Unbefrickinlevable. NCFM Bluto review (long)
Ian Frechette
This could be the fastest foamie I've ever seen, or will ever fly.
I saw mention of the Bluto from North County Flying Machines
over on the GliderKing forums as it was spotted DSing
up at Parker, and after seeing the videos of it DSing on their web
site I knew I needed to have one.
http://www.northcountyflyingmachines.com/bluto.htm
I already have an early gen Bowman JW (wing on top of fuse instead
of through it), so that was my basis for comparison. More on that
later. (I also have a 60" Nemesis, so I've got something faster
to compare it to as well.)
The Kit:
Got the kit in about a week ago. It's complete and all the components
are good quality. The instructions are very comprehensive but be sure
you read every paragraph carefully. They may spend a whole page talking
about the spar installation, and only 2 sentences explaining how to glue
the 4 wing pieces together. It's got some trick stuff like the friction
fit tailboom which is removable and rotates in a crash instead of
breaking. It also comes with lead filled brass tubes already pre-installed
in the nose for initial balancing (planks, or which this is very similar,
need the CG forward a lot so often need a lot of nose weight).
Building:
It took me a good 4-5 nights or so to build, which included letting
the glue for the spar cure one night and I accidentally used my
thin basswood strips where I was supposed to use thicker balsa
strips (and then sand down flush with the airfoil) so I wasted a lot of
time building up the resulting depression above the spar with goop and
having to replace the basswood drag spar pieces. I think the
kit could be built in 3 nights if it was done right the first time. ;)
With the excellent advice and tips from Greg Legerton, I also constructed
a 3 3/4" inch long ballast tube starting with a 5/8" brass tube as a
mould, a few wraps of wax paper (should have used a few more), and about 3
wraps of 3/4 oz glass cloth and slow epoxy. Let cure, pulled the tube and
paper off the brass tube and then peeled the wax paper out from inside the
tube and trimmed to length and capped the ends. I then cut 8 tiny grooves
in the end of the brass tube with the dremel's cutting wheel and used the
brass tube as a drill to drill out tunnels for the ballast tube in the two
center wing sections right at the CG (before I assembled them). Gotta
make sure these holes line up perfectly. I made a mistake here in my
measurments and the the ballast tube is 1/8" too far back, so I'm not
sure if it'll be useable without extra nose weight, but the idea was
sound). The tube was then glued into the wing sections at the same time
that I gooped them together and let cure. I then cut out a 1 1/4" by 5/8"
rectangular hole in the top of the wing over and into the ballast tube
creating a hatch. Filled the ballast tube with foam (stuff I drilled out
from before) marked the edges with a marker, put the door back on and
after the wing had been covered, I cut the sides and back out over the
opening and now have a nice little hinged door down into my ballast tube,
that doesn't even need tape over it to stay closed. Thanks Greg.
I then cut some 1/2 and 1 inch long pieces of the brass tube and melted
lead shot into them, using a propane torch and several layers of aluminum
foil in a V (melt lead in foil and pour into brass tubes resting on
a block of wood), and now I have 1 and 2 oz slugs to use for ballast..
I also drilled a very small hole in the bottom of the wing up
into the tube to make it easier to push the ballast slugs and spacers
out of the tube, as it tends to deform a little once the wing is
covered and the covering shrunk, so the ballast is a bit snug
and it can be tricky to extract a 1" long slug from a 1 1/4" long opening.
Otherwise construction was pretty straight forward. Some things take
some patience, but nothing is overly complicated. The instructions
have you covering the center section and only the leading edge of the
outer wing sections with fiber strapping tape. I chose to also cut my
2" wide tape into three long 0.66" strips and used the strips to cross
brace the outer wing sections top and bottom (also on the advice of Greg),
to provide greater rigidity and take out some twist and prevent flutter
at DS velocities Greg also suggested using Goop for most things instead
of Epoxy to better handle DS speed impacts, which I did. I ironed the
strapping tape down smooth, re-sprayed with 3M f77 and covered the wing
with standard covering tape (just easier for me to deal with, especially
on something that's liable to hit the ground hard from time to time).
Black on bottom to remind me of a B2 bomber, purple with flourescent red
flames with yellow accents on top just to be obnoxious as possible.
http://www.houseofthud.com/rc/bluto/blutooutside.jpg
http://www.houseofthud.com/rc/bluto/blutocovering.jpg
http://www.houseofthud.com/rc/bluto/blutobottom.jpg
I plan to make the top half of the tail flourescent red as well, so I can
more easily tell which direction is up. Since the tail sticks both up and
down, it's not always obvious from the side at a distance.
With HS85-MG servos, FMA extreme 5 receiver, and a 600mAh NiCad battery
pack split into a V and put up behind the pre-installed nose weights (to
get the battery as far forward as possible), the CG was only a tick
off and required 1/2 oz of nose weight to balance properly at 5"
from the back edge of the drag spar. All told it weighs in at
22oz. Not light for a 48" foamie but this thing is a bullet.
Flying:
I tried to fly it yesterday but the wind was low. So low my
Zagi was falling out of the sky regularly, and I know I wouldn't have
bothered flying the JW either. At 22oz, it's not a floater.
I did find it a bit twitchy during the couple short flights I had and
that's what prompted me to install the 1/2oz to fix the CG. I had
previously tried to do it with the fingertip method, which they
specifically say not to do. The CG appears to be pretty critical, so do
it right, balancing on the tips of pencils and so forth.
Today the wind picked up later in the day as some nasty clouds blew in, so
I bundled up and trekked up Green Mountain with my JW and the Bluto. I
chucked the JW off first to test the air, and it was perfectly smooth and
fast, blowing about 20-25mph. The JW (my JW at least) doesn't accelerate
very fast but once it gets going it grooves very well, and is *totally*
unflapable in turbulence on the frontside. I won't hesitate to fly the JW
2 feet off the ground at full speed, following the contours of the hill
because I know it won't do anything unpredictable. The JW was doing well
on the frontside with some really huge verticals and a series of about 8
continuous loops. I finally made a couple DS turns over the ridge I was
on, but it wasn't maintaining well on the backside. When I have DSed my
JW its circles have always been relative small because if I spend much
time on the backside I lose too much speed. If the wind on the frontside
is too strong, the JW can lose a lot just punching back above the top
of the hill, and I'm not comfortable flying it too far back behind.
Keep in mind, not every DS ridge has that big fat groove
on top of Parker Mountain. I could have got the JW wound up if I'd
worked on it. Anyway, I brought the JW down, because I knew
the Bluto would fly and that's why I was there.
I threw the Bluto out. It immediately tried to fly back over my
head. Ooops. Too much up trim. Down down down.. It felt a little
slower than the JW at first, but then I was pushing a lot of down
to go fast, so I kept working on the trim. Finally got it trimmed
out reasonably well and it finally started to pick up speed. It seemed
to be overly sensitive to elevator, burning up energy with too much
elevator movement. I eventually realized I had the dual rate switch on
the high rate setting when I thought I'd been flying low. Moved both
aileron and elevator to low D/R and added another tick or two of down
trim and now this beast is accelerating into the wind faster than
any foamie I've ever seen. My 60" Nemesis penetrates that kind of fast,
but there's no way I could fly a mouldie on the pile of rocks that is
Green Mountain.
Over the next hour, as I got more and more comfortable with the
Bluto it just got faster and faster. It is so small, slippery and the wing
loading is high enough that you turn it into a 25mph wind, point the
nose down a degree and it just screams out away from the hill. I'm
not sure I've found its terminal velocity either. I dove it down
from very high up and it was still building speed where the JW would
have maxed out, and that's without ballast. It's very quiet, maintains
well through loops, and stalls gracefully. It accelerates so fast
that as long as you've got a little room you can push out of full
stall and be ready to make another turn in 20 feet or so. The roll rate
is awesome. Because my Stylus TX flies flying wings on channels 2 and 7
(bastards), I had to set the Bluto up as a V-tail. I mixed
the ailerons to rudder at about 60% and then have D/R of another 60% or
so. One interesting quirk of flying this way is that the rudder
stick still causes 100% aileron deflection while the aileron stick are doing
60% or 36%. That means if I want sick rolls, I can throw the rudder
stick full over as I level out of a dive and do like 5 rolls in a row
before it heading for the ground. It will stall however if you pull back
on the elevator hard at speed. I think I'll change my D/R settings so that
high rate is where my low rate is now and low rate is even lower.
Might be useful on the backside.
Compared to the JW:
The JW feels very big compared to the Bluto. It rolls slowly, it
accelerates slowly by comparison, but it will build up a lot of
speed and it's heavy enough to do some nice zooms on the frontside. One
thing the JW does better is bounce up when you pull back on the elevator.
The airfoil of the JW (with its extended flat spot on top) is designed to
prevent stalling at high speeds and high angles of attack. It shows.
The JW can be in a full dive and you can just haul back on the stick and
it'll do loop inside of 30 feet. When making a tight turn on the
frontside, the JW just bounces off the turns. It feels like it's on a
rubber band when you pull on the stick. In fact, it seems to lose less
speed the harder you turn. A bit gradual turn away from the hill
and the JW will slow down. And as I said, the JW is unflappable.
Nothing flies through turbulence as well as the JW.
The Bluto is, I think, faster. I'm not totally sure yet. I need to get
someone to fly my JW next to the Bluto to be sure. With ballast
I *know* it'll be faster. It reminded me of my Nemesis in the way I could
cover an emense amount of sky in a short time looking for the best lift.
It's lighter, and bounces around in turbulence more but it's so fast that
it punches through it where other foamies would need to work harder to
stay upright (like my Zagi and Scooter). It's *way* slippier than my JW
and even though it shouldn't have the weight to do high zooms it seems to
pull it off anyway through sheer slipperiness and wing loading. I compare
it to my Bowman Scooter in this regard which is 36" span and ballasted to
19oz will penetrate into a 45mph wind, but it just doesn't have the weight
to do a good zoom. From a big dive the Bluto will pull up at the bottom
and get small again going straight up. Awesome. Overall the frontside
performance is well superior to the JW, although it's a bit harder to fly
close to the ground, something the JW has spoiled me with. I might
be able to fix this with lower D/R settings.
Compared to the Nemesis:
Is it as fast as the Nemesis? Of course not. Can it fly in 10 times
as many locations, and in nastier winds? Absolutely. It rolls about
twice as fast too, at any speed, and I feel a lot more comfortable
turning against the hill and flying close. Too bad the Bluto
doesn't make the screeching noises the Nemesis does.
Backside performance:
Well, it being my first couple flights, I didn't really punch it
over the back much, intentionally. I lost it over the top once
by accident and it went down out of sight, unscathed. Let's hear
it for EPP. I had tried a couple turns over the back before
the trim was right and it came out all right but no faster than
the JW. I stayed on the front until the sun was well down (flew till 5:30)
and then I discovered just how slippery it was with proper trim. It took
me 5 minutes to slow it down enough to get it on the ground in one piece
(getting darker by the second). I kept flying further and further over
the back until I was pushing into the rotor and then the silly thing would
drop down, then ride the rotor wash up the back and pop out over the
front, over and over. At one point I made like 3 turns 75 feet behind the
hill trying to slow down, and still ended up out front. The JW would have
slowed down and dropped out (had done so earlier in fact). It's twitchier
than the JW at speed, but it penetrates upwind so much better I think it's
going to be an awesome DS machine.
BTW, one of the biggest reasons I think it's slippier than the JW,
besides its thin wing, is that there's no fuse. The fuse
of the JW is a big old blob of foam and covering all
the compound curves was a pain, and the covering tends to get
chewed up with repeated landings. The Bluto has no fuse. It's easy to
wrap the center part of the wing and it should take repairs easily.
The only downsides to this thing are that it doesn't fly in
very light wind (although neither does the JW), and it is actually
pretty tricky to land. It is EPP though, so it's not going to explode
on impact. On the upside, the tail boom rotated as
designed each time it landed hard. Sticking down like it does, it
really has to or you'd tear up that coroplast.
I took detailed build photos as I went along, so I'll have
those posted eventually on my web site and I will post here again.
ian
Ian Frechette
to my construction photos and tips for the Bluto.
http://www.houseofthud.com/rc/bluto/
ian
Michael Goldston
plane. I think I know what my next wing will be.
Mike
"Ian Frechette" <frec...@rintintin.colorado.edu> wrote in message
news:a3nnfn$kou$1...@peabody.colorado.edu...
Derek Choice
Many thanks again! It sounds like your Bluto could still be a tad
nose heavy... if it's not crankin' the turns faster than just about
anything you've seen, it's probably a slight positive CG. On a big
slope like where you're flying, about the only place that it would be
noticable IS on the turns.
Try taping a 1/4 - 1/2oz weight on top of the wing, aft of the CG, and
try a few test flights, moving it farther and farther back each
flight, until it becomes almost unflyable... then squeak it back
forward a tad and it the plane should absolutely open up and shred on
the turns. When you're there, you'll know it!
