Ultimaker Original dual fan upgrade

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As shown on the Ultimaker 2+, two fans can have a huge benefit to the surface quality of your 3D print instead of having just one fan. For that reason, the first recommended upgrade to your Ultimaker Original is a dual fan set up. It may not sound difficult, but depending on how you choose to approach this there may be some challenges.

Dual Fan Ultimaker Original
Dual Fan Ultimaker Original

Before we begin, we'd like to thank Neotko, who’s been such a great contributor to this tutorial!

List of requirements

Dual Ultimaker Original Fan Parts
Upgrade parts
  • More fans!
  • 3D printed dual fancap – make sure to 3D print it before you start disassembling!
  • Soldering station
  • Heat-shrink tubing
  • Kapton tape, ceramic paper, or – if you want to be fancy – get Nomex paper
  • Recommended filament: CarbonFil from Formfutura. Warning: Carbon filament is considered abrasive and may wear down your nozzle
  • x8 M3 25mm screws
  • x4 M3 10mm screws for Ultimaker Original+, or...
  • x4 M3 steel nuts for Ultimaker Original
  • A drill with a 3mm bit to clean some holes in the printed fancap


So you’re interested in upgrading your Ultimaker Original to a dual fan set-up? Great! The first thing we need is to get two fans! But which ones? There are so many fans out there, different prizes, different sizes, different capacities.

A recommended and safe bet would be to use the same fans Ultimaker is already using on their Ultimaker Original (size: 50x50) or Ultimaker 2+ (size: 30x30) – you can easily pick up a pair from your local Ultimaker reseller. Of course, you can go at it alone, but finding a good alternative set of fans isn’t that easy. It might require a few attempts and there’s even a risk in damaging your electronics. Not all crucial settings are always listed and it could lead to breaking an SMD transistor. But if you’re the daredevil type and would like to source them yourself, try getting in touch with one of our experts for some help. If you have found a pair that works, please share your findings on our forum.

Things to watch out for

Transistors – the risks

A little background information about the transistor. You should probably not use more than 300mA combined. The transistor on the electronics can resist 500mA tops, but the pitfall isn't the power required to continue turning… the key is that fans need a certain amount of power to kickstart and get into motion. But be careful, that value can be higher than the value required to run and that can be a problem. This is a specification which isn't always listed. That’s why it may take a few attempts to find the right set of fans.


Dioder Transistor
Transistor & Dioder location

For 3D printing you also want a fan that’s capable of running at less than full power – this is so it has the option to gradually build up cooling. It’s a feature called PWM. Once you have a pair of fans it would be smart to test a few things before you start installing, the most important place to start would be to test if it is PWM-able and to what power. Connect it to your electronics board and go to Temperatures with the Ulticontroller. Set the fan to 128. If it 'spins' try 200. If it moves faster that’s perfect. If it doesn't, your fan might not be PWM-able and can only run at one speed. This probably won’t be a good fan for 3D printing.

If it did move faster, then you’re on the right track! Turn the fan completely off by turning it down to 0. Now set the fan speed to 100 and go down 10 after at least 3 seconds and keep watching the fans. If, for example, they stop spinning at 70, move it back up to 80. If at 80 they start to move very slowly then that's your 'start point’ in the firmware.

Try to avoid using fan speeds below the lowest speed you just tested as 'lowest'. That’s an easy way to break things on your Ultimaker board. Why? Because if the fans don't move and they keep getting power from the Ultimaker board, the energy 'builds up'. The Ultimaker electronics-board does have a dioder to block energy feedback, but it's better to be safe than sorry.


Feel free to get a coffee and read through the installation before you start.


Before you start disassembling your Ultimaker Original print head it would be a good idea to give it one last spin, because we need a 3D printed dual fan cap. We recommend you print one using CarbonFil from Formfutura, due to its characteristics when subjected to heat. CarbonFil does three things I like: when exposed to heat it becomes quite hard (not so hard that it breaks, but much less flexible), becomes glossy and compresses into itself – but without moving up or down.

Carbon Heat Exposed Front View
Inside and front views of fancap

Step 0. 'Before' print

Purely optional, but if you create a quick test print now to compare with a print after you've upgraded, you can really see how much of a difference the dual fan upgrade makes. This can be anything simple, like Ultibot!

