Yes, my wing design would use the same motor. Same everything. The two
wings should be interchangeable. Just strap on the new wing and give it
a go.
It's not going to change an ESnipe into a Slow Stick. The wing loading
will be the same. But it might handle a bit better at the slow speed
end of the flight envelope and have more performance in the turns.
Cheers,
Tom
On 4/13/19 11:09 PM, ORCA@xxxxxxxxxxxxx wrote:
At our last club meeting I suggested to John that he should come up with a slower version of the E-snipe that would fit our new field.
A week ago I flew my E-snipe around the field as if in a race. Both from a racing prospective and more importantly a safety item, the new field is too small for our current E-snipe racing. We need a depth (from the pits and pilot stations to the East). Maybe when we remove the alders to the East (opposite the pits) and the two trees to the South we may have more room.
Tom, would your design use the same motor? Or would different motor and/or prop be needed? Really like your CAD work - makes me envious.
Rick
-----Original Message----- From: Tom Speer
Sent: Saturday, April 13, 2019 5:10 PM
To: orcachat@xxxxxxxxxxxxx
Subject: [orcachat] Alternate ESnipe Wing
When Richard and I were at John Castleman's, I heard there was interest
in an alternate wing design that might make the ESnipe easier to fly at
our field. The need is to be able to fly slower because the constrained
space from all the trees. I've come up with a wing that might be an
improvement, although it's not likely to make the plane dramatically
slower. For that, we'd have to make the plane dramatically lighter.
The wing I've designed is the same area as the stock wing, has the same
root chord, and the same c.g. location. This means the tail is still
sized adequately and the new wing would be a drop-in replacement for the
stock wing, with no other modifications required. The difference
between the two wings is my design is tapered instead of being constant
chord, and I've used the taper to extend the span. The stock wing is 40
inches long and this wing is 53.4 inches long.
I've also designed a new section shape for the tip. Even though the tip
is half the chord of the root and is thinner, it still uses the same
trailing edge stock for the aileron, without any taper to the aileron.
Compared to the Clark Y, the new tip section has a somewhat higher
maximum lift and a more positive zero lift angle, so it effectively adds
washout to the wing, even when the the bottom surface is built flat.
The tapered wing will have a more uniform downwash distribution along
the span with a lift distribution that is closer to the elliptical
ideal, so it makes better use of the area than the stock rectangular
wing. This will give it a lower stall speed. But the taper is not so
extreme as to cause the tips to be loaded so much that tip stall will be
a problem. The increased span will cut the lift-induced drag by over
40%, making the plane better in the turns.
Other than having to set up to cut a tapered core, the new wing would be
built just like the old wing. Probably the most difficult change to the
build is it would require a tapered spar. Otherwise, it would go
together just like the stock wing.
I've uploaded plans for the new wing to
https://www.dropbox.com/s/v8bd6u8y1mee1r3/ESnipeLongWing.zip?dl=0.
Cheers,
Tom Speer
