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2008 June 4 Added new
harness diagram and flight verbiage after
more testing.
Miniplane has been building PPG engines for a long time, since maybe
1996. They make both the Top 80 engine and the Miniplane paramotor that,
not surprisingly, only comes with that engine. Owner Diego Cecchetto has
made his niche in the lightweight arena. It is heavily engineered to be
lightweight.
The Top 80 engine is used on a number
of other frames and is popular in other countries outside the U.S,
especially for competition pilots where thriftiness is well rewarded.
It's had numerous improvements to tweak both thrust and weight
since it was last used extensively on the Sky Cruiser from 2000 to 2003.
The motor is good but what intrigued me was its harness and
frame—the implementation of a hard point low hook-in harness with
weight shift that that I really like. Miniplane calls it their
ABM system.
It's more of a mid-point hook-in, really, but has nearly as good a weight shift
capability of the low hook-in models.
During Britton Shaw's "Endless Foot Drag" in May, 2008 I got a chance
to fly it. Back April 2007, for whatever reason, I didn't have time to fly it
and, I'll admit, I figured the weight shift was an afterthought—a bow to European preferences. I
didn't even realize it was a low hook-in, hard point attachment; rather
I thought it was just like the weight shift on my Sky Cruisers and
Blackhawk. How wrong I was.
I've flown nearly every hard-point low-attachment machine out there and
have always objected to the fore/aft movement endemic of the species,
especially with thrust changes. Full power tilts you forward, powering
off lets you tilt back. I did an experiment with one such machine and,
by bringing my feet up, I would angle way back. And that was with
the attachment as far aft as it allowed (setting for the lightest weight
pilot). The Miniplane had none of that behavior.
As an aside, while testing a machine whose owner called it unflyable, I
came up with a cure for most of the objectionable behavior and enjoyed
flying it afterwards. Hopefully I'll get an article on that up in
Educational, Chapter 12. It was during the Arizona Flying Circus
where I was given a low-attachment machine to use with the admonition
"If you can make it flyable, it's yours for the weekend." My solution, a
four inch rope worked splendidly..
The Miniplane WS manages to almost completely eliminate fore/aft
tilting, even during power changes from idle to full. It maintains the
best benefits of low hook-in including lower hand position and weight
shift. That is, to me, huge and when combined with other desirable
traits, led me to purchase the machine for my own use.
Weight A well-balanced 46 pounds. You can stand around with this
thing on your back for a long, long time. Leaning over slightly removes
it's pull back.
On June 1, 2008 I ran the motor out of gas, made sure there was nothing
in the pouches and weighed it on my postal shipping scale. For
verification I weight it on a Mustad digital scale and it came out 45.6
pounds. This is the Empty Weight since there may be the minutest amount
of fuel in the bottom of the tank although I can't see any (a credit to
the pickup system and skinny tank bottom). Even so it wouldn't be more
than a couple ounces.
  
Harness & Suspension (-): Very comfortable on the ground and in
flight. This is where the machine shines. Hand position is low like on
most low attachments brands but not quite as low. In fact, it's
perfect!
A few vestigial parts attest to it's
straight-arm origins. The frame-mounted distance bar tubes are still
there. Of course they add necessary strength but a simple support would
shave a few ounces. Also, the over-shoulder harness straps are flight
worthy as if they'd be handling flight loads. But on this arrangement
they're just ground handling straps and could be scaled down to reflect
that use, saving maybe a half-pound. Plus they're more difficult
to adjust than the original ground handling straps.
The original Miniplane harness is probably
the most copied style in all of paramotoring, at least in the U.S.—kind
of like PAP seems to be in Europe. Hopefully the lessons of this new
method of low-attachment will be incorporated and improved on by others,
especially since Miniplane can't make enough frames to go around.
The
harness achieves its nicely balanced higher carabiner pivot mostly
via the special S-shaped bar. But another subtle help is how the
carabiners attach to the bar (2nd harness picture above). That triangular loop
of strap becomes rigid in flight. I watched it. So the carabiner
actually pivots an inch above the arm, further raising the pivot point
without needing to raise the S-arms. This might not have been
intentional, but it sure does work.
The pivot point is very near or just above
the thrust line. You can move the carabiner attachment fore/aft by
loosening a rubber-lined collar on the swing arm then moving the collar
fore/aft and retightening the bolt. I plan on trying it in more aft
position.
