BobWoodhouse

What is the spec/size of a HS-81 servo horn screw?

Best,
Bob

A.T.

Screw for resin geared HS-81 = 2.2mm x 5mm as per:
Hitec Screw Set for Resin Geared Servos
In case you also have HS-81MG, the following may assist.
Hitec Screw Set for Metal Geared Servos #55802 "Metal servo Screw Set (5 x short, 5 x long)".
Standard Servo Screws (Metal Gear Servos) 2.6mm x 6 mm & 8 mm to fit
HS-225MG, HS-525MG, HS-625MG, HS-645MG, HS-705MG, HS-925MG, HS-945MG, HS-5245MG, HS5625MG, HS-5645MG, HS-5745MG, HS-5925MG, HS-5945MG, HS-5955TG, HS-5995TG, HS-5996TG, HS-5997TG, HS-5998TG.
The small screws [Five 2.2 x 5 mm Phillip-head screws] fit the HS-65MG, HS-81MG, HS-85MG, HS-125MG.
NB: Never use loctite. In need if star washer is lost, Liquid Thread Lock may be used sparingly and ensure none remains in contact with plastic parts.
Regards
Alan T.
Alan's Hobby, Model & RC FAQ Web Links

MikeMayberry

My Feedback: (1)

It's actually 2.3mm not 2.2mm.

Mike.