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

Feeder Grinding Material Prevention

Recommended Posts

UM Original or UM2? The UM2 shouldn't grind most filaments as it has a lower current applied to the feeder so that it will slip backwards instead of grind.

And did you have mega retraction? If um2, count the M11 commands in the gcode and look at the final extrusion position in mm and see how many retractions you had per mm. I've done 8 and was fine (same filament went back and forth through feeder 8 times. On average meaning sometimes more than that).

On UM1 in general you can raise temp or lower speed to get less forces, less pressure in the head, which reduces grinding.

 

Share this post


Link to post
Share on other sites

On the UM2 it can help to check the spring tension. In general if you received your machine prior to March 1st (2014) the white little indicator should be in the top position, if you've received your machine after that it should be in the middle position. But, that's just the default setting and depending on your filament you might benefit from tweaking it.

Unfortunately on the earlier machines you can only make it tighter though. Unless you snip off a ring or two of the spring perhaps? Just a random thought.

Also make sure that the little knurled sleeve that drives the filament is clean.

And of course check that there isn't unnecessary friction on the filament and that you're not printing too fast/cold.

 

Share this post


Link to post
Share on other sites

With the original (excessively strong) extruder spring on the Ultimaker², it was very rare to get extruder grinding, even during retractions.

It is more likely to happen with the newer extruder spring that has been shipping since March. On those machines, the key seems to be to increase the extruder tension a little bit if you get grinding... with enough tension, the motor should be able to grab the filament sufficiently tightly that the motor will step back, rather than grind the filament.

 

Share this post


Link to post
Share on other sites

Interesting; I get grinding but it happens for very specific reasons: if I print really cold (5C away from no extrusion cold), the buildplate is too close to the nozzle, or I'm trying out new firmware. Do any of these apply to your situation? The only other time I got grinding was actually in the middle of a print because my filament was weaved under itself and knotted up; the extruder pulled like hell on the filament though, it was full of kinks where it interfaced with my filament guides.

 

Share this post


Link to post
Share on other sites

I experienced a bit of this when I changed the material for the 2nd time. I've noticed a significant reduction in it by using a different spooler mechanism so the tension isn't so hard on the right side of the feeder intake. This one worked well for me, and it sits under the the table that the printer is on feeding directly upward into the feeder. http://www.thingiverse.com/thing:290064

 

Share this post


Link to post
Share on other sites

I've gotten grinding 3 times in the last 3 days, only once on a print with a lot of retractions (Coral Cuffs on Thingiverse). I've touched the stepper feeder shaft before and it was pretty warm, possibly softening the PLA in there now, making it easier to grind. I'm going to give IRobertI's feeder a try and see how that works (if I can get it to print).

 

Share this post


Link to post
Share on other sites

Hi,

I had a lot of trouble with grinding/slipping filament with a new elastic PLA from Form Futura; the Flexifil.

After three times removing the filament in the bowden tube I gave up.

I do not know if this has something to do with the tension only; the flexifil is quite flexible and probably has this trouble because it is more easily compressed.

would it be recommendable to screw up the tension even more?

Regards,

 

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

    • Introducing Ultimaker Cura 3.6 | Beta
      Ultimaker Cura 3.6 | Beta is available. It comes with new features, bug fixes, and UX improvements. We would really like to have your feedback on it to make our stable release as good as it can be. As always, you can download the beta for free from our website, for Windows, MacOS, and Linux.
        • Like
      • 75 replies
    • 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...
        • Like
      • 26 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!