Is lack of proper drying causing my extruder jams?

3D Printing
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Is lack of proper drying causing my extruder jams?

I started a new spool of PLA the other day- same brand, same color as the one I’d just finished which worked fine. I dialed in the numbers on the new spool and flawlessly printed a 2 hour, 6 meter part.

When I ran the same job again- the extruder jammed about 1/2 hour in. I thought I’d successfully unjammed it and ran the job again. About 1/2 hour in- another jam.

Is this jamming behavior consistent with insufficient drying?
I realized after I’d spent all evening fooling with the hot end that I’d neglected to dry the filament.

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I had similar issues recently and had to crank up the temp to overcome the jams. I’m convinced it was due to moisture absorption. I now have that spool in a zip lock bag with desiccant in an attempt to dry it out. I’m going to do some test prints this weekend to see if that resolves the problems I had.

3

Hi Roger - I had similar issues until I added a cooling fan to the extruder.

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@Jason_Bowling yeah, you pretty much cannot print PLA without a cooling fan on the E3D. I don’t understand why so many people think they can just simply leave that part off…

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I don’t have an E3D. I have an Ubis hot end on a printrbot. I’m confident extruder cooling is not the problem. I’ve done a good amount of printing with good results and no fans at all.

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Mine was a Printrbot Simple. Perhaps it is only needed on some filaments, but it sure needed it on mine.

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FWIW, I already had a fan on my extruder and had numerous successful prints prior to the issues. When new, I was printing with the same filament at 185 and then eventually upped it to 200 and am now at 215.

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Where is the filament jamming? Taking close ups of the jam, the damaged filament and even the print can help us help you. :slight_smile:

I’ve had jams on my Simple (w/ aluminum extruder) from three things:

  1. Extruder current too high causing excessive motor/gear heat.
  2. Putting too much tension on the filament with the idler causing the filament to flatten/deform.
  3. Printing too fast. This creates too much back pressure and heat at the hobbed gear and the filament buckles.
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I’m beginning to think print speed may be the problem. I’d been experimenting successfully with increasing print speed when the old spool ran out. Now that I’ve got a new spool loaded, I’ll see what reducing back to my original speeds does. That could explain why it runs fine for 30-ish minutes and then starts to struggle. The first layers run more slowly, then the speed clicks up and the effect grows until it reaches the failure point.

I’ll also cook my spool for a will before I go any further

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I’ve noticed that I am able to print faster with higher extruder temps since the PLA is softer at the nozzle … It has the added benefit of smelling more like waffles… Mmmmm, waffles…

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I love the PLA smell, too. None of the rest of my family do. But that’s probably good. We don’t need little ones getting their noses bonked by a suddenly moving extruder when sniffing hot filament.
That would probably hurt. I guess it would hurt. I don’t know from experience. I’d NEVER do a thing like that…