I think my fan is starting to fail

Hi there!

I think my fan is starting to fail...

Every 30 minutes it starts to vibrate and stall,
when I give it a small tap it speeds up again...

This also happens when I home the X-axis,
the head shakes in a pattern that triggers it.

Don't know if I can fix it by mounting it different,
I guess it's best to start thinking about replacing?

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RS-Online Ormerod #263, Kossel mini with Minitronics, Prusa i3 MK2

Poor connection in the hot end connector? Could be the fan bearings on the way out, too. If can't spin freely when off, it's probably dying. As it heats up from the effort of turning, it accelerates the failure.

Ian
RepRapPro tech support

It's seems to be the resonation of the whole rotating part.

I constantly hear it starting to buzz and become silent again,
sometimes it starts to buzz so much the whole part resonates.

So the fan bearings is probably a valid guess...

I will check if the fan spins easy when it is turned off,
this will be in about 5 hours when the job finishes

Or better yet: Tomorrow morning when it has cooled?

Edited 1 time(s). Last edit at 01/19/2014 07:56AM by 3D-ES.

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RS-Online Ormerod #263, Kossel mini with Minitronics, Prusa i3 MK2

I found that when I tighten the bolts that hold the fan, it distorts the fan housing because it is only bolted through at the bottom, and the fan blades start rubbing on the casing, either seizing the fan or making a loud noise. Slackening the bolts cures the problem, but then the heat sink is not clamped tightly to the cooling block because it is held with the same bolts. I have bought another fan that has brass mounting inserts so won't distort. Careful that you choose a fan with similar airflow - I found one that blows slightly more than the kit supplied part, but there are others of the same physical size that blow a lot less - check the specs before ordering.

I've not fitted the new fan yet - I'm printing new fan parts from ABS first so they are less likely to be bothered by the high bed temperatures I use.

Dave
(#106)

I am having a minute day of silence for the loss of my fan...

Last night I powered down the printer after printing a part,
when I switched it back on, the fan only wanted to resonate.

Tapping is no longer the miracle cure that makes it speed up...

Some info:

- My fan spins very easy when I turn it.
- I can not get the blades to touch the casing.
- It was bolted tight, but I did not see it deform.
- I *think* I see a tiny bit of grease in the casing.

@dmould: Thank you for your suggestions!

I would like to order a new one today @ RS.

Where did you find the specifications of the fan?
Or perhaps better: which fan type did you order?

I am trying to search on the forum for the word 'fan'
but it's probably too short for the search mechanism.

I hope the part number of the fan is not a trade secret...?

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RS-Online Ormerod #263, Kossel mini with Minitronics, Prusa i3 MK2

Quote
3D-ES
...I am trying to search on the forum for the word 'fan'
but it's probably too short for the search mechanism.

I hope the part number of the fan is not a trade secret...?

Try this thread - I think there is something in there and a link to a better one (at work, not much time, sorry)
[forums.reprap.org]

Erik

Why not ask RRP for a warranty replacement? Although if you are not in the UK, ordering from RS may be quicker.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thank you both for the super-fast responses!

I have ordered the one that dc42 linked to in this message

Ordering it locally is quicker, and it is a cheap part...

I don't want to bother RRP with small warranty issues.
I would rather see them focus on new development

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RS-Online Ormerod #263, Kossel mini with Minitronics, Prusa i3 MK2

I got this a lot from many different fans. If it resonates you still have a chance. Take it out. The bush/bearing will normally be covered by a sticker. Gently pull it off and add a drop of oil, making sure you don't get any on the place where the sticker goes. Put sticker back and power up again. If this does not work then it just might be stuffed ;-(

Thanks victors, I will try to fix the 'old' fan.

Disassembling Repairing stuff is one of my hobbies!

Edited 1 time(s). Last edit at 01/21/2014 05:31AM by 3D-ES.

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RS-Online Ormerod #263, Kossel mini with Minitronics, Prusa i3 MK2

Mine died too,
I replaced it with 474-5549 which is a better fan (faster, better bearing) and it is working great so far.

Chris

Hi Chris!

I have searched at RS for part # 474-5549,
this number seems to belong to a timing belt..?

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RS-Online Ormerod #263, Kossel mini with Minitronics, Prusa i3 MK2

Quote
3D-ES
Hi Chris!

I have searched at RS for part # 474-5549,
this number seems to belong to a timing belt..?

Ditto

The one I chose is 781-5048 - it doesn't have brass bushes as I had wanted, but it clamps tight and still works. Bit noisy though, so I'll search for something quieter.

Oops, picked the wrong live from the order !!

492-4332 Fan,40x40x20mm 12V 9000rpm 21.6 m3/h

A bit noisier than the orig, probably because the higher RPM but more air flow, and suposedly
high quality bearings to last 300,000 hours

Chris

Quote
chriscain
Oops, picked the wrong live from the order !!

492-4332 Fan,40x40x20mm 12V 9000rpm 21.6 m3/h

A bit noisier than the orig, probably because the higher RPM but more air flow, and suposedly
high quality bearings to last 300,000 hours

Chris

My replacement fan is a higher airflow than the original (which started rubbing and making a heck of a racket). After changing it, my extruder can only get to 245 deg (I'm printing ABS at 250) and it doesn't fuse to the previous layer quite so well - I guess because the extruded filament is cooled faster, so I have a lower power (and quieter) fan on order. So you might find the higher airflow is detrimental to your prints, though I guess PLA is more forgiving. I did think of messing about to adjust its RPM, but it's easier to just get another fan. I'll also try Ian's idea of blocking the centre outlet channel.

Dave
(#106)

I have received and installed the new fan today,
the noise level is the same, it is the right type!

Edit: One thing I would like to add:

The original fan had countersunk screw holes,
this one has not, it makes them stick out more.

Edited 1 time(s). Last edit at 01/23/2014 03:13AM by 3D-ES.

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RS-Online Ormerod #263, Kossel mini with Minitronics, Prusa i3 MK2

my fan has started to go -

[youtu.be]

if you are thinking of replacing your fan check this thread [forums.reprap.org]. the silence is wonderfull
John