November 16, 2006

JR 10X - TME "SUPER" - Electronic Flow Control

SMOKE OIL -This is a pdf of the source I use

There are a variety of oils out there.  Most commonly used, probably is "Aviation Products" "Super Dri", available from Tower Hobbies, Troy Built Models, and plenty of hobby shops.  It is pretty much the "gold standard" out there.

The ONLY drawback of Super Dri is the $50 per 5gal price.

The PF&F 700 that I use (pictured below) is available from a lubricants distributor locally for $37 per 5 gal pail, tax included.  That's not very much more than a lot of the "home brew" gooey solutions out here, so I went with it.

Home brew solutions vary a lot, but basically all use mineral lamp oil, kerosene, diesel, ATF, or various concoctions of a mix of those.  Many swear by using "concrete mold release agent", most popular there is Texaco "ALMAG", but it is thicker, and tends to be extremely touchy because of the viscosity issues.

REMEMBER the "RULE" of Great SMOKIN' SETUPS - Control FLOW rate properly and be CERTAIN there is NOT TOO MUCH and not too little flow.  Gassers produce all the heat you will EVER need to make great smoke.  The "trick" is getting the right FLOW into the muffler, at the right place, at the right TIME.

Varying FLOW based on throttle setting is absolutely essential, now that electronic flow control pumps are out there.  I use the TME Super Simple System III, many use the Sullivan "Smoke Writer", there are others.

To really have "airshow" quality smoke, you MUST vary flow based on throttle, and that means a good multi-point mix setup, in addition to having the overall "on/off" of the smoke pump SWITCHED at the Transmitter.

Don't overlook Rule One - Control Flow rate!!!!!!!!!!!!!!!  "Just right" is JUST RIGHT.

I copied my current "working" setup to another model memory. I plugged a good servo (long arm) into an extra RX I have in AUX 4, and measured how things were moving on the "working" setup. That's the one producing the CURRENT good results on my 30% Yak.

In my "experiment" setup, I then REMOVED the AUX4 > AUX4 mix I had been using to get the offset out of there. Set AUX 4 ATV (func 12) to +50 and -100.   This sets the overall "off" of the controller on the pump.

Then, I used a multi-point mix (mix 58 was my choice), and set it up with Mode "CURV", Expo "ON",  and on the "Switch" screen set the "GEAR" switch to control overall ON/OFF.

Went back and forth between the setups until the experimental setup SERVO movement matched (or is very close) to the "Working" setup. Then tried the experimental setup on the actual airplane, listening to the pump motor. Sounded like everything will be great.

Mix curve points are - Po - (Smoke OFF) - PL is OUT -100, P1 is OUT -100, PL is OUT -100 (these settings keep the servo/smoke pump OFF no matter where the throttle is located) - Gear Switch "OFF" (set to rear of TX)
..... For Smoke "ON" - p1 - PL is OUT -91, P1 is set point of 25, value OUT + 25, P2 is set point of 50, value OUT + 50, P3 is set point of 65, value OUT + 53, P4 is set point of 80, value OUT + 60, didn't use a P5 setting, PH (full throttle) is value OUT +76.

These values give a flow rate increase as the throttle stick moves. The "MAX FLOW" (max Smoke, FULL throttle) is actually set by changing the value of PH. Higher + will be more smoke fluid, lower, less. The "smoke ON" flow rate (and throttle point where it begins) is completely dependent on the P1 SET POINT, and P1 "Value". Again, higher value will be higher flow. You change the "throttle position" where it "comes on" by altering the P1 "SET POINT", left on the curve will be earlier in throttle, right will be later.

The P1 SET POINT and P1 VALUE is really what seems to be the "smoke ON" setting". But only with the GEAR switch "ON". Flip it back (off), servo goes to the "OFF" value. I verified all of this by watching and listening on the plane, and going back and forth between the two setups to be sure I wasn't screwin the pooch on this.