Jump to content
Sunrider

Zones of my print not printing

Recommended Posts

Posted · Zones of my print not printing

So i just got my printer 2 weeks ago and it did a pretty good job on the first prints i've done, wich they were quite small. I started printing larger things a few days ago, wich it was what i bought the print for. And i seem to get this kind of under extrusion problem in some parts of the print, only at certain hights, because as you can see in the image it kinds of corrects itself in the next hightsIMG-20190831-WA0012.thumb.jpeg.466a01e482a48194c4fc507885bbc05c.jpegIMG-20190831-WA0010.thumb.jpeg.d9c5aad5b541cf8ce09aaee2c70ae8ae.jpeg

any guesses on how to fix this problem? 

ive read that it might be a problem of the retraction being set too high, but i dont think it might be that

Share this post


Link to post
Share on other sites
Posted · Zones of my print not printing

That seems extremely specific - that underextrusion.  It goes from good extrusion to massive (maybe only 20% extrusion) underextrusion (80% less than normal).  Well first thing to try is to slow it down.  You can experiment live printing - most printers have a TUNE menu while it's printing where you can reduce the print speed to say 50%.

 

By default I think cura prints infill at 2X speed so it could be this is where it switches from infill to outer wall and it takes a few seconds to get back up to pressure.  It could be your infill is even worse underextruded.

 

I'd look at the part in preview mode in cura carefully to see what's going on here.  use the "play" feature and the horizontal scroll to see exactly the path the head makes.

Share this post


Link to post
Share on other sites
Posted · Zones of my print not printing
29 minutes ago, gr5 said:

That seems extremely specific - that underextrusion.  It goes from good extrusion to massive (maybe only 20% extrusion) underextrusion (80% less than normal).  Well first thing to try is to slow it down.  You can experiment live printing - most printers have a TUNE menu while it's printing where you can reduce the print speed to say 50%.

 

By default I think cura prints infill at 2X speed so it could be this is where it switches from infill to outer wall and it takes a few seconds to get back up to pressure.  It could be your infill is even worse underextruded.

 

I'd look at the part in preview mode in cura carefully to see what's going on here.  use the "play" feature and the horizontal scroll to see exactly the path the head makes.

Now that you say that, i think the problem might be related with another problem i have, where as soon as the hot end gets hot filament starts to extrude by itself, i know this is a normal thing to happen, but it extrudes quite a lot of filament, and it does this everytime, so filament comes out the nozzle even when its not supposed to, when the head is travelling for example.

Share this post


Link to post
Share on other sites
Posted · Zones of my print not printing
9 minutes ago, Sunrider said:

so filament comes out the nozzle even when its not supposed to, when the head is travelling for example.

That's relatively normal.

 

There is something called "retraction" which is turned on by default in cura.  It retracts the filament a little bit when the print head goes over a gap.  If you retract too much you get air in the nozzle and you get over and underextrusion.  If you retract too little you get little strings across gaps where you don't want them.

 

Basically the print will be most perfect if you never speed up or slow down the printing speed but sometimes you have to stop when you go across a gap.  Cura by default does lots of speed changes which can cause under and overextrusion each time there is a speed change.  So I always make all the printing speeds the same (but the non-extruding "travel moves" as fast as possible).

 

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

×
×
  • 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!