If your radio does not support elevon/vtail mixing, and you don't have an external vtail mixer, here is a way to do it just using mechanical setup using two servos

Anwar sab,
Ive attached  a more simple v-tail mixer sucessfully used in disply superman model flown at hyderabad NCC day in 1988. Way too simple.

prabhat

Very interesting !

The superman flown in hyderabad was built by me and had a sliding tray for the aileron servo, the sliding tray being moved by a fixed elevator servo. The sliding rails are fabricated with cycle spokes and the runner on the rails was brass tubing fixed to the servo tray.
Anwar ul Haq

That is great

Any pictures of the setup ?

Great Idea man