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Form 3 Loud Clicking sounds

Can someone have a listen to these two sounds from my printer and help me identify their source?



They happened a few times during a print overnight, at intervals anywhere from maybe 15-40 minutes apart. I’ve never heard my printer make noises like this before. It was the first time I ever printed in Elastic 50A, and the first time I’ve used a v2.1 tank. Both were brand new, fresh out of the shrink wrap. I’m running up-to-date firmware 1.11.7 and Preform 3.15.1.

#1 is a ratcheting-like sound that feels kind of like a motor trying move something past its stop. Is it mixer-related?

Is #2 also mechanical, or is that my parts snapping away from the tank during a peel? It sounds a lot like the sound @Vertual recorded here.

The clicking come from the the magnets in the LPU disengage from the mixer. This has been reported for some months, and Formlabs have offered no solutions.

Hey @rkagerer!

Definitely reach out to support if you haven’t, they’re the experts. But I can tell you anecdotally I have a Form 3 in my living room so I have quite a bit of time listening to one, and ours makes similar ratcheting/clicking sounds and seems to be chugging right along with no issues.

The second one I’m less familiar with, but as a general rule of thumb, if the prints are still coming out well, it’s probably nothing to stress about too much.

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@rkagerer - I’ve got the exact same noise come from my Form3. This printer was purchased in December 2019 and it’s only been recently making the same noise. I have another Form3 that I purchased in September 2020 and hasn’t made the same noise (yet). Scared the poop out of me the first time I heard it and I’ve been trying to get it on video ever since, but has proved elusive. You’ve nailed that sound for me and I’d propose it’s #1, but no proof. Didn’t matter if I was printing with Tough or Flex80, it made the noise regardless but at totally random intervals and it seemed to be when the platform was retracted slightly from the tray.

Let me know what they say so that I can point to your solution.

This is the mechanism that’s used to grab the mixer. It’s basically a rotating arm that engaged the mixer magnets and i think it’s housed in the LPU.

I had this same issue a while back and it sounds awful. Sounds like the mechanism is being forced past it’s normal travel or something.

I found that this would go away on a power cycle, but seemed to eventually come back with a specific tank. Since replacing the tank I haven’t had any issues…I didn’t do thorough testing, so really don’t know exactly in what’s going on.

Would your new tank be a V2.1? - Not that I understand why the tank should make any difference to the noises.

The one that’s doing it for me is a v2.1 tank. It’s the only v2.1 tank I’ve used so far. In my case, it didn’t go away on a power cycle.

Not sure if mine was a V2.1, it was a while back so possibly not.

Strange - let us know what support tells you @rkagerer! I think they offered to replace my LPU at the time, but it seems to have gone away for now.

Here’s what they said:

It sounds like the clicking noise you are hearing is an issue with the mixer coupler. This is the component that reaches up to grab the magnets on the mixer to drag it across the tank. We find that some printers will overextend the couplers and cause them to make this clicking noise. We have a way to resolve this in-field by having one of our technicians remote into the printer to apply a calibration fix.

I’m going to let them apply the fix, as soon as I confirm a few things (i.e. that it accounts for both noises, that it won’t make anything worse for other tanks, and whether there’s a way to do the field calibration locally instead of via the cloud).

I think @CarsonB1986 had a similar fix done and it helped (although he mentioned some less prominent clicking returned again later).

If I get a chance beforehand I might run a quick test print in a different tank, that I’ve used before, to confirm whether the sounds seem to be limited to this one.

Ah interesting - glad to know they might have a fix for you though!

Here’s a little update on the clicking from my machine with a short backstory. I purchased the machine in Dec 2020. It didn’t make the clicking sound when I first bought it and my first 2 materials were standard white as well as flexible 80A. Both of the resin trays at the time were V2, not V2.1. It started clicking after I had done if I remember correctly 2 firmware updates after having the printer.

In this time period I had replaced 1 tray as I had used its life up and it was still tray V2, not V2.1. So my machine has been clicking for some time.

Only recently after having tried tough 2000 where the mixing cycle is at every layer has it become prominent enough for me to want to do something about it. That is why I filed a case with Formlabs as stated in my previous post.

Also from my previous post I stated what Formlabs’ fix was for it and it fixed for a short period of time but the click came back. Talking with Formlabs more about it they call it a “cosmetic issue” meaning it shouldn’t cause a problem with the print. And to continue printing with it.

Other than them offering the “fix” of turning down the magnet, which was only a temporary fix, they have offered no other fix for it.

If you do start having print problems and you’re thinking it is the clicking then I would file a case and see what Formlabs has to say on it. Otherwise as said previously, it is ok to keep printing with it doing the clicking, it’s just annoying and will scare the crap out of you if you’re not ready for it.

Side note, my printer is still making the clicking noise and I have since printed with both V2 tanks as well as V2.1 and the tank doesn’t matter, and it doesn’t seem to me that the resin matters either. It does it with all 3 of my main materials, tough 2000, white, and Flexible 80A.

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Interesting, thanks for that update @CarsonB1986.

I went back and did a print on a different tank, and the clicking wasn’t present. So in my case, it does seem to relate (at least in part) to the tank.

Support said “the mixer coupler is overextending and is causing the magnets to rapidly reverse polarity”. But… years of Star Trek taught me reversing polarity solves just about anything.

My 3 just started clicking; It looks like the mixer moves up then a hard DOWN.
Using FL Clear resin.

Clicking stopped after the first 10 layers.


Here’s another update for you. Recently I had been printing in nothing but flexible 80A. I’ve been printing tires for my scale model business. After getting caught up on tires I started printing in tough 2000 again.

As such my mixer bar wasn’t clicking at all while printing in flexible 80A. After starting printing in tough 2000 again it only clicked once on the first print then quit.

Now that I’ve been printing more in tough 2000 and they’ve been consecutive prints, it has started clicking more often again rather than clicking once and then quitting.


I am SOOO glad that you filmed that sound because I must have hauled ass across the house a dozen times and it would always stop as soon as I got close enough to catch it on film.

Our form 3, now 1 week old, is doing the same thing once or twice with every print (tough 2K) Il submit a support ticket just so there is a record of it. thanks for posting this!!
(sounds a LOT like this)

The last firmware update:
1.14.7. August 16, 2021, for the Form 3 & 3B includes:

  • Added mixer recalibration wizard
  • Improved tank detection
  • Improved cartridge detection
  • Improved tank lifetime display
  • Improved print reliability
  • Various bug fixes|

The mixer recalibration works pretty well, I now only get a burst of the chattering once a build when the printing is starting.

The click sound is now also by my printer since the last firmware update 1.14.7
When I go back to firmware 1.13 than the noise is away.
The problem is the 1.14.7
Why is this??

If this is after recalibrating the mixer, I was talk to Support.

hello, the recalibrating changed nothing…click noise after preparing the tank