I want to make a blower to use with my 2 bucket cyclone
'cause this shop vac is just too damn loud.
I want to use an induction motor
and I think the most suitable one from my collection
is probably this one.
This motor is a two third horsepower motor from a
really cheap table saw.
And what's cool is it has these flanges
that used to be for mounting a blade on here
and that will be very convenient for mounting the impeller.
And I have to figure out if this motor is powerful enough
so I'm gonna test this by just spinning a blade in free air.
The current was out of range of the power meter
so it definitely overloaded. I have to shorten those blades a little bit.
14 amps is still too much so I gotta shorten it some more.
Experimenting some more I cut a little bit of width off of here
and that allowed me to extend the length a little bit.
And with that I might be able to get away with a rotor thatch as large as
34 centimeters or about 13 1/2 inches.
I just spent a bunch of time designing the impeller
and the spiral housing
on the computer.
And I went with a 35 centimeter diameter impeller.
That's about 14 inches. Which is quite large
Normally that size impeller is for like 3 horsepower dust collectors.
So, with this motor its very iffy.
If it's a bit too large I can always cut a little bit off the edge.
But I figured with the backward curved blades
and keeping it relatively thin I should be ok with a two third horsepower motor.
And I also printed out
cutting templates for all the curved veins that go on the impeller.
Rather than glue a paper template on here
I just recreate that shape using compasses.
Dividing a circle by 6 is easy and then I
bisected those to get divided by 12.
And I marked the angles where these are supposed to start and end.
And I'm just checking that if I place these fins on the tick marks I made
that looks about right.
Hmm. Need more hand planes.
Oh, I think I can use those guys.
While that's drying I'll start working on the spiral housing.
This time around I'm building up the housing in layers of short pieces.
And once I've got these all sandwiched and glued together
I can cut them out on the band saw.
This glue-up is turning out to be not quite as
straight forward as I was hoping it would be.
Because the clamps keep getting in the way
putting the template on it.
So, almost going freehand.
I'm balancing the impeller on a marble
to see if it has the tendency to tip to one side or the other.
And it pretty consistently tips this way.
So I made this counterweight to glue in here.
And that makes it pretty much even, whichever way it goes.
So I think that mostly balances it.
Well, here's a major screw-up.
It turns out my motor runs this way.
And these veins need to be curved away from the rotation.
It needs to go this way otherwise it's way too inefficient.
So, I'll have to try and figure out how to reverse that motor.
And cursing a fair bit
I've come up with another solution which is to
cut out the middle of this propeller.
And then just flip it over
and make this the mounting side and
now I've got my veins curving the right way.
Have to be very careful to get this on
the right way
right away because if I slide it around too much I spread the glue.
And it's gotta be lined up perfectly.
Otherwise this things gonna be really off center.
It's much easier to work out where these segments go
if I clamp it in a way that I always have the template handy.
So no clamping from this side this time.
Got the motor put back together.
And the impeller mounted and it runs pretty round.
Although I did have to shim a little bit back here
to achieve that.
Only 9.9 amperes. I could have made it bigger.
37 centimeters of suction.
Not bad for a dust collector.
So based on my readings
this little one should be able to out-suck the big one.
So let's give it a try.
And it really does out-suck the big one.
It really sucks.