Re: F1D prop spars

From: john_kagan <john_kagan_at_hotmail.com>
Date: Mon, 15 Feb 2010 03:38:56 -0000

--- In Indoor_Construction_at_yahoogroups.com, "tim.haywardbrown@..." <tim.haywardbrown@...> wrote:
>
> I'm building some F1D props and making some prop spars. I have a few questions re the spars...
> - round or square section?
> - boron... which sides... not at all?
> - most critical... target weight?

Hi Tim,

Below are my notes for my VP prop hubs. If you building a fixed pitch you can get quite a bit lighter, but you might not want to. If you build your fixed pitch props to the VP target weight you'll be all set trim-wise when you make the change.

My VP prop target weight is around .22-.24gm

Hub w/ aluminum bearing surfaces .012-.014gm
Spar half w/ aluminum tab .042-.046
Spars + hub .114

My prop spars are square, no boron. .075"x.080" -> .025"x.025"

You can adjust the sizes to meet the target weights. Also, make a bunch, test them for stiffness, and match similar pairs. Discard the really flimsy ones.
Received on Sun Feb 14 2010 - 19:38:59 CET