Step 1. Download the files

You can get the STL files here on YouMagine:

Dual fan shroud STL
Fancap model parts

Step 2. Print the dual fancap

Print the dual fan cap and all other related parts using CarbonFil, with supports set to 'everywhere'. It may look like it’s not necessary in Cura, but it is recommended due to the filament characteristics. While enabling support, visit your expert settings and change the following:

  • Overhang angle for support to 70º
  • Infill overlap to 45%

Then use the following regular settings:

  • Temperature to 245º C (Depending on your thermo-coupler you may want to add or deduct 5º C)
  • Shell thickness to 1.2mm
  • During the print leave your fans off
  • Heated bed temperature to 75º C

Adding blue tape is also an option, in which case you don't need to use your heated bed. So it can be set to 0ºC.

Cura settings
Cura settings
Support comparison
Support comparison

Step 3. Two fans, one connection

Parallel soldering

Basically, if you want to connect two fans to the board, the best way to do this is to solder them in parallel. Ok, so what is ‘in parallel’? The best explanation is the one Neotko found when he was looking for this on the Ultimaker forums.

So basically you need to get two fans and connect them in parallel so both work at 24V, the shared power source. Red with red and black with black.

3.1 First, cut both the cables of your fans.

Soldering fans step 1
Cut cables

3.2 Grab the two red and blue / black cables and tie them together through a twisted motion.

Soldering fans step 2
Twisted cables

Add some soldering.

3.3 Add heat-shrink tubing to each fan.

Soldering fans step 3
Heat-shrink tubing added

3.4 Get one of the original cables that you cut in half, and solder the red end to the combined red+red to make it into one cable again. Do the same for blue / black.

Soldering fans step 4
Resoldered cables

3.5 Slide the heatshrink over your soldered connection and gently heat it with a lighter until the heat shrinks and secures your connection. Heat it in circular motions without staying too long in one place to prevent your cables from melting.

Soldering fans step 5
Finished fans

Step 4. Before assembly

Before assembling anything, get your tap drill bit and follow these instructions.

Tap the holes marked with blue circles

Next we'll be drilling the following holes.

drill the holes marked with blue circles

Step 5. Protect the fancap

Applying Kapton: Good
The good way

Next you need to protect the area that will get the most heat impact – this will be the part that surrounds the heater block. There are many ways to do this, but since we are using CarbonFil you will only need some Kapton tape. If you use any other 85º C+ heat resistant material I would check how it works under extreme heat. Some materials tend to curve on themselves, others move down and others change to a flexible state.

Like stated earlier, when exposed to heat this carbon filament becomes hard (not harder to break, but much less flexible), goes glossy and compresses into itself, but it doesn’t go up or down. So if you just use some kapton tape, it will hold the heat for quite a long time.

This is the recommended way to apply the Kapton tape.

Applying Kapton: Not so good
The not-so-good way

After using the kapton tape, remember to cut the hole in the center. But don’t over do it or the heater block will touch the kapton tape, and even though it will still work, it will transfer some heat away and your temperature will fluctuate.

As you can see in this picture, the heater block’s heat makes the carbon compress, but when you see its front view, it’s still ‘flat’.

CarbonFil after Heat Exposure
Inside and front views of fancap

Step 6. Assemble

Ok, now you are ready to assemble it! Check this animated instruction to see what goes where, and how it all looks after assembly:

One more important side-note; The symmetric-fancap-top-right.stl has 3 small dots on its side. This indicates where the hot-end ‘should’ be. There’s a 0.5mm difference on this side to prevent compression of the coupler. This area must fit just right without being too tight otherwise you’ll be supplying to much pressure on the coupler and that will shorten its lifespan.

Step 7. Almost done

We are almost there! You have just doubled your fan capacity, which means you probably want to tune them down a little bit – depending on what type of fans you bought. We want the fans to cool the extruded filament and not interfere with the deposition.

  • Open Cura, go to Advanced settings and open Expert settings.
  • On the left row you’ll see a section called ‘Cool’.
  • As a starting point you can start with Fan speed min 20% and Fan speed max 40%.

Now you are good to go. If you've made a 'before' print before the upgrade, create an 'after' print now and post a picture of them to the forum along with your best fan settings! We'd love to see how you've upgraded your Ultimaker Original. And of course, you can ask any questions you have regarding the upgrade there too!