Extruder clicking - wind idle screw in or out?
If the idler is clicking, should the adjustment screw be wound in or out, or is it not possible to say?
Background
Hi Folks, I've been very fortunate with my Prusa Mini. It arrived at the end of April and has run at least 60 jobs. Once I had stabilised my -Z over a period of time it has been pleasingly reliable. The recent build means I avoided the problems of early builds, which is good for a novice like me.
About two weeks ago, I heard occasional clicking on the extruder. I followed past forum advice on diagnosis. There were no blockages in the Bowden extruder or in the hot end cavity. The gears on the extruder looked clean. I vacuumed the chamber anyway. Finally although the idler screw seemed roughly level with the casing. I wound it out a little and back again until it was level with the top. After that, the clicking stopped and all was problem-free even though I hadn't really changed anything.
Now may I request your advice. Today I heard the clicking again, quite pronounced and occasional, not continuous. The Bowden extruder gears are clean. The print was usable but the quality was not as good as usual. The top surface of my print looked a bit lacking in material, which I guess you call under extruding. The base is good and sides are a bit rough with visible lines. The extruder gears look clean. I will next try the idle screw adjustment. Is it possible to tell if the screw should go in or out given the clicking?
A related clue may be that, just recently, filament loading and unloading continues to work but instead of changing colour on first purge, unless I move quickly when the printing pauses, it still works but sometimes takes three attempts for the new filament to appear if the printer has cooled from the previous print job. Before it changed colour first time, hot or cold. Now it only changes if I make the change immediately when printing is paused. But it works and the process is repeatable, and there are no clicks during the filament change.
Thanks for your advice.
RE: Extruder clicking - wind idle screw in or out?
Did you give this a try already?
https://help.prusa3d.com/ja/article/clicking-extruder-under-extrusion-and-clogging-mini_112018
RE: Extruder clicking - wind idle screw in or out?
Thank you, yes I went through exactly this procedure last time. As it didn’t reveal anything I thought this time I would start with the idle tension screw first. This is why I am asking if the clicking means the Bowden grip is too loose, or too tight, or if it cannot be directly linked to either situation.
I’m keen to get going again so I think I will again follow your advice and follow the under extrusion correction procedure in full again.
RE: Extruder clicking - wind idle screw in or out?
@ken-surplice
Whenever I had the clicking, it went together with severe underextrusion and what I suspected to be a hot-end clog. Moving up the heatbreak resolved it for me... Hope you have more luck with trying again.
RE: Extruder clicking - wind idle screw in or out?
Thanks again. Lesson learned and I needed your nudge to stop looking for a quick fix. The lesson is “no matter what may think, simply follow the corrective procedure”. I started with two cold pulls, one of which produced a different co,our filament that must have been triggering a clog. Then I followed with a vacuum of the extruder. When I print the same model I was printing before, the click is gone. My heatbreak is well positioned, perhaps due to it being a recently produced Mini. Cheers!
RE: Extruder clicking - wind idle screw in or out?
My brand new Mini clicks, but only when the extruder retracts and resumes. Basically, a double click that always coincides with a Z lift.
I'm not having any printing issues and I don't think I have any clogs since the unit is brand new.
I'm wondering if the clicks are coming from the gear lash? There was a bit a backlash between the gears and if I rock the gear back and forth fast enough I get can produce clicking sounds when there was no filament loaded. I took the extruder apart and tried to remount the stepper closer to the gear to tighten the gear mesh, short of binding the gears. The result is the clicks are much quieter, but is still there during the Z lifts.
Is the geared extruder supposed have no clicking sound at all?
RE: Extruder clicking - wind idle screw in or out?
I minimized the gearmesh even more, to the point where I can't rock the gear when no filament is loaded. The stepper still turns without straining and there isn't more gear whine then there was before.
No more clicking!