Re: Carved Prop Calculator
I've long been interested in building some larger outdoor rubber models
like a Mulvihill, but carving the prop is intimidating. This spreadsheet
could be very useful. Maybe I'll make an attempt this winter. Thanks for
sharing.
On Fri, Aug 19, 2016 at 11:01 AM, rbharlan_at_comcast.net
[Indoor_Construction] <Indoor_Construction_at_yahoogroups.com> wrote:
>
>
> A modeling friend asked me about carving props and mentioned he was
> interested in trying one. He flies mostly FAC scale events, so I though it
> appropriate to contribute something here. The biggest starting hiccup with
> props is to figure the block size after deciding on the prop diameter,
> pitch and shape. I've carved a few blocks that were a bit too narrow to
> contain the blades that I wanted. So I decided to write a spreadsheet that
> would help design a block that would let me get my prop.
>
> I have supplied two versions, one for Excel 2010 and one for older
> versions, 2003.
>
> To use it, design your prop, choosing diameter, pitch, max blade width and
> radius for max blade width. Then guess a block width. Something a bit
> smaller than the max blade width is a good place to start. Enter these
> values in the shaded cells of the spreadsheet and it will calculate all
> sorts of parameters. The block shape is the kind with a fixed width in the
> outer 40% of the blade. The spreadsheet lists ten block chords that can be
> compared to the blade shape to see if the initial block is wide enough. If
> there isn't much margin to adequately cover the blade, a second guess for
> block width can be entered and a new set of chords examined. When the blade
> fits, you then can lay out the block to get the right triangular shape for
> the inner part of the block and the right curves on the sides of the block
> where it has constant width.
>
> I'll be interested in reading comments about the calculator.
>
> Ray
>
>
>
Received on Fri Aug 19 2016 - 14:00:30 CEST
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