Failed Prints - Hazy, blotchy marks on optical window

Hey everyone, I’ve recently had some failed prints and I’m in the process of troubleshooting with the third party company I bought the Form 2 through here in the UK.

My Form 2 is only 1 month old and I have used 1L of standard grey resin so far. This week my prints have been failing.

After removing the tank I noticed some streaky/ blotchy / hazy looking marks on the optical window. Has anyone else experienced this? Any ideas on what could be the cause? There has been no resin spillage and I have only just removed the tank for the first time to discover these marks.

Anyway, just thought it would be helpful to share this here so Formlabs can work to avoid issues like this in the future.

Thanks! Beth

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Thanks for sending this over - hazing like this shouldn’t be your expectation and could certainly be contributing to the print errors you’re seeing. We did see an effect like this on a small batch of mirrors, and I’ve forwarded this to our manufacturing team so that we can ensure that it’s been resolved.

Do you have a ticket open with our support team? Oftentimes, this is corrected by a swap of that glass panel and hopefully we’re able to get you up and running again quickly!

Thanks for getting back to me. As I purchased the Form 2 through a supplier in the UK I have to raise the issue through them rather than formlabs directly. I believe they have requested a replacement optical window from Formlabs on my behalf and I am waiting for a delivery date and instructions on how to replace.

I appreciate faults like this can happen from time to time, but it’s a bit unfortunate that I have now missed a deadline to deliver a print to a client :frowning:

Yes. Spending tonight cleaning up an almost identical situation, although my streaking is a different shape. Apart from that, and I am using black resin not grey, our stories match exactly!!

@wunwinglow Sorry to hear you have also had the same problem. We must have had a faulty batch of mirrors. I was advised not to clean the underside of the mirror as it could possibly leave dust speckles, therefore I am having to replace the mirror altogether.

If these are indeed a faulty batch of mirrors then I would assume the same issue would happen to the mirror again even after the cleaning. Replacing for a new one might be a better option for you as well perhaps!

@Beth , I have streaks on the inside of the window that is directly under the resin tank, the one the laser shines through to cure the resin, and dust on the 45 degree mirror below, so I am hoping the sort both out this evening. This is after replacing the cartridge floor as I was getting loads of cartridge removed errors, so I am getting to know the inside of my printer quite well already, and I’ve only had it for 3 months!!

I’ll let you know how I get on…

I meant to say ‘window’ not mirror, it sounds like we had the same issue with the window. I hope I don’t have any problems with the 45 degree mirror as well. Good luck with your repair work!

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Hi Beth, I’ve got the same problem, all running fine until a week ago, I changed the glass and still cannot print, tried everything so far. Did you update the preform software recently? I think it’s something to do with the update. I’m in the uk too and am trying to get the printer sent back. Let me know how you get on with the new glass, ian .

Hey Ian, sorry to hear this has happened to you as well. I haven’t updated the preform software as I know some people have been having issues, so I purposely avoided doing this.

I was sent a new optical window, but it wasn’t 100% clean (had smudges and flecks of dust). I tried replacing it anyway and tried a test print but it still failed. I haven’t been able to print for two weeks now, which is having an affect on my business.

I don’t understand why Formlabs don’t replace the printer with a new one straight away, especially a 1 month old printer. This is what would happen with any other product from companies like Apple, Samsung etc. Especially since it’s a fault with the printer itself, and completely out of the user’s control.

I hope they resolve your issue as well. Did you buy direct from Formlabs or a Uk supplier?

  • Beth

This is the new replacement window I received. Definitely not clean! :see_no_evil:

… and here is a selection of some of the failed prints. (So much resin wasted :persevere:)

Hi Beth , I purchased through goprint3d they sent me out a new window, much cleaner than yours!! That looks terrible! They are trying to help but everything I try doesn’t work and the same here, 2 weeks now without a print. I’m now waiting for formlabs to respond as to the next step. I’ve just ran out of resin too, pains me to buy more for test prints that fail! Ian

Sorry, just looked at your prints, my printer won’t even do that, just prints a smudge in the tray


This was my last print before it all stopped

I got mine through goprint3d as well. How old is your printer? Mine is only 1 month old.

They are sending me second window now. Hopefully this one will be clean and I can print again. If not I suspect the problem is deeper and I’ll be going through the same process as you.

We should totally get a complimentary resin cartridge for all the wasted test prints!! @Formlabs do you think this is fair to ask?

I seem to have a breakthrough , its printing ! I moved the model to the corner, looks like it may be the build platform. I bought my printer in October and it has been great until 2 weeks ago. Am trying to roll back the preform software but can’t find how to on the internet .

Spoke to soon, but at least it printed something

I also have my impressions missed by 50% unfortunately the formlabs is not managing to solve these problems I have observed that the complaints in the forum has increased a lot.

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