Cooling with an air pump?

I think you can get a complete mini hot end for $49 but if you're in the UK, it works out about £80 inc shipping/taxes.
They do spare parts. If you are UK based let me know if you're ordering something I'll split the shipping with you I want a spare nozzle and some of their newer silicone boots for this hotend.

Edited 1 time(s). Last edit at 02/06/2017 05:41AM by DjDemonD.

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Simon Khoury

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

I will get back to you before the end of the week. At the moment am still trying to make decisions on the moving bits of my new printer but hope to start thinking of other bits soon.
Mike

I like that hot end, but the small heat capacity worries me a bit.
Best thing I like about it, is the fact that it moves away from the Groove mount.

Never liked the groove mount, it makes things so cumbersome.

Lykle

Yeah I'm not sure anyone every liked groove mount, but DC makes a point, if you've got a pillar drill or steady hands just drill and tap the heatsink.

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Simon Khoury

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

I have been wondering if the Berd Air ring, good as it is, perhaps introduces a problem. Earlier experiments with two nozzles showed that they blew the filament about if doing bridges and this may also be a problem if there are too few holes - if there are lots of holes why not a slot?



Picture below showing how it was done with a Proxxon hand tool mounted in a lathe



I have no idea if this will work and won't be able to try it for a few weeks but will report back when I have tried it.

Mike

p.s., o_lampe, the bending was done with kiln dried sand.

Edited 1 time(s). Last edit at 02/08/2017 01:06PM by leadinglights.

Based on recent experiments, I think the slot needs to be narrower compared to the tube diameter. I made some printed rings similar to what you have done, and all the air escaped from the side nearest the air inlets

I design this pumped air diffuser for a E3D Cyclops hot end for a H-bot I'm building. Haven't printed it yet, still trying to decide on what type of air pump to buy. The inlets pipes are sized for silicone aquarium air tubing.

Hmm, Brian is using the pump at 25% PWM, this gives enough cooling and does allow for some nice bridging.
He uses simple holes in the ring around the nozzle.
Pics coming soon

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JamesK
Based on recent experiments, I think the slot needs to be narrower compared to the tube diameter. I made some printed rings similar to what you have done, and all the air escaped from the side nearest the air inlets

True, but how narrow depends on the internal dynamics. With a bunch of holes having the cross sectional area of the tube somewhat more than the total cross sectional area of the holes should stop the last holes being starved but with a slot it is more dynamic. At low flow there will be total starvation but at high flow the early part of the slot may even suck air in.

The only way to be sure it to try it so at the first opportunity I will be blowing smoke through my ring

Mike

I never thought that for the sake of 3d printing, I would go vape.
Ape, yes, vape, no.

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leadinglights
The only way to be sure it to try it so at the first opportunity I will be blowing smoke through my ring

That gave me laugh

I have not been able to get a good photo, but I from what I have seen it looks like it does give a supply all the way around the ring, at least on the limits of the pump I tried it with.
Photo below shows the setup to do the smoke test. Air from the aquarium pump is blown through a stainless steel tube which is heated with a propane torch and fed to the air ring.


With this and the pump at max flow, 7.2 liters per minute, there was no smoke until the wood chips ignited. For several seconds there was a great deal of smoke which was clearly from all around the ring. Unfortunately this experiment was curtailed when the burning wood started coming out of the air ring despite a bit of gauze intended to stop this. An earlier test used a 4mm bore brass tube instead of the 8mm stainless steel. In this test there was smoke from most of the ring but the flow was quite restricted by the wood chips blocking the brass tube but this smoke was not visible in any photo.
As it is too cold in the workshop to do much more and it is too expensive to heat unless I spend the whole day there, that simple test will have to do for now.

Mike

As promised, photos are here:

Quote
leadinglights
Air from the aquarium pump is blown through a stainless steel tube which is heated with a propane torch and fed to the air ring.

Great test! I'm surprised but happy to be shown to be wrong

Quote

Unfortunately this experiment was curtailed when the burning wood started coming out of the air ring
...
As it is too cold in the workshop to do much more...

I think you nearly found the fix for a cold workshop!

