RE: More clicking, no extrusion
[...] I haven't played with de-retraction... but I have calibrated my steps/mm, which should get the flow just right. I'll have to pay with MVS... I just don't have the time now, or for the foreseeable future.
Ah, sorry. Didn't mean to conflate MVS with retraction. I was just noting that in testing MVS I noticed that PLA flows very differently than PETG in addition to the obvious temperature differences. It "doesn't like being rushed". Testing MVS probably won't help much with this issue, but I would try reducing deretraction speeds.
and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
RE: More clicking, no extrusion
Recently after a massive 3D print session making a 3D sets Landrover my printer started making the click-click-click sound in the extruder head.
I’ve had my Mk3s for nearly 18 months and have done over 2000 hours of trouble-free printing. The clicking sound is simply the filament not passing through the nozzle and the extruding gears slipping on the filament, sometimes reloading the filament helped and maybe a cold pull. The actual solution is very easy.
First don’t change any settings, the printer was working fine before, if you change the settings you are not fixing it you are just hiding it. Also don’t think this is a good time to “upgrade” parts. The Prusa PID controller was designed to work with an aluminium heat block and brass nozzle unless you are willing to alter the PID settings the standard parts are adequate.
The only thing I changed is the thermistor. Thermistors are not really good at high temperatures typically there are not used in situations above 150C. For engines, we use PT100 and thermocouples to monitor exhaust gas and cylinder head temperatures on our marine diesels, and they can handle the higher temperatures and give a predictable resistance or voltage based on the temperature provided. I found in the past that thermistors have a working linear range that degrades over time especially with high heat applied. The range changes and whilst may only be 5 degrees off at 150C might be 30 degrees off at 200C. This is the difference between the PLA being plastic and solid.
If you live in the UK E3D supplies the hot end for Prusa and the prices especially shipping is a bit more reasonable. I replaced the thermistor but also the block (mine was really baked with filament) and the heater cartridge (the wires were frayed). But really all you need to replace is the thermistor.
Use the Prusa manuals and reassemble as you did when it was new including the thermal paste on the heat-brake threads. Once assembled hot tighten the nozzle. I did the temperature calibration which passed successfully. Finally, I did the first layer calibration and printed a Benchy.
The printer has done about 6 hours since the replacement thermistor and is printing reliably again.
RE: More clicking, no extrusion
Hello. I have same problem Prusa MK3 works perfect and prints everything - in hot summer and cold winter and with many retraction moves. After 2 years I get same problem. From month I can't print anything... Service are not helpful in this case.
I change HeatBreak to E3D original (+ thermal paste of course) , PTFE Tube, new E3D nozzle and new Thermal sensor.
Nothing helped. After start print on PLA or PETG - print stops after 1-2 hours. I turned off retraction and still not working...
That is crazy situation. Next in plan is change fan to MF40101V1-1000U-G99 (recommended by bondtech) and reasemble all parts with new better thermal paste. If it doesn't help - I will change all to bondtech extruder.
I'm curious why prusa works perfect, and after 1,5- 2 years will stop printing. 😤
RE: More clicking, no extrusion
Applied #3 (and perhaps also #2) and it solved my problem completely. The issue was happening during printing litophanes with too many small details causing filament retractions.
I could stop the clicking doing these three actions:
1- thermal paste on the heat sink thread.
2- more pressure on the tension screw (the references for the position on the MK3, MK3+MMU2, and MK3S are differents).
3- changing the retraction parameters to:
Length: 0.4 mm
Lift: 0.2 mm
Retraction Speed: 20 mm/s
Minimum Travel After Retraction: 10 mm. After I tried to reduce and now is all right with 2.
There are now more than 10 days without problems with 10h of prints every day.
In the next days, I will try to return to the standard values.
RE: More clicking, no extrusion
Thanks for this post. I had the same issue. I took out the opposite gear on the extrusion motor so I could look in to see the alignment of the gear on the extrusion motor. It was just off ever so slightly from centered on the filament. I would not have thought that tiny little amount of miss-alignment would have caused an issue. I loosened the set screw on the gear and moved it probably about 0.1 or 0.2mm That is all. A very, very slight amount but the teeth were now clearly exactly centered on the filament. I reassembled the extrusion head and now everything works perfect. Lesson for the books, this alignment is VERY sensitive!