OK......this may be basic to a lot of you, but spinner size selection has always been a mystery to me.
How do you determine what size spinner to use with what size prop and what size engine. Same goes with prop hubs. There.....it's as simple as that........please explain to me so I know what I'm doing
in the future.

Thanks,
Andy

the basic formula is 20 to 25% of the diameter of the prop.....but it is also up to you and what will fit your airplane the best....
depends if there is a cowl etc. etc.

but I have found the 20/25% rule gets me in the ballpark to start looking

I've always picked the size that would "Flow" into the rest of the plane and not worried about any formula. This has always worked for me.

Bill.

Hello!
Selecting spinner! Pick whatever fits the fuselage shape...it is that easy.

Regards!
Jan K
Sweden

Well, it depends on what type of plane. If it's profile, then any spinner will be too wide, and it's best to use a hub to save weight.

For a radial cowled scale plane like Sukhoi or Zero, just try to find a real aircraft's picture, and try to estimate the ratio of spinner diameter to the cowl diameter.

Thanks to all that replied. I was just worrying..or concerned that too big a spinner would
tax the engine and make the pulling power of the prop diminished.

Andy

yeah all the spinners i have had really tend to flow rather well into the aircraft right after they hit the ground mr robison!!

Hey Tinman!!

You're just jealous because your spinners seldom last more than one or two flights.

Haw.

Good to hear from you again.

Bill.