For beginners - Computer Radios and Surface Mixes
10-06-2003 | 03:36 AM
#1
For beginners - Computer Radios and Surface Mixes
You will hear the terms v-tail mixing or elevon mixing. What is that?
And, you will get a debate on whether you need a standard radio or a computer radio and what mixes come with each. What does that mean?
Here is a short primer on surface mixes. I invite others to clarify or correct my comments and add where these mixes, or others, are used.
V-tail mixing and elevon mixing - These are becoming more common on standard radios, but used to require computer radios.
The term V-Tail mixing comes from the fact that on a V-tail plane, you do not have a separate elevator and rudder. The same surface is used for both.
If you hit up elevator, both move up. If you hit right rudder AT THE SAME TIME as up elevator, the tail surfaces move some more moving the nose to the right as it moves up. So you have mixed the rudder in with the elevator input. V-tail mixing. For this reason, the surfaces on a v-tail plane are called rudervators.
Elevon Mixing - On a flying wing, like my Electrajet or a ZAGI, they do the same type of thing only this is elevator/aileron mixing, or elevon mixing. The surfaces are referred to as elevons.
Many of the new non-computer radios include v-tail and elevon mixing now whereas it used to require a computer radio, or the addition of a special mixing device in the electroncis package.
There are other mixes as well. Using a computer radio or a dedicated mixing device, you can coordinate all types of combinations for different effects. These are often controlled with the switches on the top of the radio where stick input will cause a different behavior of the surfaces than you would normally expect.
Coordinated Turn - On power planes and on sailplanes, it is normal to add rudder to aileron input. This is called a coordinated turn and is common to do manually on non-computer radios, but computer radios can be set up to do this automatically.
Coordinated Flaps - You can add the flaps to the ailerons so that the flaps move with, and coordinate with the ailerons The flaps become extensions of the ailerons for more control surface movement. This takes 4 servos, usually in the wings. I think this is called aileron/flap coordination, or coordinated flaps.
Likewise, the ailerons can be made to follow the flaps to multiply the effect of lowering flaps. This requires a minimum of three servos, two on the ailerons and one on the flaps.
Ailerons can act as flaps if you don't have flaps for landing control. These are known as flapperons which is a change in assignment of the surface from aileron behavior to flap behavior. This requires two servos for the ailerons. You would steer with the rudder during landing and/or by variation of flap adjustment from one side to the other, but both sides would be down, not up and down in the usual aileron fashion.
Sailplanes get even more interesting. Some sailplanes require 10 or more channels to handle everything. Especially if they have waggle wings, wings that rotate like ailerons, or full flying stab which means the whole stabilizer moves rather then just the trailing edge.
Spoilerons - You can take spoilers, these reside at the top of the wings, and tie them to the aileron function. Now you have spoilerons or spoilers working with the ailerons. To do this your spoilers require two servos instead of one.
Camber Changing Trailing Edge - On sailplanes they use a mix where the ailerons follow the flaps to move the whole trailing edge down for a camber changing effect, since you essentially change the shape of the wing while it is flying. By lowering the flaps and ailerons together you create a more under cambered wing. You would steer with the rudder here, I believe. This changes the glide characteristics of the plane. Again, a minimum of three wing servos is needed to do this. I don't think this is used on power planes. I don't know if you would ever move the trailing edge up for a change in top airfoil profile.
Sailplanes also have a set-up called "Crow" where both ailerons go up while the flaps go down. This really slows the plane down to help with precision landing.
With the right computer radio you can mix all kinds of combinations. Flaps tied to ailerons with rudder input would be a flapperon coordinated turn, I guess.
Imagine the fun you can have changing between two different launch modes to standard flight mode to several enhanced flight modes, to a camber change to 3 different landing modes.
Think of how long it would take to set this all up for each plane.
Think of all the mistakes you could make with the flip of a switch!
Well, this is what computer radios do. Not all computer radios can do all of these mixes. However when you read the spec sheets, they will usually list Fixed Wing Mixes and Sailplane Mixes. Then, some do mixes for helicopters.