Starting (9): Top 80 easy. I've now started it on my back
several times. Reach back and pull upwards. High compression makes the
pull force high and there's no flywheel effect but it's still only an 80
cc motor. There is also a handle with what appears to be a heat shield
although the standard model doesn't have it so I don't really know what
it is.
Ground Handling & Kiting (9): Easy. Feels like other low
attachment systems but with only the weight of a Top 80, so it's quite
manageable.
  
Launch (-): Reverses are a dream. Being light weight makes it
easy to whip around for an almost no-wind reverse inflation.
Forwards launches are slightly more difficult for two reasons. 1) you can't
use much power to help inflate. Using partial power (25% or so) from the
start of a launch improves success, but doing so might flex netting into
the prop if done on a bigger wing. Having said that, I always use a partial power technique and it
works fine but the manufacturer recommends against it.
Secondly, and this one is easily curable, the fabric netting sleeve
tends to slow down or snag the lines. See the picture above. Fortunately
there is a simple cure. Slide about $2 worth of slippery tubing (shown
above) over the hoop's bottom half. Now lines should slide up
easily. I'll do another test and try to get pictures.
    
Getting in can be done without sitting on the ground. I find it
easier to stand up first then buckle the harness but that increases the
chance for forgetting something. Otherwise I do like the series shows
pictured just above.
Climbout (-): Comfortable without any fore/aft wobbling
around. It was easy to get into the seat although I had to let go of one
brake and push down on the seat back. Having tighter leg loops may have
negated the need for that.
There is left/right movement in the weight shift arms but even that
is muted because the frame and seat doesn't move as much as on many
other low hook-in models. I don't mind the left/right movement anyway,
it conveys wing motion that you translate into a feel for the air and
handling. Of course even high hook-in machines with weight shift do this
to varying extent.
Flight (-): A dream. Low hand positions and easy weight shift. This
is the first low-attachment machine I've been able to really like and I
like it a lot.
The motor has been easy to restart for the three times I've tried it. It
takes a good overhead tug with both hands. The rope bottoms out so it's
good to think of using a short, quick burst.
Throttle response is immediate and smooth. A popular myth is that
clutch units take a long time to spin up. That's simply not
true once the clutch is engaged. Even from idle the clutch engages
darned fast. I've had no problem doing high precision maneuvering and
foot drags. That's not just the Top 80, either. I've flown lots of
clutched brands and the majority of them spin up fast provided they're
tuned and running correctly. I fly a belted black devil machine about
half the time so I'm not biased either way, just pointing out
observations.
A minor complaint is that the risers are more in the way for
taking pictures. On high hang point machines it's easier to position the
camera. I've noticed this on all low attachment machines and it's
certainly easy enough to work around.
June 4, 2008
More testing and this time with a pilot who has never flown low hook-in
systems although he has well over 100 flights on other systems. We both
flew it, taking a bunch of pictures to better understand the harness.
This time it was bumpy, probably a solid 3 on the
bump scale
with occasionally more—enough that Tim landed because of turbulence.
There is a fair amount of left/right wobbliness which is part and parcel
of any good weight shift system, but nothing fore/aft.
 On
landing the system does leave you hanging back like most low attachment
machines so you're more likely to fall back in a high wind landing if
not prepared. Of course even high hook-in systems can have this behavior
if set up to hang back. We didn't notice it "scooping" you up on launch,
though, and in fact you have to push down on the back of the seatboard
to fully get into the seat. Tim never got fully back in the seat but
didn't report it to be uncomfortable.
As the picture just above left shows, he struggled a bit with the leaned
back touchdown attitude. The landing was soft but brake position and
angle was different. It's certainly something to get used to but, since
you're moving forward on touchdown, is not a problem.
Weight Shift (-) Weight shift is awesome. It may not be quite as
loose (free) as the Paps or pulley systems but its darned close. I'd
call it at least 95% as effective. It was plenty for me. I love the pulley system
on my Blackhawk but it adds a dash of complexity and weight.
Torque (-):
I was unable to detect any torque turn at all, even under full power on
the Spice.
On a later flight, under a Swing Mistral, it did cause a slow left turn
as you would expect. On my first flight (Spice), I did several cycles from idle to full power and
got no detectable turn. Go figure. So obviously torque is well controlled.
Thrust (-): It's no slouch. Miniplane has eked out more oomph
without over tasking the guts. Primarily this was done through a more
efficient prop and a less draggy reduction drive. The 49 1/4 inch carbon
fiber prop probably adds 2 - 5% over previous machines and the
oil-filled reduction drive probably adds another 2 - 5%. That's a lot.
