3D Printing Forum

I'm trying to understand why the UMO has fans to cool down the electronics.
What is the noisy fan for?
Is it for the LM7812 or is it actually for the 4988 stepper drivers overheating?
Or am I missing something else?

As if it's for the LM7812 as I now have replaced it with a DC-DC converter I could theoretically remove the electronic fan?

I wouold also love to get rid of it but I think the critical point are the stepper drivers... If you have the possibility, you could try to ckeck the temps during a longer print.

Well I was thinking about the stepper drivers too, but then if you check other boards like Ramps 1.4 or Megatronics 1.3 they do support the SAME stepper drivers but with no fan whatsoever.
So is it really the stepper drivers at this point?

The critical point is the socket mounted stepper drivers that do not got enough copper surface to take all the heat away.

They are very likely to overheat without the cooling fan, wich causes them to temporarily shut down and you get really bad layer shifting etc.

Most other boards with socketed drivers should not run without a fan either, especially not if sitting in a tight compartment under the printer, or you will get the same problems.

Thanks...at what temperature should we consider the heat to be too much?
I'm still curious about this and would really love to remove the freaking noisy fan

My fan is pretty noisy too, since day one!

It is definitely for the motor drivers...
I've seen people running without fan, but they let the air circulating (with holes in the bottom panel of the UMO).

I looked at my UMO+ which has an Ultiboard 2 and the PCB is brown around some drivers, so that board should also benefit from heat-sinks / cooling.

Also if you are running at 24v it will make even more noise

But you don't need that big blower, a smaller / quieter fan should do.

you will notice it immediately when the cooling underneath stops.. When for instance one of the wires is loose you will loose steps and get shifted layers immediately on the first/second layer, that fast....

Whatever, for the sake of motor drivers I replaced this: https://www.youmagine.com/designs/ultim ... ronics-fan
with this: https://www.youmagine.com/designs/mount ... iginal-umo

It is slightly quieter now, but those small heatsink are in the way.
I may be removing them at some point.

Amedee wrote: Also if you are running at 24v it will make even more noise

BTW, to put that in context, some board history here:

On the 1.5.3/1.5.4 boards the LM7812 is only used to deliver 12V to the electronics fan.
On 1.5.6 it is used to power both the electronics and the Arduino
And eventually on 1.5.7, it just powers the Arduino, the electronics fan is directly powered by Vin (so 19V by default).

So up to 1.5.6, the electronics fan is a 12V, and it has been replaced by a 24V one in the 1.5.7 build (if I believe the BOM for that one).

There were probably different fans in the 1.5.3-1.5.6 series, as mine is not that noisy...

last week I replaced my 1.5.4 board for a 1.5.7 board and the fan sounds different, more powerful... With the old board the fan would make a lot of noise first and then stabilize with less noise, I had to feel underneath to check if the fan was running. Now I can hear a stable hum from the fan.

Yes, you need to check the fan, it might not survive long with 19 volts

I just received a 1.5.7 as well to replace my old 1.5.3 so I checked all the board diagrams for differences, that's how I came on this fan thing...

thank, was not really aware of this. Is there a risk to let it stay there, will the fan die or something on the (new) board?

No risk for the board.
Worst case is that the fan could die as it gets 19v instead of 12v, but if it is running now it will probably continue to survive.
The head cooling fan on the UMO is also a 12V powered by 19V and they typically last very long

I'd love to find a way to get rid of the noise (and the fan) once and for all.
Any recommendations?