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

Retraction setting: Is that linear speed of filament or the equivalent hotend speed?

Recommended Posts

I'm trying to fine-tune my steps/mm and retraction settings. I'm using Repetier to do the calibration because it gives much better manual control. I'm just trying to get the settings correct. I am confused about the units that Cura lists for retraction. It says mm/s. Is that mm/s of filament? Below is my interpretation of units. Can someone sanity check this?

Cura print speed (mm/s): linear speed of the hotend

Cura retraction speed (mm/s): linear speed of 3mm filament through the drive gear

Repetier speed (mm/min): linear speed of 3mm filament through the drive gear.


Share this post

Link to post
Share on other sites

Yes, retraction distance is the distance the filament is moved by the extruder gear in mm. However, this will not be exactly the case on the hot end. Filament will not necessarily move (for example) 4mm on the hot end side when the gears move it 4mm because of things like play in the bowden clamps and slight room in the bowden tube etc.


Share this post

Link to post
Share on other sites

It is the linear speed of the filament. However, in the firmware that ships with Cura for the Ultimaker-Original there is a bug that makes retraction slower then entered. Which is why 45mm/s is the default for the Ultimaker. After the fix a value of 20-25mm/s is more accurate.

Repetier lists mm/minute because that's what the firmware is actually reading. Cura uses mm/sec everywhere as those values are smaller and easier to comprehend in my book. mm/minute is a left-over from CNC milling which is much slower in movement then printing.


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

    • 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!