Handcrank/electric

[jayco]

I've also been using a small cooling fan from an old refrigerator.......about the same size.
It just hangs by a piece of coat hanger wire like the one in the picture.
I wanted to try different fans to see if results were the same. This seems to work with any small cooling fan.

Because of the housing design, the second fan didn't seal around the intake hole on the handcrank blower very well,........so I made a gasket from two old socks to stop the leaks. Very low tech!

The air output from these little fans is low,(think hairdryer or your car heater fan on low), but it keeps the fire at 'fast idle'.

I have worked on small stuff,something like leaf keyrings, for hours without ever touching the handle on the handcrank,

The most noticeable improvement for me was finding how much easier it was to build a fire in the mornings.

I found I could light my usual balled newspaper/woodshavings/small sticks kindling.........wait until the fire caught up a bit.....then plug in the electric fan.
I'm not anchored to the handcrank anymore......I can use both hands to shovel coal around the firepot,rake coal into the fire,get my stock ready, choose hammers and tongs for the next forging......maybe even sip some coffee while the fire is getting hot.

Even though the fans are small, small stock will in some cases burn if you're not watching closely enough.

If you're used to handcrank, like I was for so many years,you just have to remember that the fire burns on....even when you're not looking.

Of course that's what the electric blower guys have known all along.

[drogo]

As for a Switch system try using a reed switch (security switch for windows) the kind that uses a magnet to activate. Put the magnet on the handel to the blower and the switch on the blower housing. when you want it "on", leave the handel in the right position and the electric fan stays on. You could also put the magnet on a swivel so the electric fan isn't going on and off with every turn of the blower handel.

hope this is clear

[jayco]

I was putting this little forge and blower together (using one of those 4 in. computer fans as the air supply) and noticed a problem.
Very little air into the forge! There was so little air that I thought I'd put the fan in backward! Well, I hadn't done that.

First of all, this is a tiny forge....the vertical air pipe is a grease gun tube........the horizontal pipe is only 1 in. inside diameter.

These little fans work on my regular forge as 'helpers' pretty well.....of course my regular forge has 3 in. air supply pipe.

These little fans don't have enough power to be constricted to a small pipe....say.......1 in.!

Oh well, live and learn.........

James

[rmcpb]

For their size they move a surprising amount of air BUT they are volume fans not pressure fans so they will not push through a constricted area.

[NateDJ]

To determine the presser that one of these fans put out we (computer modding guys) stack sheets of paper on top of them to see how many they will blow off. This is by NO means a scientific measurement but it gives us a good idea of which fan moves the most air pressure wise. For volume hang a sheet of paper and see how far away it will still move the paper. For a fan that will do what you are wanting you will likely spend $50.00-$100.00 and are looking for a fan that is built to go in a rack mount server. These fans are VERY loud compared to other computer fans but also move a lot more air. A different approach that seems to work is to stack 2 of the same fans on top of each other, this will increase the presser but not the volume of air.
You can find a computer modding forum that has more info than you can ever care to read at bit-tech.net Forums
If you are interest in a very strange computer I made for my wife...ThinkTank

[Ian]

Just as a 'think on'......

You need a cheap controlable source of air under enough pressure to run a forge yes?

That means idealy something (fanwise) thats built to shift a lot of air through narrow ducting. If it has at least four speed settings all wired up even better yes?

Chances are your about six feet away from one just like that everyday.

Even better chance you can get hold of that one pretty cheap from an autowreckers.

Running it from a 12V battery makes it portable and mains power independant and quite possibly capable of hours of service. (you can take two batteries if you can take one)

For the workshop you could possibly run it from a cheap battery charger, cheap and cheerful.

Make sense to anyone?