Jump to content

UM2-RearFan-Automatic (The UM2 silence, and I in my little living room.)

Recommended Posts

Posted · UM2-RearFan-Automatic (The UM2 silence, and I in my little living room.)

You can solve with little knowledge in electronics, this problem yourself. If they feel the constant fan noise very disturbing, then there is at least one effective solution:

There are bimetallic temperature switches for various applications and in various designs, which are available at a predetermined temperature ranges.

For the rear UM2-fan, is ideal a TLRS-9700 @ 40 degrees "NO" (-NORMAL OPEN (...This compact thermal switch closes an electrical circuit when it reaches the specified temperature.)).

TLRS 9700 UM2 RearFan #1

The price for such a part is far below 1 euro / dollar. The time required for the successful implementation is very low. Ask a friend if you do not trust yourself to do this work.

The switch can be integrated without additional electronics in one of the two fan-lines. It needs a little soldering knowledge and in addition some heat shrink tubing for proper insulation.

Warning, avoid short circuits:

The metal housing of the thermal switch is electrically connected to one of its leads, so an integration in the ground line of the fan must be done. Otherwise, the housing of the thermal switch can be completely packed into heat shrink tubing, in order to obtain a good electrical insulation.

The temperature switch fits easily into the UM2-print-head housing, and should be mounted horizontally on the top aluminum plate. There are on the aluminum plate an unused hole with M3 thread, this could be used for the mounting of the switch.

How it works:

The required 40 degrees to the thermal switch can be achieved in the upper print-head range with much delay, as there is to be considered a passive cooling. As soon as the nozzle temperature continuously exceeds 70 degrees, the passive cooling is no longer sufficient and the rear fan starts its work. In the recommended mounting of the thermal switch, the temperature difference is as about 30 degrees. Measured from the start of heating from 25 to 210 degrees, a fan-on-delay of less than 2.5 minutes is the result. If the nozzle temperature below 70 degrees again, then the rear fan is inactive.

Negative side effects?

I would say NO ...

I'm no expert, so I can therefore only report on the more than 100 hours of usage experience since this small modification: The PTFE ColdEnd does not seem to suffer from the cooling delay, the Ultimaker 2 continues to run smoothly.


A mounting example:

TLRS 9700 UM2 RearFan #3TLRS 9700 UM2 RearFan #2

Even if later there will be an official upgrade for a second Hotend, then there is sufficient space within the housing for this temperature Switch.



  • Like 3
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Our picks

    • S-Line Firmware 8.3.0 was released Nov. 20th on the "Latest" firmware branch.
      (Sorry, was out of office when this released)

      This update is for...
      All UltiMaker S series  
      New features
      Temperature status. During print preparation, the temperatures of the print cores and build plate will be shown on the display. This gives a better indication of the progress and remaining wait time. Save log files in paused state. It is now possible to save the printer's log files to USB if the currently active print job is paused. Previously, the Dump logs to USB option was only enabled if the printer was in idle state. Confirm print removal via Digital Factory. If the printer is connected to the Digital Factory, it is now possible to confirm the removal of a previous print job via the Digital Factory interface. This is useful in situations where the build plate is clear, but the operator forgot to select Confirm removal on the printer’s display. Visit this page for more information about this feature.
        • Like
      • 0 replies
    • Ultimaker Cura 5.6 stable released
      Cura now supports Method series printers!
      A year after the merger of Ultimaker and MakerBotQQ, we have unlocked the ability for users of our Method series printers to slice files using UltiMaker Cura. As of this release, users can find profiles for our Method and Method XL printers, as well as material profiles for ABS-R, ABS-CF, and RapidRinse. Meaning it’s now possible to use either Cura or the existing cloud-slicing software CloudPrint when printing with these printers or materials
      • 48 replies
  • Create New...