Could I turn a hand cranked blower into a electric blower?

[redbate]

I was thinking I can buy a hand cranked blower for not too much and can come across a relatively cheap motor to turn the crank for me so the coke fire won't go out? Has anyone done this? Would this be too fast? What would be a good motor RPM for this? I have a bunch of stepper motors lying around.

 

[Lieblad]

Sure. A stepper could do it, Obviously have to be strong enough, but less geekery would use an ordinary motor with appropriate gear reduction.

Dont discount an electric blower in concert with your hand cranker.
Simple flapper gate can be fashioned to automatically direct the electric air when the cranker is idle.

 

[stickwhistler]

I have an Alcosa (British made) with F30 on the gear box, and F43 on the impeller housing .
It has two spindles on the back, the left one is what I use for hand crank
and is a ratio of 1:40 ie 1 turn of the handle gives 40 revolutions of the impeller.

The other spindle has a sprocket - similar to a bicycle wheel sprocket - and was
operated ( by the former owner who I bought it off ) by a chain from a tractor power-take-off,
with the tractor engine at idle ie tick over. The ratio for this is very much lower at 1:8.

So it is possible, although I have to say it was scary watching this contraption running.
Much less frightening at hand crank speeds, which are easy a t approx' 50 revs per minute by hand
on the 1:40 spindle - easily gets to welding temp for forge welding.

Also, consider how long you will be forging the work ie 20 blows of the hammer (presumably by hand)
against the time in the fire - a couple of minutes, so that the fire will only have a short time
without being fed by the blower.

Recently I made a cutlass from 20mm round bar stock, and it took seven hours to get to
where I wanted to go to the grinder (usually I only work two hours at the forge at a time).
The blade was forged to 1.5 inches wide and 3/8 inch thick and was 8 inches longer than the
starting length.

Note to self: Make treadle hammer!