Tips and Tricks for sail plane setup
Posted: Wed May 23, 2012 9:04 pm
I found these tips a while ago and I'm extracting the, for me, most important infos about how to setup a sailplane.
I'm sure, there are a lot of different ways to setup a model, but here are some basic tips.
These are the controls we are after: Aileron, elevator, rudder, brake (butterfly) and flaps (camber).
Aileron:
We wish aileron on all wing surfaces. To fly only thermal one can only use the outer surfaces (ailerons). As soon as we are on F3F/F3B we want half the amount aileron deflection on the inner surfaces (flaps).
Differential:
To make a model to turn better, we need differential. This mix makes the ailerons and flaps go less down than up. A simple guidance for thermal flying: 1/3 - 1/2 down versus 1 up. Speed and acro: 1/2 or equal down versus up.
Elevator:
As a main rule, you want equal amount up elevator as down. The more aft CG (Center of gravity), the less elevator throw. If the model gets very sensitive, have less down elevator or use exponential. Normal exponential is 20 - 40%.
Kick-Flap:
is a mix, that allows all surfaces to move togehter with the elevator. All surfaces down = more camber/lift and thereby same as elevator up throw. And of course opposite. On a new model I would always start without this mix.
Rudder for T- or X-Tail:
Equal to each side but not more than that it actually works. Too much and the rudder will slow you down or make it tip-stall.
Rudder for V-Tail:
Equal up/down but may be model dependant. If the model sets its nose down much, you can reduce the down slightly.
Combi-Switch:
It will give you automatical rudder movement when you use your ailerons . This is fine coming into a turn but will have the opposite effect coming out of the turn. So turn this mix OFF.
Brake or Butterfly or Crow:
The butterfly function should be on your throttle stick. Forward full speed and back for brake. With full brake the following should happen:
Ailerons slightly up (5-10mm), flaps as far down as possible and elevator slightly down as compensation for the increased lift of the wing. Compensation on butterfly should be dialed in at both half and full brake. The model should put nose slightly down to maintain airspeed. Often a model will need more compensation on half break than full. If not possible to set two settings then reduce the flap to 60 - 70 degrees. Mostly this is sufficient to give enough brake anyhow.
Camber means changing of airfoils lift.
Start camber:
When we start with winch/runners one needs to have a bigger camber / more lift on the wing than the model is produced with. Dependant of model type, condition and hook position you will need 10 - 30 degree launching camber. As a general rule you want equal camber on flaps and aileron surfaces.
Speed flaps:
When flying speed and distance we often want a faster airfoil. This is done by all surfaces on the wing going up 1 - 5 degrees.
Thermal flaps:
When flying duration and partly distance we want to change the airfoil so that it becomes more lifting (1-10 degrees). This is done by all surfaces on the wing going down. As a main rule you want more camber the better the air you are flying in. When you find the lift, you use as much as possible but not so much, that the model becomes "low tail" or critical to fly. Most pilots adjust thermal flaps by a switch or maybe two. Some like to adjust it on a lever.
Reinhard
I'm sure, there are a lot of different ways to setup a model, but here are some basic tips.
These are the controls we are after: Aileron, elevator, rudder, brake (butterfly) and flaps (camber).
Aileron:
We wish aileron on all wing surfaces. To fly only thermal one can only use the outer surfaces (ailerons). As soon as we are on F3F/F3B we want half the amount aileron deflection on the inner surfaces (flaps).
Differential:
To make a model to turn better, we need differential. This mix makes the ailerons and flaps go less down than up. A simple guidance for thermal flying: 1/3 - 1/2 down versus 1 up. Speed and acro: 1/2 or equal down versus up.
Elevator:
As a main rule, you want equal amount up elevator as down. The more aft CG (Center of gravity), the less elevator throw. If the model gets very sensitive, have less down elevator or use exponential. Normal exponential is 20 - 40%.
Kick-Flap:
is a mix, that allows all surfaces to move togehter with the elevator. All surfaces down = more camber/lift and thereby same as elevator up throw. And of course opposite. On a new model I would always start without this mix.
Rudder for T- or X-Tail:
Equal to each side but not more than that it actually works. Too much and the rudder will slow you down or make it tip-stall.
Rudder for V-Tail:
Equal up/down but may be model dependant. If the model sets its nose down much, you can reduce the down slightly.
Combi-Switch:
It will give you automatical rudder movement when you use your ailerons . This is fine coming into a turn but will have the opposite effect coming out of the turn. So turn this mix OFF.
Brake or Butterfly or Crow:
The butterfly function should be on your throttle stick. Forward full speed and back for brake. With full brake the following should happen:
Ailerons slightly up (5-10mm), flaps as far down as possible and elevator slightly down as compensation for the increased lift of the wing. Compensation on butterfly should be dialed in at both half and full brake. The model should put nose slightly down to maintain airspeed. Often a model will need more compensation on half break than full. If not possible to set two settings then reduce the flap to 60 - 70 degrees. Mostly this is sufficient to give enough brake anyhow.
Camber means changing of airfoils lift.
Start camber:
When we start with winch/runners one needs to have a bigger camber / more lift on the wing than the model is produced with. Dependant of model type, condition and hook position you will need 10 - 30 degree launching camber. As a general rule you want equal camber on flaps and aileron surfaces.
Speed flaps:
When flying speed and distance we often want a faster airfoil. This is done by all surfaces on the wing going up 1 - 5 degrees.
Thermal flaps:
When flying duration and partly distance we want to change the airfoil so that it becomes more lifting (1-10 degrees). This is done by all surfaces on the wing going down. As a main rule you want more camber the better the air you are flying in. When you find the lift, you use as much as possible but not so much, that the model becomes "low tail" or critical to fly. Most pilots adjust thermal flaps by a switch or maybe two. Some like to adjust it on a lever.
Reinhard
