Occasional hissing noise at start of layer (I think it's every 4 layers)

Has anyone else heard an occasional hissing noise at the start of a layer?

I’m on my 5th print now, and just noticed this - I don’t remember hearing it for the first two prints.

It’s sounds a lot like the hiss from the boiler on my espresso machine that occurs every now and then while it’s idling keeping the boiler hot - only it’s quieter.

Anyone else notice this noise? It only happens once every 4 layers (I think), and lasts about maybe 8 seconds or so just after the laser starts on a new layer. What worries me is that I didn’t notice it on my first two prints …

Yep. I get it as well. Things work so I haven’t worried!

Yep, it hisses a little. Its nice to know my hearing hasn’t gone yet. :slight_smile:
I think its just catching its breath after working so hard. Those little printing elves just don’t know when to stop. :slight_smile:

So my printer has now stopped hissing - and all my prints have started failing - including prints that used to work. Both grey and clear resin with two different tanks. failures have become progressively worse with parts initially failing halfway in with the fault-line type splits shown in many other pictures - but now I just get forlorn support stumps.

I was still curious about what caused the hissing noise even after it proved to be normal - and now I’m much more curious.

I already have an outstanding ticket for a separate issue with bad galvos distorting prints that I’m going to return the printer for - but I was trying to get one last crucial print done with scale adjustments built into the models to counteract the galvo part distortion - before sending it in - but that looks very unlikely now.

Can anyone tell us what the hissing was about??


I had this kind of noise, would describe it as “high frequency whining noise” - every 4th layer of the print.

It comes from the stepper motor of the Z-axis.

To release some (possible) pressure of the stepper motor - at an UNPLUGGED Form1, you can move the arm with the build platform up and down.

(I managed it only to move up a few mm, not down)

The success was - hmm. On the next print after this, the noise was away - but the print failed (nothing adhered to platform). The print after this was ok - but the noise was there back again.

In any way - formlabs support can help you and walk through it with you.

Hi Kevin

I have noticed the same high frequency noise particularly the first few layers of a build I guessed that this noise is a result of the laser operating at a higher power than it likes? Possibly a strategy for getting greater depth of cure and better adherence to the build plate. I’ve not notice or rather not counted if the noise reoccurs every 4 layers?