A recent blog post from my good friend Michael Hackney about using oil in all metal hotends.
OK Jim, you click-bated me.
So when I stopped oiling after a year of good prints using it and then got my first clogged nozzle two weeks later, was that was down to too much retraction rather than not oiling? Hmmm… it’s a convincing article but…
Do the “all metal” hot ends have the same PTFE tube in that the FLUX head has? In other words, is the FLUX hot end “all metal” and if so, what is the maximum retract distance for the FLUX head I wonder?
I don’t think you were click-baited, you don’t even have an all metal hotend…
Your first clog after a year is actually kind of an anomaly with the FLUX, but you are making your oiler sound like a Lucky Bowling Shirt… A year of printing can and probably has led to plenty of wear in your hotend, especially the nozzle itself and the internal PTFE tube.
To answer your other questions, all metal hotends do not have the tube, so no, the FLUX is not an all metal. Not even close. I may actually have the only all metal FLUX toolhead at the moment and this article definitely did give me some good clues, as it did not occur to me that I need to put together a whole new settings group for it, but it makes a ton of sense and in testing I am seeing exactly what the author described. Reducing retraction… yep, seems obvious now.
As far as maximum retraction on the FLUX, I’m not sure, it can go pretty far and pretty fast. I think the most I’ve ever pushed it was around 12mm at 60mm/s though and I doubt that was making it work at all, but I also can’t imagine why you would need more than that either. (Even that was overkill, I had wrong temp and movement speeds)
These days, I barely ever touch retraction, it’s usually somewhere around 7-9mm at 30-40mm/s I think. That’s with the standard FLUX toolhead.
Changing that might be just the thing I have been trying to figure out with the all metal hotend.
Oh, and as far as oiling, the latest research I have seen is that as long as it isn’t messy, there may be some usefulness to it in terms of helping the nozzle (not the whole hotend) to a very tiny degree, and possibly some changes to part strength with organic oils. I’ve been looking for more objective testing but haven’t really found anything good yet. I did put mine back on for a few prints with an older spool of filament and a very tiny bit of coconut oil. I can’t say 100% that it helped, but it definitely didn’t hurt as prints came out perfect.
Thanks for the explanations Booze. I will continue using my lucky oiler with PLA then as it makes me feel good if nothing else.
It’s not hurting anything, and anecdotally might be slightly increasing part strength with vegetable or plant based oils.
If you pull the filter/sponge out and look at it, there is no doubt that it is removing dust and debris that would otherwise end up inside the machine, whether that would make much difference is hard to say but again, not hurting.
That article was aimed at a different bit of logic. Some folks incorrectly assuming that with an all metal heatbreak the oil is needed for lubrication. Fact is, the point of the all metal is the very short transition zone and about 80%+ of the heatbreak is kept out of melt temperatures. Oiling in that scenario potentially can cause more harm than good by allowing heat creep and blurring the distinction between the hot/not-hot zones that make the all metal system function.
No spam intended, I think it’s useful information to be aware of, whether it’s directly applicable or not. Between 7 of my printers with different hotends, the problems that people solve with oil have always seemed to be treating symptoms (to me, anyway) and not the actual cause in my experience. There’s no anomalous reason that some people have good luck with it and other don’t, the hardware is the same, so a wilder variable like material manufacturer or slicer settings is probably to blame. Whether a hotend is all metal or not, I think that settings or construction are usually to blame instead of a lack of lubrication. Raising the temp, lowering the speed, or solving issues with filament constraint are more permanent fixes. Filament manufacturers and injection molders never speak of oil, it’s a special home brewed solution that’s unique to printers. Printing isn’t fundamentally different than those other molten plastic processes, it’s just being used by a new audience.
PLA is certainly more susceptible to retraction jams than other plastics, all metal or not. The material has a different thermal coefficient, and it tends to pre-heat and wick temperature more then other materials, so pulling material from the melt zone to the cooler transition zone of the hotend with a long retract will cause melted plastic to solidify inside of the hotend, and is definitely something to avoid. Especially on a bowden setup, you’re not able to pull filament back through the nozzle, only to relieve the pressure that’s on it, so long retracts don’t really buy an advantage. I’ve had more than one part jam running the same GCode because of this, and lowering the retraction to something more like 3mm at 30 helped in those cases.
Anyway, I won’t tell anyone not to use oil, just that there might be other variables at play that you should consider as well. The right thing to do is what works for you, and nobody can argue with that.
Voodoo or not, it helped put me on the right track toward dialing in Phoenix Leaky.
I had not thought about changing retraction and how the new hotend would behave.
So it definitely was worth posting!
I’ve stopped using magic oiler after hardware update.