Jump to content
Ultimaker Community of 3D Printing Experts
hiltonmw

Pre-Printing Extrusion

Recommended Posts

Hi Guys,

This may be a wayyyy newbie question... when I print files on my Ultimaker 2+, it heats the buildplate and the nozzle appropriately, and then it "pre-extrudes" quite a bit of filament. Is there a way to dial back how much "pre build" filament is extruded? It seems excessive on my printer, compared to what my previous Makerbot used to do.

Share this post


Link to post
Share on other sites

Have a look in Cura under the tab called "Start/End-Gcode"

If you click the start.gcode file, you will see some lines of code that always gets added to the top of your gcode after slicing (it eg. homes the printer, zeros some values, stops the fans etc.)

There should be a line saying something like:

G1 F200 E3              ;extrude 3mm of feed stock

The number after the E is the amount of filament (in mm.,) extruded before the print starts, play around with that value.

Don't turn it off completely, the hotend needs to be primed so that process is not happening during the printing of the first layer... Otherwise you will get terrible bottom quality and adhesion problems.

I always print with 3-5 lines of skirt, which performs kind of the same function (It starts the print by printing lines at a certain distance around the perimeter of your model), but also will let you do a bit of "on the fly" bed leveling before the actual print starts...

Edited by Guest

Share this post


Link to post
Share on other sites

The start and end code tab isn't available if you're using an UM2/UM2+ machine unless you switch the "Gcode flavour" in the machine settings in cura. I wouldn't do that unless absolutely necessary.

The amount of priming is set in the firmware for the UM2 so you'll have to re-compile the firmware if you want to change it.

Share this post


Link to post
Share on other sites

The start and end code tab isn't available if you're using an UM2/UM2+ machine unless you switch the "Gcode flavour" in the machine settings in cura. I wouldn't do that unless absolutely necessary.

The amount of priming is set in the firmware for the UM2 so you'll have to re-compile the firmware if you want to change it.

 

Alrighty then, I did not know that... I have seen it in my firmware for the UMO as well when playing with that... So which one counts for the UMO? That set in Cura, or the one from firmware?

Share this post


Link to post
Share on other sites

Lol using Repetier Host I extrude 30mm of filament before starting the print to make sure everything is looking good, that is 30mm of perfect flow. If I get a nasty during the process, maybe a bit thin, I start the 30mm again. So not sure that 3mm is bad, apart from being too little :)

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

    • Print Core CC | Red for Ruby
      Q: For some users, abrasive materials may be a new subject matter. Can you explain what it is that makes a material abrasive when you are not sure which print core to use?
      A: Materials which are hard in a solid piece (like metals, ceramics and carbon fibers) will generally also wear down the nozzle. In general one should assume...
      • 1 reply
    • "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!