to uncured resin. Surfaces facing the resin tank silicone always come out better.

If good surface finish all around is important to you (I’m making dental moulds - so I just orient the mould surface to face the silicone) - you could try Monger Designs B9C/FL resin blend.

He had some great results picking out wording on parts vs standard FL resin. See here : I think it has to be far and away the longest thread on the forums!