Scratchbuilt Smoke System?

[EightyMac]

Hey everybody. I am designing my own scratchbuilt fan-driven smoke system for HO steam and diesel locomotives. A drawing of my unit is attached to this post. Before I go any further, yes, I do realize that smoke is not a very popular feature in HO (and smoke-equipped HO diesels are even rarer). I respect other modellers' wishes, but we are entitled to our own opinions, right?

How this works is that a kerosene lantern wick is dipped into a brass cup filled with smoke fluid. The fluid saturates the wick from top to bottom. The upper end of the wick is placed on a metal rod wrapped in nichrome wire (the kind used in toaster heating elements), which heats the oil-saturated wick to produce smoke. The fan expells the smoke out the stack.

On steam engines, this is intended to be synchronized to a wheel- or axle-mounted cam (the same used for exhaust chuffs on Soundtraxx decoders) for a prototypical puffing effect. On diesels, this would be synchronized to simulate prime mover RPM changes (ie "Engine exhaust flicker" lighting function).

I also designed it to be very tiny--small enough to fit into the smokebox of an HO 0-6-0, and slim enough to fit under the hood of a Geep or diesel switcher.

 

[Charles Smiley]

Wow!

Make sure you run that by UL!

 

[frog]

Make sure you test that well before installing, check current draw and heat produced. A rather clever design. Why tissue for insulation?

The only loco I have that smokes is a Mike. I put a resistor in line with the motor as it would only smoke when the loco was at full speed. It looks okay, not too real, but I enjoy watching it.

Good luck with your project, hope you don't need a HO scale fire department.

 

[EightyMac]

Make sure you test that well before installing, check current draw and heat produced. A rather clever design. Why tissue for insulation?

I thought of tissue for insulation because paper (in general) is a poor conductor of heat and cold. I would have also used household insulation, but since the HO smoke unit is the size of a penny, I am not sure any store would sell such small quantities of insulation.

One more question about the unit-should I go for a flat wick or a round one?