3 year old Prusa I3 MK3 Extruder moter SUPER HOT
Hello! I have a the Original Prusa I3 MK3 model, and it's been going strong for almost exactly 3 years now with no issues. This thing has over 200 days of printing and close to 2500 meters of filament that have gone through it. I've had no parts fail, except for haveing to replace heat blocks, thermistors and a few other nozzle components a few times due to filament blobs in our early days of printing. I've got settings dialed in perfectly, and it prints like a dream.
About 5 hours in to a 30 hour print I was hearing clicking noises in the extruder assembly, so I loosened the bolts for the clamp on the filament and it that fixed it (I had tightened them a lot before because I had noticed this before when printing with PETG). I put my hand on the motor and was really surprised by how hot the motor was. I've noticed it getting hot in the past but not as much as it is now. The print is still going and is printing with PETG filament with the extruder at 230 and the bed at 85. The motor is noticeably hotter than the bed, and I'm fearing it's reached the 100 degree celcius mark that I've read isn't good for it. I'm also worried that it's losing torque and that it's losing its ability to pull the filament from above and push it through the heat block, thus the clicking. Also, this is in the IKEA Lack enclosure.
Long story short, the extruder motor is way hotter than I think it should be, very near or exceeding 100 degrees celcius. I'm planning on ordering some upgrades soon from Prusa, should I get a new extruder motor too? Any input is appreciated, I want to take the best care of my printer as possible, I love it so much and I don't want to hurt it!
-piranha250
RE: 3 year old Prusa I3 MK3 Extruder moter SUPER HOT
230C is on the low end for PETG. The hotend may not be able to melt it as quickly as your pushing it, creating back pressure on the extruder and thus the motor. Try increasing your nozzle temp 10C.
You should also do some cold pulls to be sure there isn't burn crud & carbon inside your hotend and nozzle, maybe consider a nozzle swap.
Be sure the extruder tension isn't too tight. If you see deep gouges from the gears after unloading, it's too tight. Be sure the extruder gear idler spins freely. Inspect the extruder Bondtech gears and PTFE tube for accumulation and damage. Make sure the filament feed freely without friction.
If your enclosure temp is 40C, that's at the high end of the E3D V6 rating. Since it's an air-cooled design, cooling efficiency will be reduced. Heat creep is less common with PETG but it can happen. If nothing else, extra heat accumulating in the extruder will contribute to temperatures. Try opening your enclosure door and see if it improves. Make sure there is airflow over the heatsink.
RE: 3 year old Prusa I3 MK3 Extruder moter SUPER HOT
@bobstro
Thanks for the tips! I realized that I gave the first layer settings, which are 10 degrees lower than everything else. It’s currently printing at 245 nozzle and 90 for the bed with the door cracked open on the enclosure. I think having the enclosure open a bit helped the most, so I’m definitely going to remember that for the future. With the bed at 90 I can definitely notice the difference in temp by touch compared to the extruder motor. Definitely going to get new order tubing on my next order. The motor temps are still a bit high, but I’m happy like that they’re not as high as they were before. Once the printer isn’t as busy as it is now, I’m going to print new parts for a lot of the extruder, in petg, maybe nylon and I’ll reconfigure the fan for better airflow. Thanks for the tips, they really helped!