Adding second print fan

I want to add a second print fan to my mini. I’m having issues with PLA curling and I’ve had some better results with additional cooling, but it’s largely by having a desk fan blowing across the printer while printing. This is suboptimal because it also cools down the hot end and bed.

I printed a fan shroud and have a fan for it, but what’s left is wiring and this is where I’d like to get some suggestions.

Soldering isn’t a strong point for me, but it seems like it would be easy enough to snip, splice and solder the new fan in parallel with the existing one. Then use some shrink tubing to clean up the join.

But I understand I could also run it all the way back to the board and basically just crimp a new connector. I’d still have to do some soldering to connect the fans to the new leads, but it feels “cleaner” – but also a lot more work given that I’d have to disassemble and clean up the wiring harness to/from the hot end.

Has anyone added a second fan and have any tips on the best approach - along with at what point this sort of thing would run afoul of the basic warranty?


I’d just run both fans off the same leads. controlling multiple fans without multiple extruders in play gets complicated. And as far as warranty voiding goes, you probably void the warranty when you cut a wire or admit to having ran a different wire in public.

Having read and reread his post, I don’t think “bmemike” has yet taken any action. He has suggested either splicing the new fan into the existing fan’s circuitry or running an entirely new circuit as possible courses of action and wants some experienced input before proceeding, thus no voided warranty - yet.

I am of the opinion that running a new line that plugs into an existing power rail on the Rambone board has the least chance of voiding the warranty as it does not involve cutting wires and possibly overloading a circuit that was intended to have only one fan on it. “bmemike” has suggested that this may be a cleaner solution and I agree with that assessment. However, his admitted lack of soldering skills may prove to be problematic whatever option he chooses. (Keep at it, the more you do it, the better you get!)

I am interested to learn about single vs dual fan setups and the advantages each provides and I’m curious why, other than cost reduction, Aleph Objects chose to go with a single fan design for the Mini while a competitor, the Ultimaker 2 has a dual fan design.

The ultimaker 2’s competitor is a Taz. The mini is a lower cost, fewer options, smaller printer. Dual fans didn’t start to become a recognized option as a desiarable trait (for cooling both sides of a PLA part fillament at the same time) until after the initial run of mini’s were completed. The Taz 6 is the first production Lulzbot printer that ships with Dual fillament coolers. It doesn’t look like the codename Gladiola next Mini design will have duals either at this point, but it is a very small area to fit a second fan into anyways.

Correct - I’m trying to assess options as well as source opinions from the community before taking any action. I’m also secretly hoping someone has added already additional cooling to their Mini and can offer any first hand experiences with whatever route they took as well.

After additional poking around, I’m also not adverse to a fan shroud to wrap some cooling around the nozzle and have been brainstorming ideas on that as well. It’s certainly the least invasive mod-wise - but I’m not sure if it will be sufficient cooling-wise.

There’s actually plenty of space to drop another fan hood and attach it using the existing mounting bolt on the left hand side. I’ve seen people take this route with TAZ 5’s, for instance.

I found this recently and it piqued my interest:

Funny you should say that because the major selling points of this printer were that it included a heated bed and automatic bed leveling - features that you normally don’t find in printers unless you double the price. I had my heart set on an Ultimaker 2 until I found out about the Mini for nearly half the price.

the fewer options piece was specifically in reference to the lack of an LCD and SD card reader in that context.

I’ve seen that as well - but unlike some TAZ mods, I’m pretty sure this one won’t just work without changes to the STL.

I don’t have a TAZ 5, but from what I can see the fan mounts to the extruder bracket perpendicular to the ground. The Mini’s mount point is at something like a 45* angle.

That’s part of the reason why something like was initially attractive.

If you end up playing around with it, please share!

I’m curious if anyone has figured out a good solution for cooling prints. I printed out the piece previously linked that redirects some of the air to the other side but ended up not getting it mounted. One of the limit switches actually mounts to the fan shroud and the holes aren’t in the same place on the mini.

What I’ve been doing is just getting a fan and pointing it at the print surface when I need extra cooling. I bought an 80mm computer fan and run it from a 9 volt battery. Of course that just stays on the whole time and cools everything including the print bed and hot end.

edit: spelling

Hi Everyone,

Has anyone completed this mod yet? If so, I’m curious where you connected the wires from the new fan to those of the old fan. Thanks

I’m personally a big fan of my design :slight_smile:

Been using it for a while now, works great. Have no problem printing 70-80 degree overhangs in PLA :slight_smile:

This looks like it should do the trick. I was thinking about upgrading my heat sink blower to a 40mm fan. I’m guessing that might be hard to do with this design?

Yes I designed this for the original printhead design with the blower.

Dang, I figured. Thanks for the info! :slight_smile: I’m going to try and design a solution to fit both upgrades. If it doesn’t work, I’ll probably go for your upgrade. I’ll post my results!