Hi all,

I am in the process of making a hand crank blower for my wood/charcoal forge which is approximately 600mm diameter and 300mm high.

i have worked out a gear train setup that would give a ratio of about 1:20 using old bike parts. I have seen 2 blower wheels on Ebay, a 88mm for $8 or a 180mm for $30.

As i am trying to do this as cheaply as possible, the 88mm seems pretty good for price. Roughly how well would the smaller wheel work if i could get it to 1000-2000 rpm?

Ebay link removed

 

 

Have you asked around if any local A/C guys or plumbers had an old blower sittin around? Either one might have somethin like the first one. Or you could build one yourself using scrap sheet metal. Have you ever seen the inside of a hank crank blower? The blades are nothin fancy and would be easy to replicate somethin just like them.

Is there a reason you don't just use a bathroom exhaust fan or somethin similar? I've had an exhaust fan hooked to mine every since I started and it works wonders and far much easier than tryin to build somethin from scratch and hope it works.

Edited August 8, 201510 yr by M Cochran

 

Have you asked around if any local A/C guys or plumbers had an old blower sittin around? Either one might have somethin like the first one. Or you could build one yourself using scrap sheet metal. Have you ever seen the inside of a hank crank blower? The blades are nothin fancy and would be easy to replicate somethin just like them.

Is there a reason you don't just use a bathroom exhaust fan or somethin similar? I've had an exhaust fan hooked to mine every since I started and it works wonders and far much easier than tryin to build somethin from scratch and hope it works.

thanks for the reply, building the blower wheel itself seems pretty simple.

i forgot to mention that im trying to go for a no-electricity approach.

As you are the builder you also set the specifications for the build. Reverse engineer the commercial  squirrel cage blowers as to diameter, rpm, and air output. This will give you a start on the diameter of the squirrel cage fan you need,  the rpm you will want to achieve, or the air volume output.

I started with an electric blower and later decided I liked the hand crank better years later I build a two lung blacksmith bellow and decided I liked it better than the hand crank, used it for a couple of decades till it started falling apart and passed it on to a friend when I moved 1500 miles.  If I was starting out with no electricity I would build a chinese box bellows, simple works well and doesn't take up the back of the ute to move it around.

I have been wanting to do one similar just for fun. I was looking to use the small diameter wheel off of a kids bike as the fan by placing blades across the spokes. To get some inertia built up I was thinking the tire could be filled to make it a flywheel of sorts. 

There are lots of inexpensive ways to move air for a forge without electricity. The box bellows are a simple, and effective way to do it. 

Edited August 9, 201510 yr by BIGGUNDOCTOR

Here's how we set one up in Congo.