Rack and Spur Gear - Help with Maths!

[RPPerry3]

I need help calculating the correct diameter of spur gear so that my potentiometer gets near 300 degrees rotation as it travels the length of a 300mm rack.

I'm building a custom flight yoke and this is for Yaw control.  As I push the yoke shaft in or pull back the carriage will have the Potentiometer with spur gear that rolls down the rack gear as input.

[navymustang]

I assume you meant pitch control 

Have you thought about using a string pot instead of the gear assembly you described. So much easier to build with.

[Trevor Hale]

You could also use a slide pot. That just slides in and out with the elevator pitch control


A lot less complicated.



Trev

[blueskydriver]

Jim's suggestion is spot on. I've been using the same string pots for many years in my TQ. So, those would be great for a Yoke setup, or like Trevor suggests, the slide pots will work just as good...

John

[Aerosim Solutions]

Diameter would have to be 115mm

360/300(degree ratio) = 1.2

1.2 x 300mm = 360

360mm/Pi (3.142) = diameter 114.57mm

Cheers Gwyn

[Trevor Hale]

Diameter would have to be 115mm

360/300(degree ratio) = 1.2

1.2 x 300mm = 360

360mm/Pi (3.142) = diameter 114.57mm

Cheers Gwyn

Gwyn, This is amazing.. you described it perfectly.  Thank you.
Trev 

[RPPerry3]

I know this is very late, but thank you to all who replied.  I had to drop the project.  It was a quiet Sunday afternoon and my wife ran down the stairs waiving the magic wand of disappearing.. . it had two "++" symbols.  Meaning my space for a cockpit and funds would now belong to my (now 2 year old) baby girl.  I couldn't be happier being her daddy and I'm now able to get back into building a cockpit of sorts, but the 738 is far outside the budget and room so I'm considering my second favorite aircraft KA350.