Any reason why PLA would print just fine then all of the sudden not

Any reason why PLA would print just fine then all of the sudden not go through the hot end at all? Seems like I need a tractor to push the filament through the hot end even at 240c. I’ve cleaned the bolt and tried to clear the chamber but it hardly spits anything out. Yet it’s taking feedstock into the chamber. This is the same filament I’ve been using for a while except the last stock was ABS and I purged all of the abs out of the chamber.

sounds like the nozzle got blocked!.

Why dont you try to use abs again, see if it extrudes. If it does, extrude a lot and then do a deep clean with acetone.

What happens if you heat the nozzle to 100 and pull the filament out?.

Ill try that, acetone won’t hurt the peek or ptfe? In the hot end?

Jeremy, you have to disassemble the nozzle and only clean with acetone the brass part.

But first, try to use abs.

Ok, it’s a j-head MKV-b hot end. Means I should probably take the heater and thermistor out too huh? This is going to be fun.

In addition to the possibility of a clogged nozzle, check the diameter of your filament and make sure that it hasn’t gone out of tolerance. I’ve seen 3mm-nominal filament that was ~2.9mm for most of its length balloon up to 3.3mm and jam in the barrel.

Ill check that as well.

Heat it to 70 degrees Celsius. Retract the PLA in one go. Typically pulls out all the dirt. And put a little piece of sponge on the PLA filament before it enters the extruder to clean it from dust while printing. Problem solved.

There are stories around of people finding little stones or ball bearings in the nozzle. They come from bad fillament.

Ya I found the clog and was able to remove it, was a small wood sliver, and a few very small chunks of old ABS feedstock.

Great! Glad you found the problem!

Now I’m just having issues printing what I assume is a hard gear to print in the first place.