When trying to push higher volumes of PLA on a @Printr_bot Simple, cooling is very important.
I forgot to turn on a supplementary cooling fan. Its job is to cool the top half of the Ubis and extruder assembly.
Came down to find the PLA packed into the hot end and wrapped around the extruder like I’ve never seen before.
Took a while to clean that mess up…
very glad to see some of the “3D printing pains” rather than just the usual “stuff works for me” posts i generally see these days
I will be pulling out y plastic extruder assembly from them this week now that I have a little time. I think a huge issue is the aluminum makeup of the extruder, but the hotend could use some cooking too. I found a nice printable fan mount that I use which allows for the print/top to be cooled. Has been working great, but I had the same issue and my extruder motor was overheating and skipping steps before as well
I think It’s also good idea to attach radiator(s) with thermoconductive paste.
How fast are are you trying to print? I’ve never had anything like that happen with my Simple before.
Also looks like you’re using the ceramic Ubis, suprised that’s pushing much heat up into the extruder to begin with.
I’m trying to get to 60mm/S. With my hot end at 205-210 I can get the extrusion volume up to ~10mm^3 / S and that seems to be getting close to the 60mm/S speed on a 300um layer height.
My setup is coming on 2 years old. Near the beginning I had to print a mount for a small fan to cool the stepper - seemed to be a common problem, as the part was designed by someone else. Once installed, I printed just fine at 30mm/S for a long time.
Oei!
That temp might be a little high for printing at that speed. I print PLA at 190 to 200 at 50mm/s. I up to 210 for 150mm/s and 215 for 200mm/s.
Interesting, I’m running at 60 mm/s myself and have had no problems, though I’m using the Ubis 13S. I never ran the ceramic that fast.
I’ve also never done a long print at that speed, I try to keep everything under the 2 hour mark if I can help it (I’m impatient). Makes me wonder if I’d start seeing similar issues if I do long duration runs at this speed.
Incidentally, mine isn’t a “Simple”. Mine is a highly enhanced Cobblebot. Just stating my experience with PLA temperatures.
@Greg_Nutt Double + on the “Cobblebot” LOL! Mine’s also “enhanced” https://www.flickr.com/photos/flyinglow/albums/72157649999302776
Looks like the tension nut on the idler is too high, try loosening it. That could account for the hot motor. Go as loose as you can but as tight as you need. That tight setting could be deforming the plastic and making it hard to shove the square plastic through the round hole.
@Brook_Drumm Are you seeing the Ubis ceramic ‘degrading’ over time? I have noted a need to increase tension, temperature, etc over the past year to alleviate jamming/skipping/stripping filament.
On other gears I’d run into trouble squeezing filament too tightly that it compresses filament, increasing drag down the guide.
Just talked to Carl and he said heater and thermistor don’t degrade. They can give out completely - I’ve seen it a handful of times. But no slow spiral. The barrel can get charred w plastic residue if filament sits in there while hot and it increases drag. A “cold pull”, preferably w nylon, will clean it out. If you run s lot of carbon fiber, the passage in the barrel can get scored or eroded. But it takes a while. The hole in the tip can grow when eroded w carbon fiber but it has different symptoms. The print accuracy will degrade and look like underextrusion.
Ok. Lots of variables to try and keep track of - will clean this one out best I can (I only run basic PLA - lately from a local supplier in town, so no carbon fiber and I don’t have nylon either). Will try running a bit cooler, and will definitely work out a more idiot proof way of keeping the cooling fan on (of course, that will just result in me becoming a bigger idiot, but ce la vie).
If you think it’s the hotend, I’m happy to replace for free. I can throw in a v2 extruder, but it looks like the added arm length may cause a problem. Send your address.
Brook at Printrbot…
The heater and thermistor don’t degrade, but the PTFE or PEEK in the hotend can.
Also stepper motors don’t get hotter under increased load, they actually get cooler. (assuming that the stepper driver’s Vref is not changed) Stepper motors are constant power devices, any energy that doesn’t get converted into mechanical work is becomes heat.
Agreed. I was just wondering if they turned up the pot to compensate for more resistance on the filament. Once tensioning is good, try the 60% setting on the pots and see how the motor feels. Not sure if you turned up the pot.
