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Plane: J2 - Junior Replacement
Junior (Rampus Racing Machinus)
Junior Stats
length 29.5"
b 36" (RG-14)
S 194.4 in2
TVC .37
weight 32-40 oz (8oz ballast)
AR 6.7
wl 30oz/ft2
sl .89oz/ft
J2 Stats
length 29.5"
b 37" (Ayers 6014)
S 199 in2
TVC
weight 44oz, 58oz (ballasted)
AR 6.9
wl 30-41oz/ft2
sl 1.2oz/ft
Wing Root chord 6", tip chord 4" straight trailing
edge, stab span 10.5"(3" root, 1.125"tip - tip
centered in root), c.g 2" from leading edge, c.g to 50%
stab = 13", stab set 1" higher than wing on vertical
fin (5"root, 2.375"tip, root/LE angle = 55 deg)
Fuse in mold half. Fuse is a shortened
version of the revised inland sloper (Woody). 27" long -
16 oz.
Pieces parts. Canopy and mold are in the foreground.
Joining the wing.
Positive 3.2 satin with kevlar hinges. The plan is
to have a rough surface finish that will hold a boundry layer.
The finishing layer of this wing will be a thin layer of air.
Finished - details
Flying impressions.
I have around 15 hrs on this little guy in various conditions.
From 65 mph+ at Pacifica to 25 mph at Rattlesnake (Berkeley Hills)
to 35 mph at Red Rock in Reno (4000' elev). First I have to say
that Don Ayers has a winner with this foil. Not only is it thinner
and faster than the first Junior, but flies in lighter wind and
can carry a LOAD of ballast while being forgiving of my building
accuracy.
At a cliff type site is where this plane is in its best light.
Being small, launches by yourself are uneventful in even the
highest wind and landings are very controllable in the tightest
landing zones. If you do get out of shape on the landing you
only have 44 oz hitting the ground instead of 6-7 lbs or more.
It either sticks, bounces or cartwheels - all done lightly. Being
small also allows for a blistering roll rate if you want it.
At this point I'm still getting adjusted to the speed ... the
roll will be added later. The original Juniors roll would go
from mild to uncontrollable (Blur).
I ballasted it up to 41 oz/ft^2 in a 35mph wind at the coast
and was presented with a new level of speed. This little bugger
can really go. You'd think that a small plane would suffer on
the punch ...but that is not the case. It will punch until it
becomes VERY small. Think about it - with some practice your
punches can be limited by your eyesite ...perfect. On the downline
is where the size becomes another benefit. The acceleration is
exhilarating. You can outpunch some planes by 30'+ and still
pass them through the flat.
At the Red Rock site the lift was less vertical and at altitude.
Although the performance was lacking compared to the coast, the
plane was far from dogging around. I got the slope juice going
and thats what its all about. You can really chuck a small plane
when launching. This instant airspeed is invaluable at a site
like Red Rock where the launch is shallow and out over a granite
boulder field.
I've also DSed this little guy at Rattlesnake - NOT recommended.
Big planes rule for DS, little heavies are the ticket in high
compression locations.
Next time around I'm going to try a peal-ply finish in the
bag. That positive layup was a pain, less uniform and produced
small trips at the kevlar hinges. Internal ballast is another
challenge. I'll stick with the flying stab. It allows me to fly
a little nose heavy and still have elevator control at low speeds.
This is a cheap project that has definately yielded the biggest
bang for the buck, and the most speed/oz.. Throw one together
and let me know what you think. I'd also like to hear of your
improvements. Coincidentally with a slightly larger stab the
surface loading could easily drop under the FAI limit while sporting
a 30 oz/ft^2 wing loading.
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