Edit: it occurs to me that I have a Halloween fog machine in the basement, I wonder if the fluid from that could be used as a smoke source for the sort of test you described. If I can introduce drops from a syringe onto a hot surface I think that would probably do the job. The fluid is available quite cheaply, e.g.

[www.amazon.ca]

Edited 1 time(s). Last edit at 02/09/2017 11:11AM by JamesK.

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Lykle
As promised, photos are here:

Those are incredibly good bridges but I don't see the Berd Air ring in the picture.

Mike

Drat, I think I'm going to have to search the forum for tips on bridging. I can't print that part very well at all.

How about using a vacuum cleaner?
suck air by?
lots of suck air volume from vacuum?

long hose with noisy part in sound proof room

whole house Vac would be nice?

I wonder if vac could run for 8 hour print
perhaps water or cryo cooling?

Yeah sorry Mike, I will ask Brian for some photo's of the cooling rings underneath.
All I have is a photo of the effector with the Nimbles and air hose going down into the effector.
I will get a pic from below.

Lykle

As promised.

That is an amazingly small pipe but must be adequate from the bridges.

If I understand his posting, cozmicray is suggesting using a vacuum. I think that this may be an idea worth trying although the geometry of air flowing out of a nozzle is not the same as air going into a hole, Brian's results would seem to indicate that success needs not much more than a gentle breeze - not a whole house vacuum, sorry cozmicray.

Mike

His pipe is 2.5 or 2.3 or so. I am going to be using 2.9 when I get round to it.
The pump is pretty big, but still quite quiet. (Hard to write when you are dyslexic)
And he has it down to 25% PWM or so.

So yes, it does look as if you only need a little bit of air.

Lykle

What pump ist it precisely? I am in the procces of making something similar, but probably with a 4mm tube. I have bought a 300l/h or 5l/min aquarium pump, which I hope to be able to modify to run off a 24V DC, since I want it to be controlled by the printer, instead of just running continuously...

I have this one.
[www.aliexpress.com]

I am checking to see what Brian used. Will get back to you.

Lykle

OK, that was quick. As promised.

Here is the one used in the photos.
[www.aliexpress.com]

Only difference is that you can order it 12V or 24V, the rest of the specs are the same as mine.

Lykle

Quote
leadinglights
That is an amazingly small pipe but must be adequate from the bridges.

If I understand his posting, cozmicray is suggesting using a vacuum. I think that this may be an idea worth trying although the geometry of air flowing out of a nozzle is not the same as air going into a hole, Brian's results would seem to indicate that success needs not much more than a gentle breeze - not a whole house vacuum, sorry cozmicray.

Mike

It's the same diameter pipe used when you buy the berdair tube..

I do need to add socks to my chimera though as the air does end up coming out warm being so close to the heat block.

I think a vacuum would result in warm air as well, at least when heating the bed.

Edited 2 time(s). Last edit at 02/21/2017 07:42PM by briangilbert.

What would be the best approach to connecting a pair of 12v air pumps to a 24v printer? Would it be better to use a 12v power supply like this? Thanks....

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simspeed
What would be the best approach to connecting a pair of 12v air pumps to a 24v printer? Would it be better to use a 12v power supply like this? Thanks....

I'd suggest voltage regulators for each probably, not sure how well you'll go PWM'ing 2 12v pumps on a 24v supply tho if thats what you want.

The pumps don't appear to draw much amperage so they may work on the main power supply considering that my heat bed is mains powered. I guess I could run two SSR controllers and use the small power supply packs instead. I'm actually planning to run 3 pumps; one for the part cooling, one for the hot end heat break, and the last for the XY steppers that are mounted inside the heated enclosure.

use your compressor

[woodworker.com]

Quote
simspeed
The pumps don't appear to draw much amperage so they may work on the main power supply considering that my heat bed is mains powered. I guess I could run two SSR controllers and use the small power supply packs instead. I'm actually planning to run 3 pumps; one for the part cooling, one for the hot end heat break, and the last for the XY steppers that are mounted inside the heated enclosure.

I have mine running straight off the fan PWM output on my Duet, no issues to date.