Trimming an Aerobatic Model

[The Dirt Doctor]

Guys, some, if not all, aerobatic models require mixing out of proverse (or adverse) roll when rudder is applied. Also, there is some interaction with elevator when rudder is applied. Both the JR 10X and 12X have built-in programs to allow one to easily do the required mixes. However, both radios have a means to turn the mixes on and off at will if the pilot chooses.

My question is this - once you go through all of the time and effort to get your model perfectly trimmed out why in the world would you want to turn the above mixes off?

Bobby aka TDD

[jmoesdad]

IM NEW AT THIS BUT...SOME OF THE MIXES ARE NOT FAVORABLE ALL THE TIME IE. DOWN ELEVATOR AT IDLE. IT WORKS WELL ON A DOWN LINE, NOT SO WELL ON LANDING.

[Wayne]

	Quote: Originally Posted by The Dirt Doctor
	My question is this - once you go through all of the time and effort to get your model perfectly trimmed out why in the world would you want to turn the above mixes off? Bobby aka TDD

You shouldnt.
Leave the mixes on.

The only one I turn off is the throttle to elevator on landing.

[Scott Gerber]

Couldn't you just put a piece of duct tape over the switch...????


Scott

[The Dirt Doctor]

	Quote: Originally Posted by Wayne
	You shouldnt. Leave the mixes on. The only one I turn off is the throttle to elevator on landing.

Thanks Wayne. I did not mention the throttle to elevator mix because program no. 64 does not have that included - only the rud-ail and rud-elev.

It just did not make sense to me to turn off the rud-ail and rud-elev mixes once you get the plane trimmed out!!

Bobby aka TDD

[Al Lewis]

Okay, let's say the plane pulls towards the gear on knife edge. So you mix in some up elevator and maybe a little aileron to hold it in a perfect knife edge. Now you're flying your "straight and level" to your next maneuver in IMAC with a slight side wind and need a little rudder to hold a straight line. Probably not going to want that up elevator when you apply the rudder huh???

[Flatlandman]

	Quote: Originally Posted by Al Lewis
	Okay, let's say the plane pulls towards the gear on knife edge. So you mix in some up elevator and maybe a little aileron to hold it in a perfect knife edge. Now you're flying your "straight and level" to your next maneuver in IMAC with a slight side wind and need a little rudder to hold a straight line. Probably not going to want that up elevator when you apply the rudder huh???

The thing is that the plane is gonna pitch to the gear when given rudder weather its in knife edge or lvl flight so the up ele that you mix will continue to keep the straight and lvl line when right side up. This is the way my plane reacts with the mix on all the time.

[zzw26n]

	Quote: Originally Posted by Wayne
	You shouldnt. Leave the mixes on. The only one I turn off is the throttle to elevator on landing.

Wayne,

Almost the same line of thinking, but, do use a Throttle Curves? on all your Gas Engines or just some set-ups?

Ward

[prizzy]

You will find, that if it's trimmed with up el at knife edge, and it's perfect, on level flight, even with that mix on, it will still dive a little. It helps though.

[Flying freak]

Could you not put the down elev mix so that its active when you have your idle up switch on, this way when you land (naturally going into your 'low' idle) you remove the down elevator mix?

Steven

[The Dirt Doctor]

	Quote: Originally Posted by Flying freak
	Could you not put the down elev mix so that its active when you have your idle up switch on, this way when you land (naturally going into your 'low' idle) you remove the down elevator mix? Steven

I believe you are mixing (no pun intended here) up things up a bit. There is proverse roll and diving with rudder application. The 10X has a built-in program (#64) that lets you mix out the rud - ail and rud -elev separately in both directions to get a perfect yaw only response with rudder application and, if I'm not mistaken, the program is also somewhat throttle dependent. That doesn't mean that you still may have to mix a little down elev with the throttle at low idle to allow perfectly verticle downlines. I ussually put that on the switch on the top right back of the TX and turn it on after takeoff and off before landing.

Bobby aka TDD

[Wayne]

	Quote: Originally Posted by Flying freak
	Could you not put the down elev mix so that its active when you have your idle up switch on, this way when you land (naturally going into your 'low' idle) you remove the down elevator mix? Steven

That is exactly how I do it.

Ward,
Mufflers. No curve.
Cannisters, a little bit.
Pipes, I'll let you know when the Godfrey flies but I am sure it will need some.

Al,
Its not a Knife edge mix as people call it. Its a rudder mix. Anytime you need rudder, you will benefit from a proper mix to elev and ail.