Jump to content
Bad_Mechanic

Issues with combing

Recommended Posts

Posted · Issues with combing

My Ender 3 was making a very strange "thump" sound while printing. Unfortunately, the sound is quite loud and disturbs my wife. I finally figured out what it is. Right before Z moves up one layer, the table executes a very rapid and very short back back and forth movement, and it's that movement which is causing the sound. It turns out that movement is caused by combing. However, when I turn combing off, I get blobs on the surface at the Z axis transition points.

 

I'd appreciate any help in figuring out a solution to eliminate or minimize the thumps, while also preventing surface blobs. 

Share this post


Link to post
Share on other sites
Posted · Issues with combing

There are two gcode samples attached. They are from the same STL file, with the only different being the print temperature and combing being turned on/off.

 

200.gcode has combing turned off, it does not make the thumping sound when printing, but has surface blobs.

 

195.gcode has combing turned on, it does make the thumping sound, but does not have surface blobs.

200.gcode

195.gcode

Share this post


Link to post
Share on other sites
Posted · Issues with combing

Hello @Bad_Mechanic, thanks for the files. Actually, both of those gcodes are using combing. The only differences they have are in the print temperature. I think the project file could be more useful as that will show me the settings so could you please attach that. Thanks.

Share this post


Link to post
Share on other sites
Posted · Issues with combing

There's a very good chance I mixed up the files as I was doing this at midnight this morning. When I get home I'll redo my test files with combing being the only difference, run both of them to verify them, and then update this thread.

Share this post


Link to post
Share on other sites
Posted · Issues with combing

Thanks. Meanwhile, I think I know what's happening. You can reduce the size of that little wiggle by using the "no skin" combing option. It will still wiggle a little but not as much. I am looking into how it can be removed completely.

Share this post


Link to post
Share on other sites
Posted · Issues with combing

FYI, this little wiggle is not caused by a problem with the combing per se. What's happening is that the slicer is moving the nozzle away from the perimeter wall so as to avoid doing a retraction on the wall. This may have made sense in the past, I am not convinced it is beneficial. There is currently no way to disable it.

  • Like 1

Share this post


Link to post
Share on other sites
Posted · Issues with combing

Sorry for the slow reply. The new files are attached. They should be identically aside from combing. I printed both an verified that no combing left blobs and with combing made the thumping sound.

 

I also tried the no skin combing option, but it didn't seem to be any different from the combing option.

 

 

200_combing.gcode

200_no_combing.gcode

Share this post


Link to post
Share on other sites
Posted · Issues with combing
3 minutes ago, Bad_Mechanic said:

I also tried the no skin combing option, but it didn't seem to be any different from the combing option.

 

Using the no skin combing only reduces the size of the wiggle, it doesn't remove it altogether.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Our picks

    • Ultimaker Cura 4.0 | Stable available!
      Ultimaker Cura 4.0 is mainly focused on the improved user interface and cloud integration.
      As always, we want to collect your user feedback for this release. If there are any improvements you can think of, feel free to mention it here and help us to shape the next release.
      • 98 replies
×
×
  • Create New...

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!