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

extrusion amount depends on temperature and layer thickness

Recommended Posts

In some print I noticed that if I increase the speed, wall thickness seems to go down.

That can have more than one cause. So I set out and do some tests.

I print a simple hollow cylinder which is single walled. I set wall thickness to 0.5mm.

I vary speed (mm/s) and layer height (mm), and measure wall thickness with a digital caliper.

To have a smooth wall, I turn on the "Joris" option, so that the z increases steadily during the print.


 speed, layer->wall thicknessAt  205 degrees          215 degrees    50, 0.1 -> 0.48     50, 0.1 -> 0.53         50, 0.2 -> 0.44     50, 0.2 -> 0.53         100, 0.2 -> 0.28    100, 0.2 -> 0.35     


So it is clear that the more the extruder has to spit out (mm3/sec), the thinner the wall becomes

If I increase the temperature, this effect becomes less.

I my view, temperature should not influence the amount of plastic that is extruded.

So what is wrong?

My current hypothesis is that my filament drive is slipping, due to the force needed to press the filament into the extruder head.

My UM is from september 2012, and came (I think) with the latest knurled bolt.

I have a self built "Bertho" drive. Since I have no real info on needed force, I just used a spring I could find at work.

The slipping is subtle, there is a clear trend in the figures.

Before I start a big investigation in this, a few questions:

* With what force should the filament be pressed into the knurled bolt?

* Is a perfect press force a gurantee for no slipping?

* Or is there always a relation between drive force and drive length? I think for perfect volumetric extrusion, there should be no such relation.

Share this post

Link to post
Share on other sites
I my view, temperature should not influence the amount of plastic that is extruded.

Unfortunately, it depends a great deal on the temperature, or more precise, at the heating capacity of the hot end. the lower the temp the higher the viscosity, which is counter-balanced by low printing speed.

if you print faster (more mm^3/sec), you need a higher temp (as your data confirmed).

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

    • Architect Design Contest | Vehicles.
      We're open for entries! - Design and submit your 3D designs of architectural entourage - vehicles - for a chance to win a large filament pack. Presenting an idea, an architectural design or something as big as an urban project isn't easy. A scaled model can really help to get your idea across.
        • Like
      • 24 replies
    • What The DfAM?
      I'm Steve Cox, an experienced engineer familiar with 3D printing. I wanted to share some DfAM guidelines with this community to help and make stronger parts.
      I'm also an Autodesk Certified Instructor for Fusion 360, so many of the images in ...
        • Thanks
        • Like
      • 23 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!