Thursday, December 26, 2013

Great Planes ElectriCub

First Cub was an ElectriCub in 1996, with original Mabuchi 550 type can motor and NiCd. Flew OK, but nothing outstanding.
Second was the 20-sized Great Planes Cub with OS FS 26. A lot of fun in the air, but often hand-launched because hard to control on the ground.
Now found another ElectriCub kit on EBay. Came with yellow MonoKote, though unfortunately plain yellow, not the special Cub Yellow. Built it in about 6 month.




Outstanding flyer with 3 cell LiPo, brushless motor. Added ailerons, approximately scale sized, but forgot to remove dihedral from original kit design, so very little effect.Mixing rudder to airleron for relaxed flying. Second image shows transmitter in 'winter bag' for cold weather flying.

Tuesday, November 26, 2013

Futaba 9C Throttle Lock

To get a "Throttle Lock" for electric motors on the Futaba 9C while not in a heli mode:

  • Select one of the programmable mixes
  • SW: E, Posi: Down
  • Mix: On
  • Mas: Thro, Slv: Thro
  • Link, Trim: Leave Off
  • Offset: 0% (Throttle stick to idle, then hold rotary for 1sec)
  • Rate 'down': +100%, 'up': -100%
Similarly for the T8FG:
  • Offset Y at -100
  • Rate -100 for both directions

Friday, August 2, 2013

Super Slinky



This was a free plan in the January 2013 R/C Model Aeroplane magazine, by Alex Whittaker, including
 "...ye olde health warning. Super Slinky is the Yorkie bar of simple sportsters. She's not for girls, the faint-hearted, Guardian readers, those of a nervous disposition or Southern jessies. She's no trainer, follow-on trainer or first low winger. She's for experienced pilots, aerobatic hooligans and unrepentant throttle benders. The truth is, she's a very bad girl."

With a warning like that, I couldn't resist. The original idea of the plan is a very quick build. One type of rib, box fuse, plank tail. Of course it took me 3 month, using stick-build tail, one extra wing bay, and in general every attempt to not rush it.

Wingspan110 cm
Length90 cm
Area27.5 dm2
Weight1275 g
Loading46.4 g/dm2
AirfoilSemi-Symmetrical
EngineOS 25

First flight was on 2013/08/01, thanks to Bill L. for providing the wing rubber bands! Very easy to fly, maybe as a result of slightly larger wing and CG abt. 2cm in front of main spar, since several internet posts warned about a CG that is too far back. Later used the "Brush Script Std." font as template for wing marking.

Monday, April 1, 2013

"Throttle Hold" for RC boat or car

The Futaba T8 has a "smart" throttle hold option, meaning: The throttle hold will only engage when the throttle stick is close to the low position. Makes sense for an airplane or helicopter that uses a range of idle-to-full throttle. Does not help with a car or boat where you want reverse/stop/forward.

For a boat I wanted the throttle hold to hold the throttle output at 50%, but the built-in throttle hold function would only engage after moving the throttle stick near the full reverse position.

Fix: Use throttle curves.
Curve 1: usual 0..100% linear curve.
Curve 2: Always at 50%, with switch "SF" to engage, the same one I otherwise use for throttle hold.