The problem could be a result of a bad stepper driver on the Mobo. Only problem is that the stepper driver is integrated into the mobo. If you have not already, contact Cetus support directly and submit a ticket asking for a new motherboard. I know of at least 2 people who have asked and gotten new ones because of driver burn outs. It is not common but possible to have this issue.
Look in where Jene says, I had the same problem and it turned out when I changed filament there was a tiny piece of old filament in there. It was impeding the flow of the filament giving me print flaws and the click. Cleaning everything out fixed it.
I will explain what the problem actuall is because I have spent 2 days troubleshooting all posible issues.
in short: ITS THE FAN/COOLING!
The fan is cooling the head to fast causing the filament to cooldown and click while exiting.
The only way i was able to fix this problem is to avoid using RAFTS and printing with VERY SMALL DISTANCE from the BED.
Another thing i noticed is the BED is not 100% leveled staight, its bent on 1 of its angles when placed on a straight surface
(dont know how this happened or if it was always like this)
This doesnt allow me to print close to the bed on its full area (I will have to remove it and use preasure to straighen it out).
I have since then printed without using raft because when rafts are printed the head extrudes a lot more filament causing it to click. Printing rafts on a very close bed/head doesnt work.
Also I noticed that the fan is not variable and also the temperature of the nozzle never changes while the temprature of the extruder is 96-100% variable. This is another reason to click because the fan is constantly cooling something that changes temperature instead of varying to stay consistent.
Questions to Cetus:
how do I know if the temperature of the nozzle is ok ? (i see 17oC before it changes to 35% after the print starts)
how do I change the fan speed
Are we getting any software updates for mac users soon?
2 main reasons why the extruder will click. 1 nozzle too close to the build plate. 2 nozzle too cold. You should be printing between 195 - 210 for PLA. I've printed as low as 190 and never had cooling issues due to the fan. Is the stepper motor warm to the touch? If it's cold this means not enough current is going to it, and could be the cause of the clicking also. Good luck!
Are you using the Cetus/Tiertime branded filament? Certain brand do have the clicking issue due to a heat buildup in the all metal head - thats why the redisigned it from the initial campain so it would work with more brands, but still not all brands work. Couple of things you can try
1/. Try putting an oiler on the filament (this solves for some brands)
2/. if you havent already, try another brand.
If you are using the cetus filament, ignore these as it should work without this, so this wont be the issue.
