Extrusion stopped before the end of the layer  

Re: Extrusion stopped before the end of the layer

OK, back to basics.

I flashed latest version of the firmware, restarted a calibration (went fine), reset all parameters (using M502), and restarted extruder calibration.

I'm extruding Prusament PLA at 215°C, 100mm each time at 100mm/min, with M83 command sent before.

Result are I'm constantly under-extruding, but the amount always change : between 14mm and 8mm. I have tried to tension the extruder bearing like mentioned in the official prusa video, by opening the door, extruding and tightening the screw until the extruder catches the filament. I still have the same issue.

Shouldn't the extruder be precise down to the millimeter or is it normal to have such fast differences ? All things considered, that's a between 14% and 8% of difference, and it varies randomly.

Thanks for your help,

Re: Extrusion stopped before the end of the layer

note the depth of the tension screw for the single screw 3s version. the other end where it is exposed in the idler will be almost the same.

keep working with this same tower gcode and slightly tighten the tension screw until the start of each level starts to look normal (just a faint short vertical line where the level starts.

Re: Extrusion stopped before the end of the layer

Hey, thanks for your answer.

As I knew my extrusion was incorrect, I worked on this yesterday, and found exactly what you are mentioning : the tension on the extruder-idler was not sufficient.

I started some extrusion (100mm each time) and tighten the extrusion idler until I got a consistent extrusion. After some tests, I found out that the default extrusion steps per mm let to _exactly_ 100mm of extrusion for 100mm asked, so that's perfect.

I'll retry to print the calibration tower and see how it goes.

However, this video is a bit misleading :

If you do what's said in the video (starting at 57s), then you'll ended up with an extruder idler not tighten enough, and to inconsistent extrusion. So the extruder is visually different from the MK3s version, but as the rest of the video is applicable, and this video is referenced as a nice source of information for bad prints, I found it interesting to mention it.

Maybe a note in the video saying this doesn't apply to MK3/MK3s would be a nice addition.

Re: Extrusion stopped before the end of the layer

Ok now that's waaaaaay better. There's no missing gaps in the tower and the tower looks good !

I have an additional question : there's no a clear vertical line in place of the gaps before. My assumption is that the extruder was starting and stopping at this place, leading to a little bit too much on material being extruded. Is this the real reason of this vertical line ? Is there a way to avoid it ?

Thanks for your help !

Re: Extrusion stopped before the end of the layer

so glad that you have this sorted.

you can assign a random start position for each layer and see if you like the look better but I personally would be happy with that result you have now...

I agree the getting started video needs an update to add the MK3s extruder adjustment...

Re: Extrusion stopped before the end of the layer

Ok, I'll try to play a little bit with the random start point, but if you say the current result is fine, I'm fine too 😀

Thanks a lot for your help ! I guess it takes time to know well the different part of a 3D printer, but little by little, I'm getting there !