So last week I posted pics of a Mankel forge and anvil that I found on CL. I used it a little and found that I didn't like having the forge burning full blast while I was hammering a the anvil.
On my home made atmospheric brick forge I made an idle circuit from some brass fittins an electric solenoid and a switch. Its a simple setup and it saves gas.
So I started thinking (I know a very dangerous thing to do) that I need something similar for my "new" forge. It started out simple just a solenoid and idle valve, which I made, and then found that when I turned the gas low the blower motor was still going full force and would blow out the flame. And turning the gas low, reaching over to the blower door and closing it, then taking the hot metal out, then doing the reverse after the metal I was hammering cooled, seemed kinda awkward.
And so began the long electro-mechanical journey to make a control system that would lower gas usage and control the blower motor output.
Here's what I made;
And it actually works!!
I had most of the parts in stock, but ended up spending about $75 on items I didn't have.
Here's a closer view with labels :)
And here's whats inside :o simple right?
Here's a closer look inside.
The gas comes in, goes to a manifold that supplies the idle control vale, and the main gas control solenoid and valve, then exists thru the black hose to the forge.
On the bottom of the box is the 12 volt power supply for the blower motor, on the right side are two PWM's (pulse width modulator) that controls the high and low speed of the blower. And a DPST relay that switches between the two PWM's and controls the indicator lights. Oh and a fan to keep everything cool...and a molded hospital grade power cord!!!
When at idle the indicator light is on next to the idle control valve and the idle blower speed adjusting knob. When at full the light is on next to the full flow gas valve and the high speed blower adjustment knob. The lights get brighter or dimmer depending on the speed output.
I can now control the gas and blower from a safe distance from the forge. And have an almost infinite amount of gas output, and air input. I leave the blower door and gas valve on the forge wide open. And it all fits inside of a 8x8x4 pvc electrical box.