nozzle got clogged


this is about my 6th print and it stopped extruding in the middle of a print. Applying some manual force to the plastic (i tried enough force to bend the axis a bit, not going to do more) it will extrude a tiny bit consistently, but it won’t unclog.

What do i do about that? Push a 3mm rod in there? I’m worried about damaging something.

Btw anyone else has the experience that support@lulzbot is basically useless since they never respond? Their phone support is amazing, but calling from europe is really expensive.

They reply pretty quickly to me. Check your antispam folder?

The nozzle usually not going to actually be clogged unless you are running crappy filliament. Check your idler arm tension springs, there should be 8mm between the two washers on either side of the springs. Also check the small gear setscrew.

You will also want to get a cheap point and shoot infrared thermometer from your local tool or auto repair store ($35 U.S.) and check that the heater core is close to what it thinks it should be.

You will also want to open the filliament chamber, clean all the plastic out of the hobbled bolt and any shavings. Cut out and remove any sections of filliament with ground out c shaped sections in it.

Now move the nozzle up off the bed, heat to temperature and extrude 100mm or so. If it is extruding fine there, but not when you stay a print, you are either too close to the bed, or overextruding. Or the part is lifting off the bed. When you extrude molten plastic, it is essentially a noncompressable fluid. If the nozzle tip is blocked by being too close to the bed or by the solid layer ending up too close to it because of overextrusion or lifting, it basically is the equivalent of trying to extrude through a brick wall. It causes the solid filliament to come to a stop, which makes the hobbed bolt cut a c section out of it, ruining your print.

An actual clog is exceedingly rare, all evidence to the contrary. If you think it really is a clog, heat the nozzle to about 160, just warm enough to be able to pull the filliament out manually. Undog the extruder latch and gently but firmly pull the filliament out of the hotend. If it wont come out, bump the temperature up a few more degrees and try again.

The hotend barrel fan - the small blower - might be on its way out. It could be on and spinning but just not pushing enough air across the fins to keep the barrel cool enough which means that heat creeps up the hotend warming up he filament which then can clog up the whole thing.

It sounds like you need to do some cold pulls. If you can get some extrusion then it is ‘near’ clogged, but with some work you might get it opened up again. I would not push a rod down into it, I only use a piece of filament to check the barrel of the hot-end. Usually with the nozzle removed. :sunglasses: