I am having all sorts of issues with my print quality and I think I have traced it back to the extruder drive wheel skipping. I can hear and see the drive wheel skipping when my machine puts down its first layer and it results in a rippled first layer with tearing between the lines. Has anyone found a solution to this problem? I have contacted customer support multiple times about this issue and haven’t heard anything back in almost a week. I would like to just problem solve myself and then ask them for specific replacement parts since it seems they are incapable of helping me troubleshoot in a timely manner. Definitely not buying another one of these machines, and wouldn’t recommend any Tiertime products due to the horrible customer service experience. I’m not upset that my machine needs some maintenance but I am upset that customer service doesn’t give a fuck about us once we’ve given them our money. Please help, thanks.
I have two cetus machines and from my experience the above happens if the nozzle is not aligned with the extruder or the fitted nozzle is smaller than configured one. Check your slicer if the above is correct.
Regarding the support I have very opposite experience, I think they are very helpful and know their products very well. They usually respond in 48h during a working week. You may be unlucky due to holiday period but be patient and they will come back to you.
Check your printing temperatures first. There is a chance these are too low and therefore the filament can´t be melted…
@naturenate Did you get a reply? I have a similar problem with my extruder.
New Heater / new Barrel / new Nozzle and the drive is skipping even when i extrude material (during loading new filament)
that means it is not melting plastic as it should, have you got an infrared thermometer or any other equipment to check the temperature of the extruder? If it is not heating then check the wires maybe there is a problem with connection. I had a similar issues when I switched to V2 extruder heater and to print as before I have to change all printing temperatures up by 10 deg C. I think the problem we are facing in here is we have no control over PID so it would be great if Tiertime can give us this option in the software.
OK, my mk3 was shipped in 11/2018 it had the v2 heater but the old nozzles installed.
With that setup i printed happy over the last 3 years. Then i changed to the new barrel with the separate nozzle => that resulted in skipping drive.
Than i changed the entire heater with brand new barrel and brand new nozzle => skipping drive.
I raised the temp. to 215° still skipping drive.
Next i will clean my old nozzles and try again.
sometimes it is worth to check → this brand new nozzle, is it the same size as the old one and correctly set in the software?
Yes of course. 
Will also try the 0.6mm nozzle and even without.
Could it be a cooling issue?
I don’t think this is a cooling issue. I would temporary change settings to ABS and see if this improves flow through the barrel and if there is any PLA residue left inside it should melt and make it easy for fresh PLA to be extruded.
I changed to the old 0.6 Nozzle wich i never used => print without any problem.
Cleaned the old 0.4 nozzle => actually printing the second piece without problems so far.
I also cleaned the old 0.2 nozzle => will test later.
So its not a extruder problem, it is a nozzle / heater problem.
I am glad you are back to printing with no issues.