Jump to content
Ultimaker Community of 3D Printing Experts

Under-extrusion - Is your Bowden tube 'really' clean?

Recommended Posts

Hi all,

I, like most people on here have had and the occasional 'unexplained' under-extrusion issue - one minute printing fine and then the next, thin layers, gaps and weak extrusion.

Interestingly for me, i was printing Ninjaflex over the weekend and i had an issue with under-extrusion. Nozzle was clean and extruder tension was fine. But then i noticed in the Bowden tube a 'hair' of previous filament stuck in the tube - almost invisible, but had been left behind from the previous 'change filament'. I had to disconnect the tube at both end and run a piece of filament through and then i noticed the 'hair' bundling up into a mini birds nest as i pushed it through and out of the tube.

A quick lube with some Olive oil and the Ninjaflex slid through the tube with ease.

I know this won't be a 'fix all' solution, but something to check if you don't already?

NOTE: don't be tempted to blow through the tube to clear it, it'll only leave behind moisture which will make filament stick like crazy - ask me how i know...


Edited by Guest

Share this post

Link to post
Share on other sites

This is what I do (with PLA):

- heat the nozzle up to 200°C

- open Robert's feeder

- push a bit of filament manually through the nozzle

- let the nozzle cool down to x (x=90°C on my UMO, 80°C on my UM2 with the original heater block, 70°C on my UM2 with the Olsson Block)

- pull the filament out (requires some force)

- use the 'insert filament' option in the advanced menu to insert new filament

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.
      • 0 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!