Loud fan noise upon start up - is this normal?  

RE: Loud fan noise upon start up - is this normal?

I'm not sure how to parse that response. The fan makes no noise when I turn the printer on, only during print, and only for a while after the fan starts (second layer). I can't tell now if this happened more or less during the first prints with this printer.

-Lars

RE: Loud fan noise upon start up - is this normal?

Hi, 

You need to check for filament strings in the fan unit. In absence of obstruction you might consider having a spare on hand. If the printer is under guarantee make a video and contact tech support. 

RE: Loud fan noise upon start up - is this normal?

i think i have a very similar issue on the front fan, the angled one (mk3s). I unscrewed it, opened the casing with a flathead screwdriver and carefully put a drop of sewing machine oil (blade oil) behind the fan blades so it would reach the spindle. I then put it together and screwed it back into place but not tightening the screws too much. I also gave it a little squeeze to make sure the fan was seated properly on the spidle, not sure if this did anything. But something worked, its now perfect and silent like brand new.

Both these were suggestions from earlier, I'd just like to point out that it was the front angled fan that was my issue (mk3s) not the side one. If you peel back the sticker on the back there is a circuit board, probably not a good idea to put oil here. You need to put the oil in from the front on this fan. Good luck!

RE: Loud fan noise upon start up - is this normal?

@pizzatower Thank you for the clear advice. I tried the same thing (overtightening one screw in the process, alas). On my fan, the fan blades and center pieces were one combined pieces of plastic, so it was difficult to make sure the oil reached the spindle. If it did, that didn't solve my problem, it's still quite loud at the outset. 

-Lars 

RE: Loud fan noise upon start up - is this normal?

I had a similar noise on the radial cooling fan on my Mini. I peeled the Prusa sticker back halfway to expose the spindle shaft, and took a tiny blob of the included lubricant on the end of a toothpick and gently pushed it down on the spindle, then used the menu to turn the fan on half speed and held it horizontally so the grease would work its way in. It's been quiet ever since. Sewing machine oil would likely be easier, just a drop at the end of the spindle and it should pull into the bearing without the need of gentle persuasion like the grease. Put the sticker back down, and done. It SHOULD be about the same for the heatsink fan, the sticker should be on the inside facing the heatsink. 

RE: Loud fan noise upon start up - is this normal?

Thanks! A little oil fixed mine at least for now. When you replace the fan, do you re-run all the wires or just solder old wires to the new fan? Re-running the wires looks like a bigger effort with some disassembly of the x-axis. 

RE: Loud fan noise upon start up - is this normal?

wires age and fatigue with repeated flexing... I would change the whole fan and wire...

If the fan was good and the wiring intermittent, I would change the wires to keep the  printer going, whilst I ordered a new fan with wires

regards Joan

RE:

In my experience the wires go before the Fan, especially if the fan itself gets cleaned and oiled when doing regular maintenance. This to me is a drop of oil and a fin cleaning with a q-tip soaked with IPA. the wires tend to get the brunt of the wear, I normally replace them on my used fans with a more flexible wire type for replacement/ reuse of the fan upon the next failure.  The timing of this post is apropos, as I just had a fan error on one of my oldest machines last night. Two fans in 5+ years. 🤣 🤪

There are a coupe other things you can do to speed this up in the future, e.g. changing to clips for faster less invasive fan changes.

You still have to work a bit, depending on if its the fan or the wire gone bad, however it reduces the time a reasonable amount. I normally keep 4 spares around for 3 printers regardless.

Hope this helps.

Swiss_Cheese

RE: Loud fan noise upon start up - is this normal?

That sounds quieter than mine.  I'd always assumed that the fan spinning up on power-on was because it took a second for the software to initialize and make sure it wasn't turned on.

But now it occasionally gets loud for a while during a print, too.  That definitely wasn't happening before.  I guess I'll add a replacement fan the next time I order a batch of Prusament.

RE: Loud fan noise upon start up - is this normal?

I just make it a habit to blow out the fans occasionally with canned air.

I did have to replace a fan once, maybe two years ago.  The fan would start, but the tach was not reporting speed to the controller and it was generating an error.

Now, one little fan anecdote, particularly for those who think that the fans might not be important for good prints.

I had a very frustrating issue with my other printer (not Prusa, but Ultimaker) where small round prints were fine, but anything flat would consistently fail.  This even stumped a few of the gurus on the Ultimaker equivalent of this forum, until one of the Ultimaker 'smart guys' recognized the issue, which he had seen before.

One of the wires on the print head fan had broken.  (Note the free end of the black wire.)  I had neglected to check to be sure that the fan was indeed spinning (it was not).

RE: Loud fan noise upon start up - is this normal?

Some fans make a bit of noise when they start, especially if they are subjected to a sudden voltage change. This is generally normal and might not be a cause for concern.