Homemade Blower

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mopar head

mopar head

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Naa, not that kind of blower, a squirrel cage type.
I asked to have the housing and fan that was left laying on a construction site years ago, it looked new.
Also I won bid on some large, 18" flex collection hose, years ago, and decided to put the two together.
I`m going to media blast/paint, whatever in a temp. tent rigg inside my shop. hopefully it`ll do the job, we shall see.
A NewYorker roof donated some of its metal for the 8x18" transition.
1/2" shaft, a few bought bearings, 1-1/4 sq. tube, a little plate, and paint to make it what it ain`t.
It blows real strong, hope it draws just as well.View attachment sssss 025 (Small).jpg

View attachment sssss 021 (Small).jpgAnd of it installed, it`s just going to blow out the window, and make me real popular with my neighbors.
With mainload bearings outside of housing, it should make it wear, and explosion resistant:mrgreen:
 

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I do very little arc welding in shop, mostly Mig and Tig, which does`nt produce much smoke. Paint fumes would be the most bitchable offense.
I live on the edge of the developement and the wind usually blows out of neighborhood. I think I`ll be ok. I`ve been exhausting smoke/dust for 17 years without complaint. k.o.w.
 
They'll get over it. When I get a house I'll probably get a surplus blower and put a stack up so it goes over. I do a lot of welding though.
 
Good Idea too. I have a discontinued $$ woodstove flue I thought of piping through that, but it`s only 6", and decided against it.
I`ll update and say if it works good or not, it`ll be awhile.
I`ve been using 2 large attic fans in each window, creating a good crossflow, but with paintfumes, I`m worried that the motors may ignite them. I`ll feel safer with this blower setup.
 
A word of caution if you are going to use that to exhaust paint fumes. You might benefit from enclosing the motor in a sealed box, and running a vent tube through the wall away from the window. Paint fumes can explode violently. The brushes in that motor are all they need to ignite.
 
As in first post, blasting/painting will be done in a temporary tent, with a 18" hose exhausting to this blower. Inlet air will be from a filtered door.
Me try be no dummy:mrgreen:
 
Hey mopar head i'm guessing with that being one speed it can get pretty loud.Have you thought about putting a variable control on it i did something very similar with squirrel cage a while back and found that a variable router control box worked like a charm you just need to make sure it can handle your motors amps as i used a 1/3 hp motor i was just fine.This is for when you dont need full force just some ventilation.
 
Arco440 said:
Hey mopar head i'm guessing with that being one speed it can get pretty loud.Have you thought about putting a variable control on it i did something very similar with squirrel cage a while back and found that a variable router control box worked like a charm you just need to make sure it can handle your motors amps as i used a 1/3 hp motor i was just fine.This is for when you dont need full force just some ventilation.
Click to expand...
It does`nt seem to be much louder than the attic fans I had in the window.
Funny thing you mentioned amps, and this is what confuses me.
I reserched and asked our local electric motor repair guy about what speed these things could be safely run at and he said about 1000 rpm.
This motor was given to me by my Dad, it`s a 3/4 horse 1725 rpm and he decifered my driven pully size to slow down to this speed and mentioned me maybe haveing problems with it drawing too many amps?
Well low and behold, I turned it on to let it run a while and the motor shut down, damn, He said if it did have problems I would need to choke the outlet down to compensate. So I made an adjustable knife valve to do so and got it to run without the motor shutting down, But it sure seems to have cut down a bunch of draw from the inlet by doing so.
So I ask you or any other knowlageable electric motor people, where I should go from here to resolve this? smaller motor? I`d like to open the outlet back up, cause I`m thinking it will need it, to draw as powerful as I need it for my application:banghead:
 
With a capacitor motor like that you should not try to slow it down electrically - you will eventually let the smoke out of it.

All you need to do is slow the blower wheel down a little. It is overloading the motor.

Inclined squirrel cage blower like that have a fairly linear relationship between speed & horsepower requirements. The horsepower required is dependent on both inlet & outlet restrictions.

If you look at a commercial air handler, or a big swamp cooler you will see that there is an adjustable pulley on the motor shaft. This is used for fine tuning once the blower is in place. An amp meter is used on the motor circuit, and using the amp rating on the motor the pulley is adjusted so that the running blower draws slightly less than the full load amps on the motor nameplate.

You are close on speeds if the motor took more than 15 minutes to overheat. if it shut down in two minutes, you probably need a bigger pulley on the fan. If it was 15 minutes or longer, go down an inch on the motor pulley and see if that solves the issue. If you can borrow a clamp on amp meter, do the adjustment properly. The adjustable pulleys are not expensive, and anyplace with swamp cooler parts has them on the shelf. If it was still summer Home depot would have what you need. Most farm stores should too.

My garage has a 6500 cfm cooler installed. It sure is nice to pop the door open & crank that thing up when the air gets foul. Also nice to have a cool garage in the summer here.

Nice work on the fan. Get the speed right & it will serve you well.

B.
 
bohica2xo said:
With a capacitor motor like that you should not try to slow it down electrically - you will eventually let the smoke out of it.

All you need to do is slow the blower wheel down a little. It is overloading the motor.

Inclined squirrel cage blower like that have a fairly linear relationship between speed & horsepower requirements. The horsepower required is dependent on both inlet & outlet restrictions.

If you look at a commercial air handler, or a big swamp cooler you will see that there is an adjustable pulley on the motor shaft. This is used for fine tuning once the blower is in place. An amp meter is used on the motor circuit, and using the amp rating on the motor the pulley is adjusted so that the running blower draws slightly less than the full load amps on the motor nameplate.

You are close on speeds if the motor took more than 15 minutes to overheat. if it shut down in two minutes, you probably need a bigger pulley on the fan. If it was 15 minutes or longer, go down an inch on the motor pulley and see if that solves the issue. If you can borrow a clamp on amp meter, do the adjustment properly. The adjustable pulleys are not expensive, and anyplace with swamp cooler parts has them on the shelf. If it was still summer Home depot would have what you need. Most farm stores should too.

My garage has a 6500 cfm cooler installed. It sure is nice to pop the door open & crank that thing up when the air gets foul. Also nice to have a cool garage in the summer here.

Nice work on the fan. Get the speed right & it will serve you well.

B.
Click to expand...
Thanks bohica,
You explain it well, it took only about 2-3 min. for the motor to shut down.
I`m in it this far, I cant give up now. Sounds like the varible pully and the meter is the way to go. The motor does have a 2 step pully a 2" and 3",
The pully calculator was used with the 3" to determine a 5" to get roughly 1000 rpm, but it seems the amp draw is the big picture here. thanks again
 
2 minutes? Yep, you are trying to pull a trailer with a slant six, 2.73 rear gears & 31 inch tires - up a 6% grade without downshifting.

Go up a couple of inches on the fan pulley. Then you can tune for max with a meter & adjustable pulley.

That or upgrade to a 1.5 horsepower motor - sort of like a 413 swap.

B.
 
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