UM: Poor overlap between the shell and infill

[artifex 0]

I recently have started seeing a problem where my infill does not overlap with the shell, so layers never bond and the shells peel off easily. The gap seems to be bigger on the backside of an object and the head never makes it all the way to the shell. In the picture below the Infill Overlap % is 17% on the left and 20% on the right.

I believe this started happening after my recent round of calibration. I calibrated the X/Y/E steps and squared the axes.

Any suggestions on how I can fix this?

Thanks!

 

[illuminarti 18]

Is this on a UM Original or a UM2?

In either case, the most likely cause of this is backlash - which is usually caused by too little tension in the belts - particularly the short belts. So loosen the motors and press the motors down while retightening the screws.

You might also add belt tensioners to the long belts, but that is easier to do on a UM1.

 

[nick-foley 5]

Also, you're underextruding, which is probably not causing the problem but definitely making it look worse.

 

[jonnybischof 60]

For me, setting the infill overlap to 16% (15% is standard I believe) has always worked well. If I set this higher, then I get notable overextrusion on the overlaps.

First of all, you should set it back to 15 or 16%, then try to solve the issue by doing what the others said above. Leaving it at 20% will most probably lead to bad results in any case...

The fact that it occurs only on top and bottom, but not left or right sides, suggests that you have a backlash / belt tension problem, but only one one of the two axes. Still check and tighten all belts so that you can be sure this is dealt with.

Maybe check the pulley setscrews, they need to be really, really, really tight.

 

[artifex 0]

Thanks everybody for the suggestions!

I have an original Ultimaker. There are belt tensioners on the x-axis but not the y-axis (can't get them installed).

I did the following (all at once without an attempt to be scientific):

 

• Attempted to install belt tensioners
  
• Checked that all the set screws tight.
  
• Reset the E steps back to the default value
  
• Reset my Cura configuration
  
• Played with infill overlap and ended up at 16%
  

The end result is I have a much better result. I am going to try and print up a better belt tensioner now and see if that helps.

Again, thanks for all of the suggestions.

 

[jonnybischof 60]

Looks much better already! *thumbs up*

Always glad to help