Hey community, may I ask for your experiences with all metal hotends and PLA?

Hey community, may I ask for your experiences with all metal hotends and PLA? It seems it is a known problem that they can suffer from temporary clogs while printing. I got this with genuine hotends from the beginning over several different pieces. It is not related to retraction as it also occurs during long flat prints with stable temps and all that.

Did I just missed the fact for so long that all metals don’t work well with PLA?

Tried filters, Teflon spray, temps, filaments, cooling, force, magic.

And sometimes it just works for months. :frowning:

I’ve been working with this problem. The PTE liner insulates the PLA, keeping it below glass point. The all metal hot end heats the pla up and causes it to hit its glass point prematurely making a mess inside the extruder.

This is what I’ve read. What I experienced is that pla partly melts allowing it to bulge. Once it bulges, it jams itself inside the barrel and clogs the extruder. This effect is worsened if the extruder sits without it extruding. The filament has more time to heat up and partly melt/ hit it’s glass point.

I am currently, like right this minute, working on a water cooled hot end to serpent this problem. But for now, I am using PTE lined barrels.

@610GARAGE With proper cooling that most of the time is pointed towards, the heat shouldn´t come up that far. I mean it never clogged fully but mostly enough that the the max force available isn´t enough to ensure proper extrusion.

I also got more reliable results with PTFE liners and most materials I need don´t exceed 240 but I think this must be solvable with classic heatsink fan combinations.

It´s just a unpleasant feeling and wastes a lot of time if long prints fail because of a short extrusion stop.

That click sounds drives me mad when the first hour went perfecly fine :smiley:

I use a genuine E3d Volcano (all metal) on my core-xy bot: Have for the past few years…, and pretty much exclusively use PLA. Never had any problem with clogging during printing. In fact, nearly every clog I get is due to some issue in the filament, not the hotend.

@Thomas_Herrmann Oh, I know your pain only too well. Mine jammed every other print, if I was lucky for about a month.

From my experience, it does. Granted, every printer is different. And every filament is different, sadly. I was fine with direct drive, but when I moved to bowden setup, I had issues. RIght now, I have compressed air blowing directly on the barrel. I have a thermal image of this. You can see the heat moving up quite high. Sadly, the thermal program I am using is a bit buggy, so I can’t get an exact temp on the barrel.

Speed will also have a factor. The quicker you push that plastic through the nozzle, the higher the pressures. The higher the pressures, the more likely the filament will bulge and clog. Your best bet may be to attempt to pull out the jame in one peice to see what it looks like. When I did that to mine, I found a bulged plug every time.

P.S. I push my printer hard. One of the reasons I am designing a water cooled system. My thinking is, I can have a hotter nozzle and push the plastic harder/faster. :slight_smile:
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I have yet to experience a clog with PLA, and that’s with a really cheap printhead. I shouldn’t cast aspersions without evidence, but I buy expensive filament, and my coworker buys the cheapest stuff he can get off banggood, and he has tons of problems with clogging. I think filament with debris in it and junk on the surface of the filament is partly to blame.

@Eric_Pavey I think the bigger diameter and longer heating zone helps to lower the force needed and makes extrusion less critical. I might switch back to ,5 nozzles to test that.

@610GARAGE I had similiar problems with bowden (v6) and direct drive (Aero). The temp above the heatbreak is around 30 degrees most of the time on the aero and similiar on the V6 (at least on the outside). So it shouldn´t be heatcreep. I´m also printing mostly on the slow side with max 60 mm/s as it keeps everthing quiter and less demanding for the mechanics. Should be well in the limits of all components.

@John_Bump Is use mostly the good stuff from various manufactureres and even changed the supplier a few times. So I think my filament should be good. I had dust in mind the last time as there is also the CNC in the next room. I already tried a dust filter and while I used it it seemed better with the clogs but I wasn´t sure if it really helped or it just fell into a “clogfree period”.

I will try to cold pull a bit and get the dust filter back on as a test.

I too was wary of all-metal and such hot ends because I heard the same things but I’ve found my concern was unfounded. You need to make sure the heat sink is sufficiently cooled and that the nozzle is on sufficiently tight for a seal that doesn’t loosen. Like with E3D, make sure the nozzle back flat isn’t touching the heater block, heat the block to 285°C, tighten the nozzle to 3n-m then let it cool.

Pico got a poor reputation because their instructions called for an air flow design that didn’t ensure sufficient fan air flow was being pushed through the fins.

A dust wiper is a good idea for most filaments, but don’t use them on the rough textured materials like CF, glass fiber, wood, etc. Coarse infill probably helps clean out dust anyway.

I think filament oiling is bunk that causes more trouble than it’s worth. It may take a thousand hours, but it will eventually form a gross layer in the heater bore that insulates the plastic from the heat.

@Thomas_Herrmann I believe that’s the speed I was attempting when I was getting the jams. Now I’m at 90 mm/s. I do have two extruders though, with a lined barrel. But the dual extruders more needed because I am pulling off of a 55lb spool, and pushing the filament down 3ft to my printer. One pulls off the spool, then the other jams the filament into the hot end. I could see that helping prevent jamming. More force = more better. :slight_smile:

I also wonder if plastic composition has anything to do with it. Do some companies design there filament to have a lower glas rating to aid with adhesion.

@Jeff_DeMaagd I tried reassembling a few times with attention to all deteils I cang et. Maybe I have to repeat the assembly a third time.

The oiling thing is something I used as a last resort and I currently try to avoid that step on the new hotend.

@610GARAGE I got my spools on bearings rolling of easily (1kg). I once had the impression that printing faster solved the problems for some time. That maybe gets the filament into a nice flow and it doens´t have time to heat up.

Will try again. :slight_smile:

I have printed +10kg of PLA with a genuine E3D V6. I have never had a jammed heatbreak or nozzle.

Using E3D clone, here is my feedback on the subject : on the same print (0,1 layer height), I tried differents Cura parameters and each time I got a jam…still I decided to change from cheap PLA from geetchtech one a little more expensive…and guess what…no more jams…so definitly PLA quality is one of the key to jam free prints.

I’ve never had a clog with PLA on my genuine v6… I’ve had overcooking and occasional leaks, yes. The only clog I got was when a chip of PTFE fell into the extrusion path… And that was one clog over… Two dozen spools of pla?

So as a conclusion the only thing that is present that most of you maybe don´t have is the higher amount of dust (wood,gfk) in my working environment.

Oooooh yeah, that’s definitely going to have an impact. I start freaking out when I see flying fine plastic hairs get stuck in my fans on the nozzle, I’d rather not imagine what floating fine sawdust would do to them! One way to avoid the problem, maybe, is to do a reverse bowden (i.e. PTFE tube from a dust-free filament enclosure to the intake of your extruder), since that will keep the particles out of your extrusion path.

Also if your environment is dusty and your spools have been exposed to it for a while, consider adding a piece of sponge before the filament goes in the PTFE to try and keep the particles out, there’s a number of filament-cleaner add-ons on thingiverse you can look up.

I too am in a dirty environment. So, maybe that is it. However, I never had an issue with lined barrels.

I found the issue that caused the main extrusion problems. The bearings on the two aeros went rusty again and caused significant resistance for the stepper.

@Jon_Charnas I mostly use the “ziptied foam” approach :stuck_out_tongue: