I am in the process of completing my smoke machine. It is every bit a functional as the professional models. I made the body out of 2 pieces of 3 inch diameter abs sewer pipe, a coupling, cap and a clean out. I used utility box covers for the plates inside that the wick mounts too. I used 18 inches of heating wire from an old dryer element, I wound the wire into two coils (9" each) around a 3/4 inch bolt to form them. My prototype only had one wick but I was getting carbonization of the top part of the wick. I got two wicks from those outdoor torches 7/8 inch diameter by 8 inchs long. I used a propane regulator to control the pressure. I just grabed it off an old bbq at the dump. The requlate the pressure to aprox 11" water column, mine puts out about 13 in wc. If you want to have a adjustable pressure get a regulator off of a disposable propane cylinder. They are usually adjustable from 5" to 17". You want around 13" water column. I also used the orifice off of the scrap bbq and drilled it out to 3/32 of an inch to limit the flow of the smoke. I found if I had to much flow it picked up an oil mist and carried it with the smoke. I used a chunk of clear tube to make a u-tube manometer. It is a very accurate way to measure water column it also serves as a relief valve. If the regulator fails it will blow the water out of the u-tube and vent the system, saving the cars systems. A flow gauge can be obtained from omega.com for just under $100, I have not purchased one yet. If you do go with the flow gauge (rotometer) you can also purchase orifices to "calibrate it for the differents size leaks" very cheap from a pneumatic store. I will posts some pics on line in the next few days for anybody that wants to see what it looks like. The total cost without the flow gauge is under $40.
Almost forgot, my system is powered from a old computer powersupply at 5 volts and about 5 1/2 amps.
