PLA Gritty prints  

RE: PLA Gritty prints

Posted by: @stadslab-rotterdam

Hello all,

At our fablab we have 2 Prusa i3 Mk3 printers, which printed perfectly the last year. However, now one of our printers starts printing very ugly gritty prints.

Calibration lines are fine, but when it prints larger parts the prints get a very uneven finish.

Any thoughts?

 

Kind regards,

Evin

Stadslab Rotterdam, the Netherlands

Ik vermoed dat je hotend aan wat onderhoud toe is, de situatie die je schetst lijkt op under extrusion, het zou zomaar kunnen zijn dat je hotend verstopt of deels verstopt is.

RE: PLA Gritty prints

Wet filament can also cause printing problems.  Make sure you are using dry filament, either by opening a new spool, or by drying the filament before printing.  Or exchange filament between the "good" printer and the "bad" printer to see if the issue follows the filament.

Also, it is possible your nozzle has old higher temp filament stuck in it; you can try baking and flushing any older filament by increasing the nozzle temp to 280c and manually extruding 50 to 100 mm of new filament.  Then reduce temp back to normal.  There is also cleaning filament that helps with this maintenance chore (cleans better than using PLA).

And - as always - a photo that shows this grittiness will get a better diagnosis.

RE: PLA Gritty prints

This can be due to many issues - try a different filament, and then check to see if there is a partial clog (do a "cold" pull).

Then check your extruder - if the nozzle and heatsink are not tight and the pfte tube good, you'll see quality issues.

Finally check your PINDA probe is not sagging - I had many issues with prints and discovered that a lot of hot printing had caused my PINDA holder to sag - a particular issue with newer revisions of the extruder (think the latest version fixes it - I've been using for a few months with no new issues).  Lastly, it could just be a worn brass or copper nozzle.

RE: PLA Gritty prints

Thanks for your replies.

We had the issue for some time, so ordered new parts for the heat-end. We also changed the nozzle for a new one. However, with a new heat-end and nozzle the issues continued.

The filament used is FED Filament PLA 1,75mm Grey. My guess is its dry, as we store it in a dry environment and haven't got the same issues on our other Prusa and Ultimakers.

https://drive.google.com/file/d/1DZagJEVEFFo-DgmsFsXsJExfjc7rjv7i/view?usp=sharing

https://drive.google.com/open?id=1ewoYzNEI4hW2cQWd34KfwIGUdT7oIkzz