Fan comparison with PLA.

Edited 2 time(s). Last edit at 06/19/2013 01:35AM by rsilvers.

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I'm not familiar with those fan sizes, 60x25mm and 8x25mm.

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[www.matter-replicator.com]

So more airflow = better models but how far can you go untill it starts making it worse again?

Well, I would like a 120mm fan except my printer is so small it is ridiculous. I think the answer is an 80mm with an air duct to focus the air.

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You can only constrict the duct on an axial fan about 10% before the fan stalls from the back-pressure. For this reason I prefer centrifugal blowers.

I also see that a duct will make interference more likely. I am going to skip the duct and change the angle by five degrees.

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I would like to do a Bowden blower, but it seems like all of the 12v blowers are really low CFM - like 17. I would like 50-100 CFM.

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I use 80CFM fans that are 80mm by 38mm thick for cooling my bed at the end of a build. They are very noisy and cost about £10.

Air is actually surprisingly viscous. It needs a lot of power to push it down a small tube. I don't really understand the comment about stalling. I constrict 80mm down to about 25mm with a funnel when I use them for fume extraction. Yes the airflow is much reduced because it takes power to push air down a 25mm tube a few metres long but it doesn't stall.

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[www.hydraraptor.blogspot.com]

So how do you do a duct cooler on a delta printer? i got a nice 30CFM centrifugel fan that is silent.

Made a duct - we will see if it improves the pyramid:

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The print got worse with the duct, so I removed it.

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I know from my model RC ducted fan days that the duct diameter is dependant on the fan swept area. Fan swept area is the diameter of the fan blade minus the fixed stator or fan nose. For higher air speed out the duct you can go down to 85% FSA but it will load your fan motor more and i doubt these little tiny fans can overcome much air packing inside the duct. The most efficient you can get is around 100% FSA, exhaust air speed will be a little slower. And if you really want to get efficiency you need a rounded lip on your inlet side as well.

To cool a print i would think you would want air moving all around not just pointed at a specific point.

You should try a duct more like this one which blows air from all around just below the nozzle.

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