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Old Apr 18, 2012, 10:04 AM
Addicted to 3DHS and EF
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ohio
Joined Oct 2010
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How do you mix a plane?

I want to learn how to do mixing, I have an Hitec A9 and want to know what is a good way to learn about how to mix a plane? I can do rolling harriors and all that, but I have never been able to figure out mixing and think it is time to learn. I belive it is time I take full advantage of my radio in order to take my flying to the next level.
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Old Apr 18, 2012, 10:15 AM
Extremely Twisted
cwojcik's Avatar
United States, NH, Epping
Joined Oct 2005
2,641 Posts
Do a blender.

But seriously, add in a programmable mix to correct unwanted behavior. That's it. Does the plane pitch towards the belly when you give rudder in KE? Add a mix for rudder->up elevator. Start at 2% and work up until it doesn't exhibit the unwanted behavior. Rudder->aileron mixing is also helpful sometimes. Start at 2% and work up (or down) until the issue goes away. Typically rudder->elevator and rudder->aileron mixing is all that's required on a good airplane (and on certain planes the coupling is so little that the mix is very optional). Aileron differential is also useful sometimes if the plane does not roll axially, but again, it's rarely necessary.

Also, a lot of times you will still have to correct with your thumbs in high-alpha KE even with mixing.
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Old Apr 18, 2012, 10:51 AM
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United States, IN, Fort Wayne
Joined Nov 2008
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Quote:
Originally Posted by 3Daddict View Post
I want to learn how to do mixing, I have an Hitec A9 and want to know what is a good way to learn about how to mix a plane? I can do rolling harriors and all that, but I have never been able to figure out mixing and think it is time to learn. I belive it is time I take full advantage of my radio in order to take my flying to the next level.

IMO, the first thing to do is get the cg set correctly and where you want it. Most of the 3dhs planes for example will need zero mixing when you obtain the intended CG. You should set the CG by trying to get rid of KE coupling. If the plane pulls to the canopy, then it is nose heavy. If the plane pulls to the gear, then it is tail heavy. Keep moving the battery until you can get closest to zero mixing and see if you like the way the plane feels. I don't do any mixing because I set my cg so that the plane has zero coupling and I like the feel of that specific CG.

If you find that "intended" cg but you don't like the way the plane flys, then move the battery to where you like the feel of the plane and then mix out the coupling.

For mixing, you will need a mix that has rudder as master and aileron as the slave. And you will also need a mix that has rudder as master and elevator as the slave. If I remember correctly, those are stock mixes in the A9.

Now you flythe plane and see what it needs. Change the percentages in the mixes only by 2 or 3 each time until you get it were you want it.
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Old Apr 18, 2012, 12:29 PM
Addicted to 3DHS and EF
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ohio
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Quote:
Originally Posted by joesmith285 View Post
IMO, the first thing to do is get the cg set correctly and where you want it. Most of the 3dhs planes for example will need zero mixing when you obtain the intended CG. You should set the CG by trying to get rid of KE coupling. If the plane pulls to the canopy, then it is nose heavy. If the plane pulls to the gear, then it is tail heavy. Keep moving the battery until you can get closest to zero mixing and see if you like the way the plane feels. I don't do any mixing because I set my cg so that the plane has zero coupling and I like the feel of that specific CG.

If you find that "intended" cg but you don't like the way the plane flys, then move the battery to where you like the feel of the plane and then mix out the coupling.

For mixing, you will need a mix that has rudder as master and aileron as the slave. And you will also need a mix that has rudder as master and elevator as the slave. If I remember correctly, those are stock mixes in the A9.

Now you flythe plane and see what it needs. Change the percentages in the mixes only by 2 or 3 each time until you get it were you want it.
All I fly is 3dhs, and my 51'' in KE pulls hard to the landing gear. I can correct it with my thumbs but it does require a lot of up elevator. I have not messed with the CG much, so I will give that a try. Thank you.
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Old Apr 18, 2012, 08:44 PM
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TG43's Avatar
Glens Falls, NY
Joined Apr 2010
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Quote:
Originally Posted by joesmith285 View Post
Most of the 3dhs planes for example will need zero mixing when you obtain the intended CG.
Well that's a really interesting statement to me. You're the first good pilot I've heard say that. I think you really just fly it out, lol. Just for kicks though, I'm gonna try taking the mix out of my 42" slick and see if I can get it to knife edge without any coupling.
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Old Apr 20, 2012, 12:40 AM
They Call him Dead!
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United States, SC, Pawleys Island
Joined Jul 2003
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Check my blog for an in depth list of instructions on how to "set Up" a plane.
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Old Apr 20, 2012, 10:47 AM
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Joined Apr 2008
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I performed the same steps as recommended by Dead, except I performed thrust line before CG. So my steps are thrust, CG, ail diff., KE mix (rudd/elev then rudd/ail). It took a few days for me to trim out one of my planes due to the fact that I'm new to plane 3d and learning to see how the plane reacted with stick inputs.

There is a good debate regarding mix or no mix. After talking to the no mix guys at the local fields, my impression is that they are too lazy or just don't know how so they just fall back on the "just learn to fly it."
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Old Apr 20, 2012, 01:28 PM
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Joined Nov 2007
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Incidences are also important to trimming our planes. If you properly adjust thrust angle, wing and stab incidences, lateral and longitudinal balance, you can reduce or eliminate the need for cross control mixes on a well designed plane.
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