Le Fish Open Source Aerobatics Glider Wiki
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Mad Stab: Push-Pull Linkage[]

Push-pull-stab

Steve Lange's push pull setup

Mad-elevator-up

Dawson Henderson's original push-pull mad elevator setup... now using a pull-pull pulley system

A

John Scahill's push-pull Mad setup

You can achieve a "Mad" stab results, such as flips, using a push-pull linkage setup. However it is difficult to impossible to get a full 90° of throw... especially in both directions.

Here are some examples of gliders that use a push-pull linkage... and can do flips.

Some things to keep in mind...[]

You will need to use a large servo horn and a relatively smaller stab horn to get large Mad throws. 

Keep the linkages as short as possible. This will help keep things tight and responsive. However this will put your servo way behind the CG and may necessitate adding nose weight... especially for super light builds.

Use a good quality servo. You want as much resolution as you can get! Dial in a lot of EXPO to tame the Mad movements.

Since it is impossible (?) to get a full 180° of elevator throw with a push-pull setup, a good compromise might be to create the linkage geometry so full up elevator gets you as much throw as possible (90°) and full down is less than that. This way you are sure to be able to do back flips.

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