Extruder CLICKING - What worked for me :)

Snapmaker J1/J1s
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First: Let me say that I love my J1s!

I’ve been experiencing the same extruder issues as many others on this forum and FB Group. Here’s what’s worked to resolve my issues:

1- SPEED - The printing speed needs to be lowered. I’ve successfully printed PETG @ 60mm/s for several 18 hour prints (over double the speed my old printer was capable of). No clicking with everything stock (as-delivered). Brands: Snapmaker, Overature, and Sunlu. All prints in copy mode. Other filaments (PLA and TPU) clicked and under-extruded badly. This was the reason to investigate further…

2- TEMPERATURE - I like to print everything hot to begin with. That being said, no issues with printing the PETG listed above at 235C. It seems that this printer likes the filament temperature on the hotter end of the suggested range. I’ve seen where users have reported colder temperatures helped with their problems. Not sure what to say but, that’s what worked for me.

3- THERMAL PASTE - There’s several mentions of adding thermal paste to the hotends in this forum. Thanks to all that contributed! I used the MX4 to the heat break-heatsink and Slice Engineering Thermal Paste to the thermistor.

4- NOZZLE - Replaced the stock nozzles with E3D MK8 0.4mm nozzles. The idea was mentioned in this forum (again, Thanks!). While there was no mention of this brand, I’ve had good luck in the past.

5- EXTRUDER GEARS - Replaced the extruder gears with Bondtech 1.75mm/5mm gears. The stock idler bearings were not smooth and as others have mentioned, the stock gears’ filament teeth are not as sharp (again, Thanks!).

6- FILAMENT SENSOR SPRING SPACER - REMOVE - This was mentioned in this forum (again, Thanks!). Remove the spacer between the spring and sensor body then re-assemble. This removed some of the filament tension. My extruder body was polished from the filament passing by and the excessive pressure exerted by the spring. I plan to investigate this further and source a lighter spring.

Here’s some other things I’ve noticed while using the J1. They’re not related to the extruder but do help overall quality.

1- EXTRUDER LEVELING - When setting the RIGHT extruder to the same height as the left, carefully tighten the screws while the screen is still showing the position slider (the green bar that moves relative to the nozzle height) and the print bed is bouncing up and down. While the extruder mounting system is capable of holding the hotend securely, it’s not straight when loose. See for yourself! :grinning: I found that I had to tighten and re-adjust 2-3 times, each time I removed the hot end.

2- LINEAR RAIL GREASE - This is another topic shared on this forum (again, Thanks!) but Here’s some more specific information for US J1 owners:
X-Rail - Amazon sells 3ml syringes and 18ga blunt tip needles. Y-RAIL - Amazon sells 3ml syringes and 16ga blunt tip needles. Also available on Amazon is NLGI 1 grease. Not much grease is needed but grease both locations as noted in this forum (again Thanks!). The rails on both my J1s were noisy and now they’re quiet.

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Excellent information, much appreciated. Pictures would help those of us less knowledgeable and would like to get there. Thanks again for the info.

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Agree on pictures. I bought the Bondtech drivegears but am not quite sure how to install it.

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You need to remove the extruder motor to get the gear removed. Remove the covers on both sides of the hotend. Then, two of the motor screws are visible. The third one is behind the filament sensor, the fourth is cleverly hidden behind the metal pin the flap for the extruder sits on - you can pull that one out of the plastic rather easily. Be careful not to scratch it.

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One thing I forgot to mention: I printed new filament holders for behind the machine. Available here: Filler Remix - Snapmaker J1 Filament Holder Mount by ChrisUFO - Thingiverse

Use 608 bearings for the roller. This is not mentioned on the page.

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Besides the reasons well listed in post of @drv7aa I’d like to share my experience in fighting extruder clicking.
If your extruder clicks from time to time and no visible signs of underextrusion are noticeable, the most likely step motor on extruder is having hard time move filament - it is working on edge of it’s power capabilities thus loosing steps from time to time and creating typical noise.

  1. Check if filament can freely move from coil to extruder. To tell the truth filament path on SJ1 from coil to printhead is a tough one - too sharp bends in relatively long tube creating excessive friction so exposing extra load on stepper too.
  2. If plastic with fillers is used (CF, GF, mineral or metal additives) it is better to move from 0.4mm nozzle to a 0.6mm one. This will allow molten filament to flow more freely through the nozzle. This is especially true with CF and GF filled filaments due to their specific rheological properties.
  3. Increasing printing temperature seems the right move to make filament flow easier and is widely used but there are at least two significant drawbacks in this approach: a) harder to control dimensional tolerances of print parts where assembly fits are to be maintained - overheated filament is less controllable, b) surface of print might become unpleasantly mottled, this is especially true using glossy filament - parts of external perimeter will have different gloss depending on speed of printhead in particular place of trace. Needless to admit rest of widely known drawbacks using too high printing temperature.
  4. Lowering printing speed in fact is the most right way to go to let heater block capacity meet the demand of molten filament. When filament is being fed, internal surface of nozzle is being cooled down by fresh filament and real temperature of filament exiting nozzle is lower than the one thermal probe is measuring on heater block. In case of steady filament flow heat exchange balance is stable and determined by heater capacity, hotend material properties and construction of hotend so you simply can not push more filament through than power limit of your stepper motor allows.
    At the same time it is not necessary to slow down the whole printing process! Just observe what are parts of layer where extruder starts clicking. The most likely it will be internal perimeter or infill - elements of layer normally being printed with the highest speed still at 100% flow. Gradually slow down printing speed for 1-2% at a time, let process (thermal balance in heater block) settle for about 10 seconds and listen again. If extruder still clicks - make another step of slowing down until extruder clicks are gone. Make a note on relative printing speed now - let’s say you have stopped speed slowdown at 92% or -8% of initially sliced speed. As you now know what part of layer the clicks were happening, go to your slicer and adjust that particular speed parameter reducing it for the same amount of 8%. This approach has the least impact on overall speed of printing yet keeping extruder stepper at it’s top capacity but not exceeding it.
  5. A little risky approach but working too - set flow a little less to avoid loosing on print speed at all. Flow down to 98-99% might help to get rid of extruder motor clicks yet not ruining mechanical and visual properties of print. Still a bit risky approach and not to be used on mechanically stressed parts.