Also, on your Stylus, are you using the Glider Card with your V-Tail
setting? I kind of sort of think I might remember that I almost heard
somewhere that you can remove the card and select "Delta Mix" from one
of the Power Plane templates, and get full functions on the right
stick, with individual travel adjustments, etc. ? I could be very
wrong, but it may be worth a shot...
Awesome covering job on der Blutus!
:)
dvc
www.northcountyflyingmachines.com
North County, Earth
frec...@rintintin.colorado.edu (Ian Frechette) wrote in message news:<a3nnfn$kou$1...@peabody.colorado.edu>...
Ian Frechette
Derek Choice <fli...@northcountyflyingmachines.com> wrote:
>Howdy Ian...
>
>Many thanks again! It sounds like your Bluto could still be a tad
>nose heavy... if it's not crankin' the turns faster than just about
>anything you've seen, it's probably a slight positive CG. On a big
>slope like where you're flying, about the only place that it would be
>noticable IS on the turns.
I'll play with the CG some more, but I think it's just a different beast.
The Bluto will almost literally fly circles around
the JW on the frontside. But the JW with some airspeed can
pull a hard turn in about half the space with almost no
energy loss. That's what it was designed to do. The Bluto flies very
very fast, and the ailerons can be manhandled for some awesome rolls, but
the elevator needs to be handled more gently or it slows down. Oh, and I
did fly it inverted and it requires only a minimal forward push on the
stick.
In other news, I played in 40-45mph sustained winds
today. There aren't a lot of foamies that'll actually fly all around
the sky in a 40mph wind unballasted. I was doing
downwind loops and stall turns while most folks were just
pointing their birds downhill. I flew the JW to compare, (even cleaned
up the skin a bit the other night) and it's confirmed, the Bluto is faster.
A couple other gliders there. A foamie warbird was just maintaining and
eventually pounded itself into the face detaching the wing. A
Bowman Super Scooter was doing pretty good, but I could out
penetrate, out climb and out zoom it easily. He was able to fly
a bit closer to the hill comfortably though. The Zagi didn't launch at
all. When the winds picked up to 50+mph with gusts over 60 (local weather
station says it recorded a 59mph peak on the flats below the hill),
everyone else packed up and went home, while I put 4oz of ballast in my
tube and continued flying. Eventually the wind got the better of me (cold
temps and dust in my eyes, and inability to stand up) and I went home.
I'm not sure where the upper limits of the Bluto are windspeed wise, but I
haven't reached em yet. Now I'm curious to see how it flies against your
average slope crunchie. And I haven't had a chance to explore the light
lift performance yet.
ian
Jens Peter
weight of approx. 22oz... With ballast, who knows how well the
'Scooter would do...?
--- Jens Peter
frec...@rintintin.colorado.edu (Ian Frechette) wrote in message news:<a4254j$eq4$1...@peabody.colorado.edu>...
Ian Frechette
Jens Peter <aar...@diac.com> wrote:
>Ian, don't forget that the Super Scooter was flying unballasted at a
>weight of approx. 22oz... With ballast, who knows how well the
>'Scooter would do...?
The Super Scooter is specd at 26oz. 22 is building it pretty light
given its 49 inch span and a lot more foam to cover than just a wing.
Anyway, what's remarkable about the Bluto is that mine, even built heavy, is
22oz unballasted which puts the wing loading at only 8.4oz/sq-ft
and it's still that much faster than the Super Scooter in the same
wind, and the SS is no slouch. Putting 4oz of lead in the Bluto only
increases the wing loading to 9.9oz/sq-ft, but it still flies around in a
60mph wind, and leaves my 13oz/sq-ft JW and ballasted 14oz/sq ft 36"
Scooter for dead. I've got room for about 3 more oz in the ballast tube
for 7 total. First day I need that is going to be an experience
for sure.
Check out the latest video clips over at North County Flying Machines.
http://www.northcountyflyingmachines.com/videoclips.htm
Those aren't exactly foamie sized DS circles, as I found out
myself last weekend in a 100 yard wide DS bowl that suddenly seemed
a bit small. It's not exactly mouldie speed either, but it's good
practice and much lower pucker factor. I'll get my 60" Nemesis on the
backside one of these days.
Winds are supposed to pick up later this weekend here. I
can hardly wait.
ian