Servo horn extension for 25T

Strong servo horn extensions that fit over typical 25T aluminum servo horns that come with many common servos.

I designed this to maintain the strength of the metal spline connection (keeping the aluminum, rather than relying on printed plastic) while providing a long extension.

Arm radii (distance from center of hub to each mounting hole):
shorter extension-- 44mm, 52mm, 60mm, 68mm
longer extension-- 68mm, 76mm, 84mm, 92mm

Hole sizes: all holes are M3 (clearance). I recommend M3 x 8mm for the hub and arm screws.

Thickness of the arm is 8mm, so if you're using screws in the mounting holes, you'll need longer ones for that.

Similar extension for 18T size can be found here:
https://www.thingiverse.com/thing:7225260