Under Extrusion

[Micah Smith]

I've put about 30 hours print time into the printer, and it seems that no matter what setting I put the temperature/retraction speed/print speed to, I always get stripped filament. This is a problem now with every print. Starts out fine, but after 2 or 3 hours starts to strip and ruins my print. I'm printing PLA as high as 225c and still get the stripping. No clogs, either. Looks like the resistance might be caused by the stripped parts of filament getting jammed inside the tube before it reaches the hotend.

I've tried every suggestion and piece of troubleshooting advice, still without good results. All prints done on Cura.

I also notice that the top 5 or 10 layers before the stripped-filament-clicking-sound starts appear really grainy from under-extrusion.

I have only tried the filament I received from XMachines. Could this be the sole culprit?

[Sandro]

In a word, yes just the filament could be causing this.  Do you have a pair of calipers to measure the diameter of the filament.  Low-quality filament often has highly variable diameter.  I found a small (1" / 25mm) section of filament on a roll that was over 2mm in diameter.  It was visibly too large to fit through the tube.  Try some higher quality stuff and see if you get the same issues.  I've heard good things about Hatchbox (but I haven't used much of it myself).  I'm currently using Inland (it's only OK) for cheap things, and Atomic filament for better stuff.  I just ordered IC3D for the first time, it's spendy, but I hear great things about it.

I would also be extra super sure the bowden tube is fed into the hot end the correct amount.  At least one other Lorei owner had theirs in too far (I didn't think that was possible).

[Micah Smith]

I checked the Bowden tube and it goes in all the way, but not too far. Still didn't print well. Is it normal for the motors to get hot as well?

[Sandro]

A certain amount of heat is normal, they shouldn't burn you if you touch them. If they run hot enough to be slightly uncomfortable I think that's only barely OK.  Ideally, they would only be warm to the touch.

The current going to the driver should probably be turned down, especially since too much motor heat can cause jams/grinding.  Looking at the controller boards there are small potentiometers to adjust the current, but they look pretty fragile., so if you go this route I would be *very* careful with them.  I've seen people turn them so hard they ripped off the board.

Here's a generic tutorial on adjusting driver current:

http://matterhackers.dozuki.com/Guide/Tuning+Motor+Current/37

[Micah Smith]

I wouldn't say it's hot enough to burn, but it's pretty close to the 70c heat bed. This is the extruder motor. Maybe it's warping the filament as it enters the Bowden tube?

[Bob Kolbasowski]

Micah,

I had a very similar problem. To determine if it is a heat problem an east check is to place a small desktop fan, from the backside of the printer - blowing at the x-axis motor W the extrude. See if that works.

In my case it did, so then I used my flir to see temp at ~160'F. Problem is that depending on your config, you have 2 - 3 motors in same spot making a lot of heat. I placed 40mmx40mm heat sinks to those motors with thermal conductive epoxy and my issue has been resolved.

R,

Bob