A better V-TAIL mix

[Rob Thomson]

The default V-TAIL mix as applied by the templates section of the firmware is IMHO a bit rubbish.

It does not easily enable you to get effective rudder control on the V, without excessive pitching either up or down.

The reasons for this are all hooked up in complex aerodynamics - you simply cant have equal up and down movement on the elevator of a v, and get yaw, without pitch.

Well.. the mix attached addresses that issue.

The rudder/elevator mixes are slaved to some ghost channels, and the elevator has a compensation value on a curve.

All works rather well

[Scott Page]

A+ Thank You

[Alan]

Thanks for this... seeing these snippets is helping me understand the setup of for my full house electric vtail sailplane much better than what any manual can do for me. However, you had me going for a while with all the stray unnecessary settings still in the file such as Curve 1, Custom Switches, Custom Functions and limits on anything but CH1 and CH2 and any offset unique to the original model this was designed for.

So I cleaned it up and added to my library as the following attachment. Also zero'ed out the trims in the "phases"

Thanks again... Alan

v-tail-mix.eepe

(4.84 KiB) Downloaded 617 times

[kaos]

Doown loaded, but I have not tried it yet, if it works so good why not replace the template with this one?

also would this work the same/improve for the delta mix?

[Rob Thomson]

It is not really usefull for the delta.

The 'default' mix is good for really giving a basic understanding of the concept of how to mix.

This one relies on high channels and a curve to allow you to vary the amount of elevator input that is applied when using the rudder. This is important to stop the V tail causing a pitch response, rather than a yaw response.

To add this as the default way of doing things will only complicate things for the 'noob' who is trying to get to grips with things.

[RightRudder]

Thanks for this Rob

I used it as a starting point for an advanced program for my Spectre which is the HK knock-off of the Passer-X. I map the rudder function to a virtual channel where I can use a GVAR to control the weight on mixing a portion of the aileron into the rudder for turn coordination. Then I used your technique to mix that virtual channel into the V-Tail differential. I haven't tried it out in the air yet but hopefully this weekend.

[RightRudder]

Hi Rob

Just wanted to let you know I tried out your V-tail differential idea today on the hobbyking Specter. It was a bit thermally even thought I waited till near sunset and then I had to go but I definitely found that 20 weight was too much with my setup but when I reduced it to 10 it seemed pretty good although I would need to fly it in dead air to be sure of the best setting. When I can do that I'll report again.

Thanks again for posting that.
Joe

[Rob Thomson]

Yup. The final weight really depends on the model in question.!

But not experimentation will sort it for you in short order

Sent from my GT-I9300 using Tapatalk 2

[Daniel]

Why not use differential in the mixer box, by just adjusting the differential %, I just tried it and test flown it on my V tail model and it worked a treat, I am using the V Tail template with lots of other mixes like motor elevator and crow elevator compensations, am I missing something?

[Rob Thomson]

Diff will 100% work.

If I am correct, this mix was made a long time ago, before the differential option existed.



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