Beginner Blower Idea

[Chelonian]

I'm still very much a  beginner to blacksmithing, but when I first started, I, like many others, needed a forge blower. I came up with this thing:

I know, it's pretty ridiculous, but it puts out almost (not quite, but surprisingly close) as much air as the Champion 400 blower I recently got. It's two junky kid bicycles that I got on the side of the road for free that I jumbled together. Since it is geared up twice, you really don't need to turn the crank very fast to produce air. It also coasts quite well because it uses the ratchet form the bike. Here's some kind of step-by-step instructions on how to build it:

Make three plywood circles, one slightly smaller than the other two. Make sure the smaller one will fit in the bike frame as a replacement for the rear wheel.

Make eight (I have no idea if eight is optimal, but it’s what I used) plywood rectangles and attach them to the smaller plywood circle as you would cut a pizza (this will be the fan blade).

Remove the rear wheel of the first bike by cutting all of the spokes (keep the hub, that's needed).

Drill a hole in the middle of the small plywood circle just large enough for the cone-shaped bit of the hub to fit through, but not the

part with the holes (that were originally for the spokes).

Drill small holes in the blade disk that line up with the spoke holes in the hub.

Attach the fan to the hub using small bolts and nuts. (Put threadlocker them, mine kept loosening up until I did)

Reinstall the hub/fan assembly back onto the bike and reattach the chain. (you should have the bike upside-down on its handlebars and seat from now on)

Now disassemble the other bike, and retrieve the small gear that is attached to the rear wheel, as well as the pedal assembly with the bearings and large gear. You will also need the chain.

Back to the main bike, cut off both pedal arms down fairly close to the base (I only have a hacksaw, so it took some time, but it is possible).

Now take the small gear from the second bike, and attach it onto the jam nut holding the bearing cone in place. On my bike parts, the diameter of the hole on the inside was very close in size to the jam nut, and I was able to grind a hexagon shape into the inside on the gear with a Dremel. This made them fit together very well, and the way in rotates should tighten the jam nut, not loosen it.

I then used some JB-Weld to attach it more permanently in place. (actually welding it would probably be better, but I don’t have a welder)

If all goes well, the gear should look something like this:

 

 

To attach the pedal bearing assembly to the bike frame, I just smashed the tube flat that I left on from the second bike’s frame, and bolted it onto the main bike's frame.

 

Cut one of the pedals arms off the second pedal assembly, but leave the other, as it will be your handle.

Take the chain from the second bike, and adjust it to size to get it to fit well onto the gears.

Now take the two large plywood disks and drill holes in the middle large enough to fit onto the rear wheel hub axle, and with a nut that threads onto the shaft, bolt them in place.

After making sure they fit well, take the one that is facing the blades off and cut air intake holes in it as close to the middle of the piece as possible.

I built the shroud to direct the air out of foamboard and cracker boxes, but it would be quite a bit nicer if it was made out of thin sheet metal.

Slowly funnel the outlet down until it is the size of the inlet on your forge.

You can also hack off unnecessary parts from the bike to make it lighter and easier to carry around.

I replaced the seat with the handlebars from the other bike to make the contraption more stable, but it isn't strictly necessary.

And you're done! I wish I had taken photos while I was building it, but I wasn't very optimistic about it actually working. Obviously, not all bikes will be the same, so you may have to improvise a bit to get it to work.

Have fun if you decide to build it!

 

[the iron dwarf]

thank you for posting this

I agree it may not look good but it is more important that it works

[Chelonian]

You're welcome!

I think you could make it look a lot better if you ground the paint off the bike frame, used metal as a shroud instead of foamboard and cracker boxes, and maybe painted the plywood.

[JHCC]

Cool idea. Maybe the next version can use the gears and derailleurs from a ten-speed.

[anvil]

takes up a lot of space.

[JHCC]

True, but a later version could be oriented vertically and/or have the elements overlapping rather than stretched out horizontally.

[ThomasPowers]

A box bellows would probably be simpler to build and use.

[Frosty]

Nothing wrong with making a blower out of an old bicycle or two. Somewhere I have pics of a street of blacksmiths in Asia I think. The pics show a narrow street packed shoulder to shoulder with blacksmith shops and the most common air source are blowers made from bicycles. A link in the menu on the right of my screen led to pics of the shop on another street that made and sold bicycle blowers, exhaust fans, room fans, grinding wheels, electric generators, etc.

I believe the link was posted here but it's been a while and I can't find it on my machine.

Sure, there are simpler ways to supply air to your fire but when it comes down to it it doesn't really make a lot of difference so long as there's enough volume at the right speed/psi.

Frosty The Lucky.