LET’S TALK GIANT SCALE: SMOKE SYSTEMS
in the front of the model, you’ll find that your model is nose-heavy at the start of the flight. As the flight progresses, you’ll have to change the elevator trim as the model becomes more and more tail-heavy.
I prefer to run three lines out of my smoke tank. One line simply vents to the outside of the aircraft on the bottom of the model, the second attaches to the smoke pump (the internal line is attached to the clunk), and a third line used for filling the tank is attached to a fuel dot. I prefer to mount the pump close to the smoke tank and close to the tank’s height within the airframe. I also make the smoke battery removable. I use a 2000mAh NiMH pack, but with such a small current draw, a 500mAh battery could be used and will provide about 30 minutes of smoke-on time.
With TME and Sullivan smoke pumps, you’ll notice that two servo leads come out of the pump. One is connected to the battery and the second lead plugs into a spare channel port in the receiver to turn the system on and off.
If you feel that simply assigning your smoke pump to operate on a switch at one standard speed is acceptable, think again! When smoke is injected into the model’s muffler or exhaust system, it’s critical to change the volume of fluid being pumped. If too much oil is injected into the muffler while the throttle is at a low setting, it can kill the engine—not good for certain maneuvers, such as spins, with smoke on.
For my airplanes, I plug the smoke pump into a spare channel and assign it to a switch. For example, if I have
Aux 4 as a free port on my receiver, I’ll assign Aux 4 to the Mix Switch on my transmitter. Then, I will use one of the programmable mixes to mix Throttle (the master channel) to Aux 4 (the slave channel). I then assign this mix to the switch (Gear Switch) and program different points on my mix graph (using a mix curve) for different pump speeds to operate at in relation to the throttle setting. For example, at idle, I want the pump to barely operate so that little or no smoke fluid is pumped into the exhaust. As I increase the throttle, the smoke pump increases the flow. Using
both the Adjustable Travel Volume screen and the Mix function can change the rate at which the pump operates at its fullest potential. Remember, though, the curve mix is critical!
When programming the smoke volume, you can make most adjustments on the ground. For maximum power, though, let your engine idle for a minute or two on the ground. Then, activate your smoke
pump at or close to full power. If you see a large burst of smoke initially followed by a smaller amount of smoke, decrease your smoke rate: too much oil is being used. Making fine adjustments like this will ensure that you have a reliable and impressive amount of smoke during your flights. Fine-tuning the pump will also maximize your smoke-on time.