Your thoughts about the new PICO hotend

It's the other way round. Molten PLA is like glue and sticks to everything. PLA past its glass transition is like rubber and has a high coefficient of friction on most materials, hence why PTFE liners are used.

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[www.hydraraptor.blogspot.com]

So it doesnt mix, or doesnt matter if it does, ideally then a dip after the bowden? maybe an oil hole in the tube? I've only done a few parts, not used oil, but am wanting improvements, I printed a raft yesterday, that came out perfect absolutely smooth...wish the top layer looked like that, the top is functional but ugly.

But couldn't a particular alloy be better at sticking to PLA than another?

The 3.0mm e3d v6 doesn't have a PTFE liner, and I have yet to run into any of the jamming issues with it that I had with the Pico. Maybe they're the same exact surface and material and it's all a matter of design.

The 'full' e3d v6 uses an aluminum heat sink and forced cooling, so it has a short transition zone in a very well designed heat break. As all metal hotends go it's probably close to optimal, at least in terms of having a chance of coping with pla. So far, every other filament I've tried is easier to extrude than pla.

The best hot end have I found for extruding PLA is the ex-RepRapPro hot end with one piece stainless steel heat break and nozzle and a PTFE liner in the cold end. The only time it jammed on me what when I was blown testing stupidly large values of pressure advance without reducing retraction. It tolerates 10mm retraction in my dual nozzle setup. In contrast, my genuine E3DV6 is sensitive to retraction amount and has clogged up several times. I haven't tried the E3D Lite 6, and it could be better suited to PLA and long Bowden tubes than the full V6 is.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

@ zachnfine: I think I may have the explanation for many of the so-called jamming occurrences.

I had my Pico coated a few months ago. In preparation for the coating, I disassembled it and did my best to clean it out. I noticed something strange. (My Pico is a 1.75mm version, Gen1)
It seems as if the long bore through the whole piece was drilled from both sides (not surprising, judging by the diameter versus depth ratio of the bore).
Where the two bores meet, there is a step. Either the bores are offset slightly, or the drill from the nozzle side was slightly larger (which is what I think). In any case, the step makes a standard "cold-pull" impossible. As soon as the filament has cooled somewhat, and you try to pull the filament back out, the portion of thickened filament, the 'plug' present at the transition zone, jams right at the step, simulating a PLA jam.

Earlier on, I would run into the same issues with frequent jamming - primarily when I attempted to do a cold-pull. I print PLA almost exclusively. I used to do the vegetable oil seasoning, too. It won't help the cold-pull jamming, though.

Now that I have realized where the problem lies, I have given up on cold-pulls and remove the filament while the hot end is still above 150°C. I haven't had any issues since then. Of course, getting the hot end coated may have also solved that problem, who knows, and I've stopped the oil 'seasoning', too, here the coating definitely helped.

But I definitely have a step in my bore that eliminates the possibility of a cold-pull.

I was just thinking about getting another Pico. Too bad they stopped making them.

mjh11

I have deltaprintr mini hotend on one machine and it has performed really well and it's miniscule in size. I liked the idea behind the pico but didn't buy one as it seemed a lot people had issues.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions