Jump to content
Ultimaker Community of 3D Printing Experts

What Defines the Length of the Bowden Tube

Recommended Posts


Hope someone can shine a light at what defines the Length of the Bowden tube..

Reason My Um 2 has a Bondtech and the bowden has a nasty habit of going nearly flat not upright,, this makes the entry into the top of the head and the exit from extruder, under pressure, and I would think cause more friction pushing the material through...

So I thought as long as the tube was NOT being stretched by the head moving across the med to all 4 corners that would be fine...

Any thoughts before I cut...

Share this post

Link to post
Share on other sites

Pull the tube out of the hotend, take it to the front right corner (the furthest corner), see how long you can stick it under the height of linear rod without too much bending.

The next thing you need to concern is the fast forward filament run while loading filament. You need to make sure the extruder doesn't outrun your Bowden tube, otherwise the filament is going to shove into the nozzle and be grinded by the extruder.

In the 2.1 Marlin firmware, default Bowden length is set to 705mm (set as FILAMANT_BOWDEN_LENGTH in Configuration.h tab).

And the fast forward length is FILAMANT_BOWDEN_LENGTH-50mm (set as FILAMENT_FORWARD_LENGTH in UltiLCD2_menu_material.h)

If you cut the Bowden tube, better subtract 705 with the length you cut off.

With your problem of Bowden tube not being up right, you could also try a Bowden tube hook to restrain the position. I made one before: http://www.thingiverse.com/thing:2154124

Edited by Guest

Share this post

Link to post
Share on other sites


thanks for the reply you made some points that I didn't think of ?? which is exactly why I asked the question?? thanks..

I will look at the Boden again.. The Ums 2 is not what it started life out as std.. and I guess I replaced the tube 2 or 3 times.. so I doubt it is std length I will look at the fast forward and check..

I also have another printer Not Um (sorry) which is heavily modded and I suspect that machines bowdens are well out, I will check the H files for the length before I cut 25mm off...


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

  • Our picks

    • How to 3D print with reinforced engineering materials
      Ultimaker is hosting a webinar where we explain how you can achieve and maintain a high print success rate using these new reinforced engineering materials. Learn from Ultimaker's Product Manager of Materials and top chemical engineer Bart van As how you can take your 3D printing to that next level.
      • 2 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!