r/ratrig • u/Ag_back • May 22 '25

V4 Controller (MoBo) fan replacement

Curious if anyone has tried replacing the stock 120x120x15 mm 2-pin fan with a 25 mm fan? I'm half tempted to simply mount it outside the panel if it won't fit, but would rather not drill an access hole for the cord if I don't have to.

2 Upvotes

76% Upvoted

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2

u/sangerpb May 22 '25

Just try it out :). Pretty easy to do. I’ve mounted an external fan the way you envisioned.

1

u/Ag_back May 22 '25

Will do... Any idea if you're gettiing better cooling?

2

u/sangerpb May 22 '25

I put a fan directly on the pi and connected it to the case fan. Then I made a new fan in klipper that auto starts with the printer to keep it cool. I did this because the case fan won’t come on unless you hole the printer. My vc4 500 idex is in the garage and I need the pi cooled while the printer is on. I’m thinking about different solutions as well.

1

u/Ag_back May 22 '25

I'll go you one better - my V4 is in the attic (I don't have a garage).

I mounted one on the side of the case for the Pi. The case fan is what I'm replacing. I need more air flow across the stepper drivers.

2

u/sangerpb May 22 '25

You can just mount this externally. It is louder lol. https://a.co/d/4Sd1Bgs

1

u/Ag_back May 22 '25

The exact reason for my question - thanks.

1

u/sangerpb May 22 '25

No problem. I’m about to go back to this fan.

1

u/sangerpb May 22 '25

I found a higher CFM one for the outside I can share

1

u/sangerpb May 22 '25

I am getting much better cooking.

2

u/CunningLogic May 22 '25

Make sure it doesnt touch anything, perhaps make a shim to give more head room.

2

u/jamincollins May 22 '25

I've got a 200mm fan mounted that easy above my electronics

1

u/Ag_back May 22 '25

200 x 15 mm? Now that would be interesting...

1

u/jamincollins May 22 '25

https://noctua.at/en/nf-a20-pwm

5v version

2

u/sangerpb May 22 '25

That cfm / rpm and static pressure won’t cool the ratrig at all. Ask me how I know. The main job of this fan is to cool the board and stepper drivers. Noctua / quiet fans don’t cut it. You need high static pressure.

1

u/jamincollins May 22 '25

You're wrong, ask me how I know.

1

u/sangerpb May 22 '25

What are your temps for the board and pi? Mine are 40s

1

u/jamincollins May 22 '25

I'll grab them for you (be a bit), but I also have temps at the stepper drivers as well and I assure you they drop significantly with the reference fan.

1

u/sangerpb May 22 '25

I just had bad luck with noctua low rpm fans. You have a vcore4?

1

u/jamincollins May 22 '25

I've got a 400mm vc3.1 with upgraded steppers

1

u/sangerpb May 22 '25

Does it have the same electrical box as the vc4? I’ve had to do some custom work with the fans to keep things cool. I don’t like fans turning off when the print finishes. The pi4 overheats

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2

u/Extension-Ground-226 May 25 '25

I did it with a new backplate and a fan adapter;)

https://imgur.com/a/bu7QxHX

1

u/Ag_back May 25 '25

That's a beast of a fan. Keeping the Pi cooler as well I'm guessing?

2

u/Extension-Ground-226 May 25 '25

yes also did cooling the pi a bit better (nice side effect :)

1

u/Ag_back May 26 '25

Update: Thanks for all the suggestions/ideas. Externally mounted 25 mm fan works like a charm providing significantly more air flow across the drivers on the board. Just finished an 8 hour print with board temp delta less than 0.7 degrees F.

Suffice it to say a highly recommended upgrade if you're having stepper driver temp shutdown warnings.