Auto nozzle scrubber

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Ryan_
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Auto nozzle scrubber

Post by Ryan_ » Sat Jun 11, 2016 7:28 am

I've been thinking about implementing an automatic nozzle cleaner brush similar to this bristle type: https://www.youtube.com/watch?v=mUeDcgkfJoQ or a pad like on Lulzbot machines https://youtu.be/Hx1q_GJC3_k?t=44 I'd imagine the bristle type cleans the tip more thoroughly.

This is a quick sketch of the potential mounting position for a bracket holding the brush and the dish to collect extruded filament when priming. Attached to the steel spider mounting plate (not on the spider itself because that'd mess with the leveling springs).
nozzle-scrub.gif
nozzle-scrub.gif (2.82 KiB) Viewed 6377 times
the G code at the start of each print would be to move the nozzle in line with the brush and use the Y axis to dwell over the dish, prime the hotend, then scrub the tip.

Any suggestions or improvements of this idea?

Are there dxf files available for the Spider Mounting Plate and spider, so I could design the bracket with appropriate dimensions? I can't find them on the makergear github

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ednisley
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Re: Auto nozzle scrubber

Post by ednisley » Sat Jun 11, 2016 2:25 pm

Ryan_ wrote:prime the hotend, then scrub the tip
An automatic nozzle scrubber would be wonderful for PETG, but cleaning the cleaner will be a problem.

Back in the day, a simple silicone rubber flap on my Thing-O-Matic did a nice job of cleaning the nozzle, but the ABS snot sometimes stayed on the flap. Returning over the wiper in the other direction to clean the other side of the nozzle would neatly reattach the snot blob to the nozzle. If I didn't remove the snot from the wiper flap after the print, the next time the nozzle came by, it would leave the wiper carrying two unsightly blobs:
https://softsolder.com/2011/05/11/thing ... d-splodge/

Image

I think a fixed brush / pad / bristles will have the same problem: whatever gunk wipes off the nozzle during one pass will reattach itself during the next pass.

If you can make it work for PETG, though, sign me up! [grin]

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Tim
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Re: Auto nozzle scrubber

Post by Tim » Sat Jun 11, 2016 3:07 pm

ednisley wrote:If you can make it work for PETG, though, sign me up!
Likewise. I've been wanting to experiment with better wipers. I did my magnetic coupled dual extruder mainly to get around the problem of nozzles dripping all the time when trying to do dual prints in PETg, but they still drip when not in use, so it doesn't really solve anything unless you can wipe each nozzle well when it goes active. If you find something that works, I want to know about it.

Ryan_
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Re: Auto nozzle scrubber

Post by Ryan_ » Mon Jun 13, 2016 4:40 am

One concern I have is how fragile the thin heat break is on the V4 hot end-- it can be broken if you don't remove it from the machine to change the nozzle.

Perhaps the repeated process of driving the nozzle over a brush will weaken and eventually break the hot end at the heat break?

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