Jump to content
Ultimaker Community of 3D Printing Experts
Sign in to follow this  

Problem with um2 fans hitting wall - solved

Recommended Posts


I was very happy to receive my Ultimaker2 today, and after a test print i run in a few problems:

some are not very important,

1) they where only 2 tie-wraps and not 4 like mentioned in the manual, no big deal, but maybe this created more important problems during transport, specially with fedex, the box was delivered upside down with big marks on one side, do they throw it around playing soccer with it ?

2) there where only one file on the SD-card, (MiniCalTest), so i had to download the "UltimakerRobot_suppo", no big deal, but all this doesn't look to serious for Ultimaker, specially for that price and i don’t know what other files i am missing, please let me know.

Some are important,

1) the two side fans go on and off during printing when they are set to 100%, i found that if i set on printer under 100% like 98%, they don’t stop anymore, but then they keep on dropping speed, so i have to readjust to 98 every 10 seconds, whats wrong with those fans ? how can we fix that ?

2) the light from the leds are slightly flickering during prints, its subtle but quite annoying, and beside that i fear it might get worse and be the sign of a bigger problem.

I know ultimaker have been under quite a pressure lately with a big number of orders, so i understand its hard to have everything perfect, but on the client side its quite disappointing (((

Please help me to quickly solve these issues, specially with the fans, since it prevents good prints.



Share this post

Link to post
Share on other sites

Pull up the mesh that surrounds the wires above the print head and find the three red-black wire pairs that go to the fans. (one on the back, two on the sides). Check the connectors all seem good.

(BTW, are you viewing these in daylight? When viewed solely in the light of the LEDS, strobe effects can sometimes make the fans seem to do weird things - especially if the lights are at less than 100% brightness).

The lights can tend to flicker subtly due to some electrical interference/timing issues, but it's not too serious, and I think they might be able to work around it by refining the firmware at some point. There can also be mechanical flickering caused by the led strips or wires catching on the pulleys, in the top corners behind the front panel. Check those to make sure that the wires joining the top and side LED strips aren't bending away from the wall and catching on the pulleys or belts. If they are, a drop of superglue can help keep them pressed against the wall, out of the way.


Share this post

Link to post
Share on other sites

The light flickering is normal. It happens when the temperature of the bed approaches the goal temperature - within something like 15 degrees. The amount of energy going to the bed is considerable and when the power is turned on and off 10 times per second that is plenty slow enough for eyes to detect. You can turn the LEDs off if you want.

About the fans going on and off a lot - that's probably in the gcode - did you download a gcode file or slice your own? The original robot gcode file was not sliced with cura. It's a slicer that turns the fan on and off depending on all kinds of things like how long the layer will take to print, if there is bridging happening, or overhangs.


Share this post

Link to post
Share on other sites


Thanks for your answers,

The fans are working fine when they are set to 99% or less, but as soon as they are on 100% they go on and off every 5sec or so, wether i set them in cura or on the printer, i hope its not a latent probleme that will soon appear...

i also have another probleme with the x course endstop, its in place, it works, but the head goes all the way left to the wall, so tightly i cant slide a piece of paper between...

any clues ?

mars2014 037

mars2014 036

mars2014 035

mars2014 027

mars2014 028

mars2014 030

mars2014 031

mars2014 031

mars2014 032


Share this post

Link to post
Share on other sites

Regarding the fans hitting the wall, there are two things you can do: 1) bend the fan down a bit to close the gap between the part with the fan, and the main body of the print head or 2) bend the lever on the x-stop (located in the back right corner, on the underside of the top plate of the printer) a little to the right, to cause the endstop to engage sooner. The easiest way to do that latter one is with a pair of curved needlenose pliers.


Share this post

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
Sign in to follow this  

  • Our picks

    • Ultimaker Cura | a new interface
      We're not only trying to always make Ultimaker Cura better with the usual new features and improvements we build, but we're also trying to make it more pleasant to operate. The interface was the focus for the upcoming release, from which we would already like to present you the first glance. 
        • Like
      • 130 replies
    • "Back To The Future" using Generative Design & Investment Casting
      Designing for light-weight parts is becoming more important, and I’m a firm believer in the need to produce lighter weight, less over-engineered parts for the future. This is for sustainability reasons because we need to be using less raw materials and, in things like transportation, it impacts the energy usage of the product during it’s service life.
        • Like
      • 12 replies

Important Information

Welcome to the Ultimaker Community of 3D printing experts. Visit the following links to read more about our Terms of Use or our Privacy Policy. Thank you!