Cleaning the hot end on the fly

Guys hi again.

I was wondering if there are any ways to clean a hot end while it is attached to the printer ? I was wondering if some drops of acetone would do the job ? My printhead is not clogged but i need to clean it every now and then .

Thanks in advance,
Pavlos

One way is to heat the nozzle to an appropriate temperature (about 100C for PLA), slowly retract the filament, cut off the end, and re-load the filament. The retracted filament brings with it any debris in the nozzle.

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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].

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dc42
One way is to heat the nozzle to an appropriate temperature (about 100C for PLA), slowly retract the filament, cut off the end, and re-load the filament. The retracted filament brings with it any debris in the nozzle.

Is there a risk of pulling the lining out of the extruder or otherwise damaging it when doing this? For example, in a E3D lite6 where there is PTFE tubing all the way down.

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See my blog at [moosteria.blogspot.com].

I've used this on an Ormerod nozzle with a PTFE liner - in fact this approach was recommended by RepRapPro who supplied the hot end kit.

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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].

That is the method that i am using . One day by mistake i retracted at high speed and i saw that this worked too. Some days ago i saw in a youtube a video saying that you have to retract at high speed and to tell you the truth i confused....!

Anyway for now i am retracting at low speeds and it seems to work pretty well.

The problem with retracting at high speed is that if the hot end doesn't have a PTFE liner (e.g. E3Dv6), then it brings molten filament into the cold part of the heat break and tends to jam. So the first 20mm of so of filament should be retracted slowly.

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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].

David do you know a good temp for retracting Abs ? I am now at 175c but i think i can go lower than this.

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Gaou
David do you know a good temp for retracting Abs ? I am now at 175c but i think i can go lower than this.

No I don't, however the glass transition temperature is 105C so I think you may be able to go as low as 150C.

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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].

Don't know about retraction for cleaning purposes, but my only tip for filament removal with all metal hot ends is extrude an amount say 20mm then the moment it stops manually pull the filament briskly out so that it doesn't get chance to cool and 'bond' to the heatbreak throat on the way out.

Has anyone implemented a cleaning area for the nozzle to move to to effectively wipe itself before moving to the first coordinate and beginning to print. Slow continuous retraction taking place between the cleaning station and the first print coordinate should prevent ooze during travel without pulling hot filament back up and into the throat? 2D printers have nozzle wiping as part of their 'start gcode' which seems like a good idea.

I just pull out the filament. Sommetimes slowly. Other times fast. Sometimes at 100c ish (atomic cleaning) other times just at printning temp 210c ish.
Never had any issues with plastick Getting stuck in cold end/heatbreak of my E3Dv6 full (metal).

No need to overthink it.

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