I use a quarter turn ball vavle with a on off switch, easy to reg. and cheap..

An air gate should be installed on the inlet side only. This way the motor is not loaded and the air does not get overpressurised. With an inlet side air gate, a rheostat is not needed.

A variable speed control for a router will handle the currant easily. Available at better wood working stores.....

you can get router controler at harborfreight for 20 bucks if theres one near you can go to there web site and order one

Myself I used a speed control in the past now I let the motor run and use a damper the avantage I have found when I forge weld I can use short blasts of air to bring the heat up fastwith out waiting for the motor to wind up. I had my eletronic control fail in the middle of a demo. thank goodness for a multy tool. rewired and back at it in 5 min.

Arftist has a point that I've considered many times. It's true that choking the outlet puts more load on the motor and choking the inlet reduces the load on the motor. The problem is that with a series wound motor (universal or brush-type motor) that the RPM is a function of load, so choking the inlet can cause the motor to run at excessive speed. While it is the most efficient solution, it might not be the best one. Then again, it probably doesn't hurt in most cases. The blowers that I sell through Kayne & Son use an inlet control. Either way has been used many times over and both seem to work.

One method that has not been mentioned is using the outlet valve as a "waste gate". You put a "Tee" in the line and use the valve to bleed off excess air. This works best if the valve is in a straight line off the blower and the air for the forge turns a 90. That way the "preferred" path for the air is to the valve. By this method the motor is neither over-loaded or over-sped. Point the outlet at the work area to cool off the smith!

Edited September 10, 200916 yr by nakedanvil

that would work good if you vented it up ypur side draft hood from the bottom would keep and up draft going I would think

as a side note a sewing machine motor would work good as a blower motor with a dimmer switch

On 9/4/2009 at 12:54 AM, Ragnarok said:

hey, I've got my eye on an electric forge blower, but the speed controller is missing, can anyone tell me where i can get a speed controller from or what the proper name for them is, and how much it's likely to cost...

Or is it better to just put a valve in the air way and have an on/off switch?

thanks all
Rune

What type of motor Your blower has? 

Motor speed controllers depend totally on the type of motor you have. A universal motor can be controlled by a simple rheostat  but that will burn up a different type of motor.

How much it will cost will depend on the type and on the size needed information you have not provided; so Free to several hundred US dollars.