"rich" <cwo4cno7325@[EMAIL PROTECTED]
> wrote in message
news:341db621-0702-471f-9059-94c35c41f53f@[EMAIL PROTECTED]
Jun 11, 8:22 pm, Ted Campanelli <tc...@[EMAIL PROTECTED]
> wrote:
> Ted shuffled out of his cave and grunted these great (and sometimes not
> so great) words of knowledge:
>
> > Hi All,
>
> > Still working on a Senior Telemaster, and am planning on using an
> > OS-61 for power. After getting the wing mounted on the fuze, I'm
> > wondering if a .61 is big enough? Anyway, my question is how big a
> > prop can I use. Prior plane was a 60 size trainer, and I used a 12x6
> > prop, and it seemed to work ok. Do you think I can use a 13x5 on this
> > plane/engine combo??? 12 x 6 = 72, and 13 x 5 = 65 so power seems
> > about the same. I'm looking for take-off performance, not top speed.
> > Maybe even a 14x5 if I found one????? Can you go too far with this?
>
> > Thanks for any input.
>
> The 61 is plenty for this bird - the specs only call for a 45 - 60.
>
> You should be OK with the 13x5.
>
> 2 things you need to be aware with the prop though:
>
> 1. Over revving of the engine. The larger diameter will act as a
> flywheel to help keep the rpms in line even though the lower pitch will
> allow the engine to rev up.
>
> 2. Ground clearance. You should have a MINIMUM of 1 1/2" (2"+
> preferred) between the end of the prop and the ground when the plane is
> level. A lot will depend on if you are flying off of grass or pavement
> and how much flex the landing gear has.
Thanks for the input. I'll check the prop clearence when I get the
gear installed, shoot for 2 inches. I have use of the taxi way at the
air****t, so first flight will be from asphalt. May use the main
runway if I have no guts that day!
I read the specs too, but the thing just seems huge when compared to
the 40/60 size I have flown in the past. BTW, I just finished
installing the functional wing struts today. AL fittings at the fuze
into 1/4 ply, and thru bolted to a main spar, Used faired AL tubing
from Tower, flattened a tad at the ends. Attachment fittings slide
into the tubes with a pin to lock. Look clean and light, and seem
quite strong for tension.
If summer ever gets here, it will be a next season plane, but 12
inches of snow yesterday makes me wonder about that Global Warming
thing.
Rich.....
YIKES!
I used to fly one with a .60 in it and we used it for a glider launch
platform.
The difference between 60 sized trainers and this is the wing.
Watch those struts like a hawk. I have had AL struts work harden and
crack
under load.
Jim Branaum
AMA 1428
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