Mixing Elevator and throttle on DX7?

[Davethebluessinger]

Hi Folks,
I maidened my Mini Mach racer (elevon delta) today with the help of a friend who threw the plane.
It's evident that the plane needs up elevator at launch that can be removed in flight.
I'm thinking that I'd mix elevons with throttle so that at launch I can have 75% throttle with up elevator that I can remove with a switch when the plane is airborne and high enough for me to have a margin of error.
Is there any way I can achieve this with the DX7?

all advice appreciated!

[hayofstacks]

You can on the dx6i in the regular mix settings. Most planes require a bit of elevator to get airborn though.

[Davethebluessinger]

I think it's a typical delta, they all want to dive at launch, I just need a mix for launch that I can turn off as soon as I have enough altitude to fly her on normal settings!

[JetPlaneFlyer]

Sounds like it's excessively nose heavy to me?

[Davethebluessinger]

Hi Jetplaneflyer,
I checked out the CG on the forums and everyone recommends 145mm back from where the wing leading edge intersects the fuse. It's spot on. once I get her airborne she flies beautifully at all speeds. I want to be able to hand launch the plane myself, a mix or flaps setting that gave a little up elevator would be really useful!

[hayofstacks]

You should be able to do either one in the mix, or flaps settting. A flaps switch that isn't porportional to throttle, a mix setting that is, as long as you have a mixer for the tail, or you could put a bit of up into it as you launch it. I just see it as another switch this if its in the wrong position wcould make me crash.

[JetPlaneFlyer]

Dave,

If it flies perfectly at all speeds then it seems odd that it dives when you launch?

I tend not to get too hung up about where it balances, at least after the maiden, its how it flies that's the key thing and if it drops it's nose a lot when you slow up (like in a landing approach or launch), and you need lots of up elevator to stop it diving , then it sounds nose heavy.

[flydiver]

I've mixed in a bit of elevator on the [Gear] switch. It's on when I launch, then I just flip it off. Easy to see when you have it working. Only takes a tad on my Funjet. Easier than mixing with the throttle.
That's more useful for planes like the Radian that climb like crazy as you increase the throttle.

[Davethebluessinger]

Hi Flydiver, sounds like just what I need! Never set up a mix before - any pointers?

[flydiver]

I'm using the JR7202 but the DX7 is essentially the same platform so this ought to work.
Go into programming mode. Scroll to [Prog Mix 1]
These are my settings-you might use slightly different ones for a different plane.

Gear > Elev ON
Rate: 0%
- 9%
SW: ON
Offset: 0

Toggling the Gear switch I can see the elevons moving up and down a couple degrees. Doesn't take much, but that's the Funjet.

[Davethebluessinger]

Thanks Flydiver, I've programmed it in and it's working. I'll try her out later and report back.

Dave

[flydiver]

That kind of programming can be useful I programmed one of my elevon slope planes to respond to elevon changes on the throttle channel. I could tweak the elevon position rapidly and easily depending on weight, wind, and ballast during launch and flying. Pretty handy.
I started out using the Gear switch as described for launch as the launch speed was so much higher than the flying speed the elevon position made a big difference.

[Davethebluessinger]

Worked like a charm, initially I had too much elevator so after the first flight I reduced the percentage. Hand launching is now really easy and controlled. Thanks again!