Is this fun or what?
And, you will get a debate on whether you need a standard radio or a computer radio and what mixes come with each. What does that mean?
Here is a short primer on surface mixes. I invite others to clarify or correct my comments and add where these mixes, or others, are used.
V-tail mixing and elevon mixing - These are becoming more common on standard radios, but used to require computer radios.
The term V-Tail mixing comes from the fact that on a V-tail plane, you do not have a separate elevator and rudder. The same surface is used for both.
If you hit up elevator, both move up. If you hit right rudder AT THE SAME TIME as up elevator, the tail surfaces move some more moving the nose to the right as it moves up. So you have mixed the rudder in with the elevator input. V-tail mixing. For this reason, the surfaces on a v-tail plane are called rudervators.
Elevon Mixing - On a flying wing, like my Electrajet or a ZAGI, they do the same type of thing only this is elevator/aileron mixing, or elevon mixing. The surfaces are referred to as elevons.
Many of the new non-computer radios include v-tail and elevon mixing now whereas it used to require a computer radio, or the addition of a special mixing device in the electroncis package.
There are other mixes as well. Using a computer radio or a dedicated mixing device, you can coordinate all types of combinations for different effects. These are often controlled with the switches on the top of the radio where stick input will cause a different behavior of the surfaces than you would normally expect.
Coordinated Turn - On power planes and on sailplanes, it is normal to add rudder to aileron input. This is called a coordinated turn and is common to do manually on non-computer radios, but computer radios can be set up to do this automatically.
Coordinated Flaps - You can add the flaps to the ailerons so that the flaps move with, and coordinate with the ailerons The flaps become extensions of the ailerons for more control surface movement. This takes 4 servos, usually in the wings. I think this is called aileron/flap coordination, or coordinated flaps.
Likewise, the ailerons can be made to follow the flaps to multiply the effect of lowering flaps. This requires a minimum of three servos, two on the ailerons and one on the flaps.
Ailerons can act as flaps if you don't have flaps for landing control. These are known as flapperons which is a change in assignment of the surface from aileron behavior to flap behavior. This requires two servos for the ailerons. You would steer with the rudder during landing and/or by variation of flap adjustment from one side to the other, but both sides would be down, not up and down in the usual aileron fashion.
Sailplanes get even more interesting. Some sailplanes require 10 or more channels to handle everything. Especially if they have waggle wings, wings that rotate like ailerons, or full flying stab which means the whole stabilizer moves rather then just the trailing edge.
Spoilerons - You can take spoilers, these reside at the top of the wings, and tie them to the aileron function. Now you have spoilerons or spoilers working with the ailerons. To do this your spoilers require two servos instead of one.
Camber Changing Trailing Edge - On sailplanes they use a mix where the ailerons follow the flaps to move the whole trailing edge down for a camber changing effect, since you essentially change the shape of the wing while it is flying. By lowering the flaps and ailerons together you create a more under cambered wing. You would steer with the rudder here, I believe. This changes the glide characteristics of the plane. Again, a minimum of three wing servos is needed to do this. I don't think this is used on power planes. I don't know if you would ever move the trailing edge up for a change in top airfoil profile.
Sailplanes also have a set-up called "Crow" where both ailerons go up while the flaps go down. This really slows the plane down to help with precision landing.
With the right computer radio you can mix all kinds of combinations. Flaps tied to ailerons with rudder input would be a flapperon coordinated turn, I guess.
Imagine the fun you can have changing between two different launch modes to standard flight mode to several enhanced flight modes, to a camber change to 3 different landing modes.
Think of how long it would take to set this all up for each plane.
Think of all the mistakes you could make with the flip of a switch!
Well, this is what computer radios do. Not all computer radios can do all of these mixes. However when you read the spec sheets, they will usually list Fixed Wing Mixes and Sailplane Mixes. Then, some do mixes for helicopters.
Is this fun or what?