Consequently, this Top 80 is probably getting 5 to 8% more thrust than my
older ones. I'd estimate the thrust at about 105 pounds.
My climb rate was over 300 feet per minute.
Endurance (-):
Forever. They put a large tank that I suspect would easily provide 3
hours of flying. I'd estimate the fuel burn at 0.7 gallons per hour for
a 145 pound pilot (me) and a moderately efficient wing at 23 mph.
Vibration (-):
Minimal. Nothing out of the ordinary and maybe less than average.
Padding was enough to keep vibration at bay.
Sound (-): Very quiet. Essentially as quiet as the Fresh Breeze
putting out the same thrust. Most of the noise is from the Prop.
 Safety (-):
Some sacrifice is made here owing to the desire for being low drag and
light weight. The frame is minimalistic. It will still provide some
protection in a vertical crash but less than most.
The netting will clearly not stop an open human hand from hitting the
prop at full rated thrust. And the prop extends behind the cage hoop so
it may be possible to get a hand around far enough to be whacked. I
suspect you'd have to be really flailing for that to happen.
A positive design element is how the gas tank is curved near the
bottom. That makes it unlikely to be struck by the prop in even a bad
crash.
Like most harness systems that attach on a hard point there are is a
carabiner back up strap. Same here. It appears that a broken S-arm would
merely drop you into a weight shift turn of a few inches—completely
manageable.
Construction (-):
Welds are sound and finish is good. A radial rods was loose and popped
off during one of many test forward inflations while simulating a gust.
The others are just the opposite and won't come off easily, even when I
want to pull them off. I'm still working on that. Netting, motor,
exhaust and everything else seems very well constructed.
The motor uses parts from an Italian Scooter
but is heavily modified and tweaked both for power and longevity. The
reduction drive looks extremely well made. Being oil filled, it has
lower drag. And that aluminum muffler reduces weight where it's needed
most—aft. It will be interesting to see how it holds up. It appears well
made. In fact, I took a magnet to the machine to ferret out anything
ferrous and came up nearly empty. The frame, swing arms, radial arms and
even the fan cage is aluminum. Someone over there is Mr. TIG.
Reparability (-): If anything breaks you'll need a welder or
Italian parts. The
radial arms going out to the hoop are proprietary, although fiberglass
tape, aircraft safety wire and aluminum tube from the hardware store can
work in a pinch. Don't ask me how I know that.
The netting uses a particularly fine material so as to reduce
friction and decrease the flat area presented to the wind. Lots of thick
netting provides good hand protection at an expense in drag. This
minimizes drag. You can buy the netting also from other sources such as
Marc Damon and possibly Paratoys.
 Transport (-):
At first I was disappointed about this until I started to really look
at it. First, the arms don't just slide out like the Sky Cruiser or Fly
Products. You must remove a bolt. However, if you unscrew the swing-arm D retainer,
which is done by hand, the arms fold all the way up.
Also, and this sealed my fate for purchase, the motor comes off with
4 bolts and a wire tie. That's it. You unbolt, take off the air box
(loosen its screw on the carb) and you're ready to ship it. The throttle
is attached only to the motor. Now the lightweight frame can be placed
in a box with your wind and shipped as checked luggage. The carbon fiber
puzzle prop fits in there, too.
This machine was bought to replace my traveling Snap 100 so being
able to ship it around was important. The frame requires probably a 36"
box to be sufficiently padded but the wing can be used for that, too.
Cost: As European imports goes, it's about average at just
under $5300. The Euro exchange rate hurts. Parts are relatively cheap
and seem well stocked.
Miniplane advertises the WS as their ABM model. It's not being
marketed much but then the machine isn't marketed heavily anywhere, it
seems. A number of instructors are dealers and I encourage you to buy
from them. They do the work, they deserve the business. Overall: Obviously I'm thrilled with the
Miniplane WS, given that I've purchased one. The Top 80 engine seems to have
been improved and the harness is a pure joy to fly. I haven't been this
excited by a paramotor design in some time. Don't get me wrong, I love
my existing machines and there is a lot of good gear out there but this
ability to have low hang points without the fore/aft wobble is good.
Time will tell and, no doubt, I'll update this as I gain experience and
knowledge.
Other comments on the machine from
First Backyard Flight. |
