Have just made a prototype of a fan forced smoker which seems to be working well (despite breaking the heater coil by moving it while hot, - had it apart, broke wire, screw and washer repair, not quite as hot) I bought a couple of Heng Long smokers (for R/C tanks or cars) to play with, for $10 NZ each(or 5.3 Euros to you Northerners give or take a yen) from Bangood and just bought another from Ebay. There seem to be 2 different models, as one has a long coil with a lamp wick draped over it, which is sitting in the oil reservoir, the other has a small coil inside a piece of heat resistant woven tubing (as you might find insulating toaster/heater wiring etc) which acts as a wick and that also sits in cotton wool in the reservoir, (this seems to be the better of the two) Tip - don't fill the tank right up, only enough to soak the cotton, element should be just out of the oil. The wick loads the element.
The better model seems to have a black top to the tank (also maybe either brown or black tank) and the other has a brown top and dirty brown tank. As with most of this stuff you won't know till you get it what it's going to be.
What I did was remove the tank and cut off the pump tube just in front of the screw lugs (see black line in photo) then fitted the tank, and a 40x40x10 5v ESC fan (voltage controlled by a UBEC set to 5v on the jumpers) into a plastic electronics utility box from Jaycar (our local electronics and hobby store). I made up a double JST lead for the 2s 1800Mah Lipo and fired it up (using baby oil). it's pretty much silent and smokes well once it gets warmed up, ( starts smoking in about 5 seconds)
You could control it (on/off volume) by either a remote on/off switch or perhaps a small cheap 10A brushed ESC. I would leave the fan running and control the element to avoid burning the element. The original pump tank inlet hole seems ok as is (approx 1.5mm) but you could enlarge it very slightly to get a better flow if you could find a better oil. At the electronics store they have proper smoke machine oil for $20 NZ per litre so I may have a look at that.
The reason I went for the fan idea was that I found in std pump form, if I immersed a tube from the tank in water, it sucked water back into the tank. I was hoping it would pump smoke out of my HSL exhausts at water level alongside the cooling water but it would need a very light non return valve to do this. The fan seems to pump the smoke through 2mm ID silicone tube ok, so tubing of similar ID to the OD of the tank
outlet
s should work well.
These pumps in original form work pretty well for the price, and are cheap enough to keep a few for spare elements, the only thing is they are a bit noisy but in an 'engine sounding' way, (might add to the effect on a tug or work-boat though) What you have left after this mod is a very handy little geared motor with an eccentric output wheel which could be used for winches, radar and whirly bits of any description (see pic of motor leftover and original) To avoid burnout, these should be run on no more than a 2s (around 7.5v-(suggest 8v max with fan running)
The other tank is going to work a lot better than this one but I'm not making a tug, just want a bit of exhaust smoke on start-up etc to go with the 2 sound units. Very cheap to make (around $25 NZ with pump, box, fan and UBEC all through Ebay, Aliexpress and Bangood (and local electronics store)
if you wanted to run an ESC to control the smoke and you have no channels left to control it proportionally, you can always try using a second receiver bound to your TX, (if your TX will allow it,) power it and a brushed ESC (wired to the element) as normal and use the throttle channel to plug in your smoke control. This should work if you want more smoke as you accelerate or if you are using only 1 stick on a 2 stick TX you could use your 'elevator' stick pushed up (or a toggle switch if available) to start/stop the smoke (through the brushed ESC setup) . This setup weighs 100g (10g more than std)
The quest for lots of smoke continues Will try to upload vid later and update progress.