I used a mechanical elevator trim using springs on my little single seat Super Cub for several years. Worked OK, but I wanted a backup elevator control. I have been using this very small electric trim actuator from
Welcome to Firgelli Technologies Inc. - Micro Linear Motion For about 2 years. Works great and I love it. I have no electrical system on my VW engine, so I use a 12 Volt, 5 Amp, model airplane starting gell cell battery from Tower Hobbies, ( cost about $17.) I keep it charged with a small solar cell from Harbor Freight to power my handheld radio and electric elevator trim. The Actuator that I use is,
L12-S
Stroke -- 30mm
Gearing--210/1
Power-- 45N
Weight-- 34 Grams
Drain-- 200 ma @ 12 Volt
Price -- $70.
DPDT switch-- $6.
1 Meter Extension Cable-- $3. To go from Actuator installed in elevator to rear of fuselage.
I just mounted the Actuator on the inspection cover in the elevator where I used to have a Giant Scale model airplane servo for my homemade autopilot that I used for a couple of years. Got tired of watching the Autopilot have all the fun and took it out. In a high drag airframe like this, it doesn't make any difference. Its so small and light, in the JMR Special that I am building, it will be inside the elevator.
Full up elevator trim gives me the 45 knot approach speed that I use in this low inertia airframe with an EW of 450 lbs. The full up elevator trim on take-off is just right for best angle of climb, so after liftoff I give it a little down trim for a slower rate of climb. Max ROC is 42 knots @ 1200-1300 fpm, so I usually climb at 50-55 knots.
The Actuator in the 210/1 ratio is perfect for speed when used to operate a trim tab. The company also make Actuators for about any use.
Dan
PS-- Picture of the airplane while running up to check for oil leaks after a oil change.
Welcome to Firgelli Technologies Inc. - Micro Linear Motion For about 2 years. Works great and I love it. I have no electrical system on my VW engine, so I use a 12 Volt, 5 Amp, model airplane starting gell cell battery from Tower Hobbies, ( cost about $17.) I keep it charged with a small solar cell from Harbor Freight to power my handheld radio and electric elevator trim. The Actuator that I use is,
L12-S
Stroke -- 30mm
Gearing--210/1
Power-- 45N
Weight-- 34 Grams
Drain-- 200 ma @ 12 Volt
Price -- $70.
DPDT switch-- $6.
1 Meter Extension Cable-- $3. To go from Actuator installed in elevator to rear of fuselage.
I just mounted the Actuator on the inspection cover in the elevator where I used to have a Giant Scale model airplane servo for my homemade autopilot that I used for a couple of years. Got tired of watching the Autopilot have all the fun and took it out. In a high drag airframe like this, it doesn't make any difference. Its so small and light, in the JMR Special that I am building, it will be inside the elevator.
Full up elevator trim gives me the 45 knot approach speed that I use in this low inertia airframe with an EW of 450 lbs. The full up elevator trim on take-off is just right for best angle of climb, so after liftoff I give it a little down trim for a slower rate of climb. Max ROC is 42 knots @ 1200-1300 fpm, so I usually climb at 50-55 knots.
The Actuator in the 210/1 ratio is perfect for speed when used to operate a trim tab. The company also make Actuators for about any use.
Dan
PS-- Picture of the airplane while running up to check for oil leaks after a oil change.