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12v oscillating fan
#11
I desolder the little.blue trim.pot.on my voltage buckers and install 22awg wires leading to a larger potentiometer for finger twisting speed ontrol.

The pwm.motor.speed.controllers work.well too,but they should be 21khz or higher frequency, otherwise they will likely cause the fan motor to whine at reduced speeds. A couple.of.pwm led dimmers i have ae 13khz and slow.fans nicely, but they whine badly.

Mostcheap oscillatting fan motors are brushed motors. Not as effieient as brushless.

One could ger a silverstone ap182 and stick it on a gooseneck like musicians use for microphones. The ap182 has a built.in speed.controller and is quite.powerful on high and whisper quiet.on low with a 0.05 amp draw. High is 1.3 amps.

Fm181 has speed.control and slightly less.powerful but 0.27 amps.on high and.0.09 on low.

I never liked oscillating fans due to the additional cycling noise of the oscillator mechanics. Got a wally world.one in storage somewhere.
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#12
I have this PWM motor speed controller bookmarked.

https://www.amazon.com/KNACRO-controller...ay&sr=8-59

it is 25KHZ so it any reduced speed whine, should be silent to human ears, but perhaps Fido or Tiger would get irritated.

Its 20 amp rating is obviously excessive for an endless breeze fan, whose maximum amperage draw I do not know, but it comes with a ciggy plug so it cant be much more than 5 or 6 or it would get horrible reviews for premature failure.

This 40 amp model actually can turn the load on and the PWM controller completely OFF via the potentiometer. The first link will slow the fan motor until it stops but the controller itself will still have a small parasitic draw.

https://www.amazon.com/KNACRO-controller...ay&sr=8-60

I do not have experience with the two above products. I do have experience with lower rated versions of some other branding that are no longer available, I think they were 15 amps and 21khz, but I kept shooting myself in thge foot and reversing the input polarity and hearing a loud POP when hooking them up to the battery. Dumbassery at its finest.

the 20 amp model at least has a fuse built in which might have simply blown and prevented the POP!

My 92mm 7500 rpm Delta fans I use a 5 amp voltage bucker for speed control:

https://www.amazon.com/Adjustable-Conver...6A1CE498XY

Mine came with a small finned heatsink to attach to the one processor chip. I bought such chips for the 3 amp LM2596 chips for the 3 amp buckers i used in the past. My newest 92mm fan exceeds 3 amps on startup and i saw the 5 amp buckers were available so I was all over the more powerful fan.

That little rectangular blue thing is a potentiometer. i removed it, soldered wires to the holes where it resided, an used one of these 10 turn potentiometers to control the voltage and thus fan speed. These specific fans still require a very light tough with the 10 turn potentiometer to dial in very slow and quiet fan speeds.

https://www.amazon.com/3590S-2-103L-BOUR...entiometer

Those wanting more of a plug and play fan: https://www.surpluscenter.com/Brands/Hup...16-986.axd

https://www.surpluscenter.com/Electrical...6-1503.axd
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#13
I had posted about little 4” wallywold 12v usb fans, single speed fixed for $5.99. This was last month. Ive seen them for the same price since.
They say when you get older two things happen, one is you lose your memory and the other, I forget.

We have enough youth. How about a fountain of smart?
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#14
thinking a 8"-12" metal blade fan and i can adjust the blade angle,add a speed control and try to get a ceiling fan effect,larger blade moving slower,the smaller fans you have to get a higher rpm for them to move air,they whine and have that fast air sound
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#15
Fan blades need to be balanced and deviation in the blade pitch from one blade to another will cause cavitation on some of the blades if the pitch isn't spot on. Squirrel cage fans can be quiet at lower speeds.
Brian

2000 Roadtrek 200 Versatile "The Beast" (it has been tamed hopefully)  I feed it and it doesn't bite me.   Angel
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#16
Metal bladed fans have no thickness flow from leading to trailing edge. Its.just bent flat metal. That relies solely on the angle.of.attack to.capture air and force.it.forward. This thickness flow.across.each blade, this airfoil easily apparent on computer fan impellers, greatly increases the efficiency and reduces the noise each blade makes as it rotates.

Somebody could.make.an airplane fly with a purely flat wing, angled upwards. But it would take.huge amounts of.power to get it airborne. And could never approach the speed of.a wing with a nice lifting foil.

Look.into lhat 10$ ~6 inch 24 v e papst fan i linked elsewhere and the buck hoost converter for a.speed.control. this fan at.28 volts.is.extremely.powerful and quiet.considering that airflow. It draws 2.06 amps from a.12.6v battery through the buckboost converter use a.microphone gooseneck.to.adjust its.aim..some.sort.of.bracket.will have to be used to.attach it.to.the fan. The fan will spin down to.7.46 volts and draw 0.09.amps. taking it.over 28 volts.greatly increases amp.draw without much extra rpm or airflow achieved.

Really, bending the blades.of.a.metal bladed fan is in an attempt.to change its airflow is...unwise. the precision required to keep.it.from.vibrating is far beyond what the average joe could ever accomplish even attempting ultimate precision.with tools.that might allow.some. semblance of.accuracy to be achieved.
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#17
Every cheap 12v oscillating fan I have ever used in RVs or in trucking over a few decades was noisy and didn't last very long. This includes the ones you typically see on amazon or ebay with the spring loaded clamp...they are often available at truck stops, auto parts stores, and walmart.

The hobby motor, the plastic gears, and the mechanical oscillating parts are cheap, they wear out or fail not long after you start using them. The 'speed control' is often a simple resistor, and the clamp and arm get wobbly or loose after awhile. I don't know of a 'not cheap' one. If there is actually a good one you can buy for RVs, I have not seen it.

If you really want a decent oscillating fan, then a small 12v to 120v inverter and a household desktop oscillating fan might be an option.
Wondering about Wandering.
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  • TWIH (08-18-2019)
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