Compressed / Aquarium Air pump tubing

lael

So, just about to experiment with using an aquarium pump / berd air pump (will test both options) for a new install. I'm wondering if anyone has used larger diameter (6-8mm) silicone tube for the run to the print head and then split into two cooling jets?

I'm thinking something like 8mm ID, and 10mm OD (IE 1mm wall) to keep the weight down, but wasn't sure if that would collapse too easily, or if the pressure from the pump would keep it from kinking. Then split to 6mm ID for each tusk. 8mm Area is ~50mm^2 and 2x6mm is ~28mm^2x2 / 56. So there might be a small pressure drop into the 6mm tube, before considering the split and the actual air jet outlet size that will add pressure.

Or... is a 2mm wall thickness actually a much better idea?

cosmowave

@lael i think, if the hose collapse or not will more depend on the material as on the diameter!?

deckingman

@lael Can you print at 300mm/sec? The reason I ask is because I can and the moving mass of my 6 input hot end is 2.5Kgs. I'm limited to 300mm/sec because that is the maximum melt rate of my hot end, not because of the mass. So use thicker wall tubing and don't get hung up about the mass.

lael

@cosmowave Right, so that's why I'm debating between 1mm wall thickness vs 2mm wall thickness.

lael

@deckingman pretty impressive, but surely you are getting a whole lot of ringing if you are attempting to print those speeds with that mass?

o_lampe

@lael I have a lot of experience with aquarium air pumps and IMHO it's almost impossible to split the airstream equally without adding an adjuster valve.

deckingman

@lael said in Compressed / Aquarium Air pump tubing:

@deckingman pretty impressive, but surely you are getting a whole lot of ringing if you are attempting to print those speeds with that mass?

Nope - none at all. I have a theory that ringing is caused by resonance. If that is indeed the case, then increasing the mass will reduce the resonant frequency which is why I have never seen any sign on ringing, ghosting, or any other surface defects which seem to afflict a lot of people.

lael

@o_lampe Thanks, that makes some sense. I'll get some valves ordered.