Prusa i3 MK3 Under Extrusion- First Layer Wizard
So I've recently received and assembled my i3 MK3 kit. And passed the first few calibrations / setup wizards. It’s when I attempt to set the first layer height that I’ve noticed a problem. There appears to be significate under extrusion.
When running the first layer wizard the first 40mm (of lenght) seems to be fine (starting in the top left corner) then the filament becomes very thin and appears under extruded.
The area at the front where the nozzle is primed seems to be the opposite- It starts thinner and then becomes thicker. I’m guessing there isn’t enough continuous presser in the hot-end? The filament I’m using is the included Prusa silver PLA 1.75mm.
Things I've tried / tested:
I will add photos shortly. Any helpful suggestions would be greatly appreciated. 😀
Re: Prusa i3 MK3 Under Extrusion- First Layer Wizard
First, do an e-step calibration, extrude 100mm of filament and check if it has really ectruded 100mm. This can be done with the "move axises" command in the settings menue.
If this is OK, you can check if vou have an cable break at the e-motor. This should not be persistant, if the printer is really new, but after a few month of printing, this can be an isse.
Thomas
Re: Prusa i3 MK3 Under Extrusion- First Layer Wizard
Thanks Thomas,
Will try and post the result.
Re: Prusa i3 MK3 Under Extrusion- First Layer Wizard
First, do an e-step calibration, extrude 100mm of filament and check if it has really ectruded 100mm. This can be done with the "move axises" command in the settings menue.
If this is OK, you can check if vou have an cable break at the e-motor. This should not be persistant, if the printer is really new, but after a few month of printing, this can be an isse.
Thomas
So I preheated for PLA (215C), measured and marked 110mm and then extruded 101mm of filament. The measured remainder was 8mm so nearly spot on. During the process I did notice a different set temp. The "First Layer Cal." drops the PLA temp to 210C.
The attached file shows the results of the First Layer wizard. I've only just noticed that it starts late too. Then seems ok for the first 40mm, then under extrudes and becomes very thin. This is repeatable and happens each time.
It has to be a clogged nozzle doesn't it?
Re: Prusa i3 MK3 Under Extrusion- First Layer Wizard
If you have successfully alinged your first-layer z-distance, do this test and show me the pucture :
https://www.thingiverse.com/thing:1657650
Yes, is a first layer test, but it also shows the uniformity of the extruded filament.
Thomas
Re: Prusa i3 MK3 Under Extrusion- First Layer Wizard
Thanks Thomas,
I'm not convinced that test will show anything other than under extrusion everywhere.
I also think the filament sensor isn't working. Not sure if that is related but I'll follow that up in another thread.
Now I'm guessing the extruder stepper motor is slightly out of alignment. It seems too far over the hot-end hole. The extruder works open without the spring tension screws or the gear on the other side of the filament. Without anything to compare with this is just an idea.
I will go back to the build instructions and try to work out whats happening.
Re: Prusa i3 MK3 Under Extrusion- First Layer Wizard
I had same problem. You have to decrease z axis in first layer calibration. This video helped me:
Re: Prusa i3 MK3 Under Extrusion- First Layer Wizard
Thanks for that. Lowering the height to about -1.1mm did improve it. It does print but there are some significate quality issues. I’ll check other posts, instructions and videos first.
The extrusion doesn’t seem 100% and I’m guessing it’s something to do with pressure / the Linear Advance system.
I printed the vase on the included SD card. It was over 8 hours and the outside looks greate but the inside shows several issues.
I think this thread can be closed and this can be mostly solved by lowering the nozzle height. I hope this info helps others.