FLPHG Technical Information
Details and links to technical information relating to power
harnesses.
Wind Drifter Home
Bar Position - Many newcomers to flphg are confused by the
apparent change in control bar position. Even with power off, the
control bar will be almost a foot further back than you are used to
when free flying. Nothing about the glider or how it flies has
changed. What has happened is that, with the weight of the engine
below your feet, the CG (center of gravity) of the pilot and harness
are lower on your body than without the engine. With no pressure
on the bar, the CG will be directly beneath the hang point. Thus,
it is your body position that has moved forward relative to the hang
strap. This is graphically illustrated in this CG Comparison CGComparisonS.jpg. Note that
vertical
lines are drawn through the hang strap and at the shoulder, and the
relative distance between these lines. With power applied, the
apparent control bar position changes even more. That is because
the thrust at your feet is rocking your body forward through the
control bar frame.
Bar
Position Changes With Power - The above applies to
the engine being off. Now, what happens when the engine is turned
on? What happens to
the control bar position when you add power? Think about
if first, before reading the explanation: Control Bar Position Changes With Power
Added
Engine Torque and Gyroscopic Forces
- Many pilots talk of engine torque causing the "right wing to dip on
takeoff", but this explanation does not stand up under close
examination. A discussion of what rotational forces and moments
are caused by the addition of power, and a possible explanation of the
'right wing dip" phenomenom: PowerForces.php
FLPHG Discussion Archives
Download FLPHG
Archive - Now
you can download and search the entire Yahoo FLPHG Discussion List.
Very useful information in over 32,000 posts over 13 years - EASILY
SEARCHABLE in the downloaded form: Archive
Download
Modifications and Maintenance
Glider Rack - When I got a newer vehicle, I discovered that the
front end was all plastic, nothing to attach a glider rack to. Here was the solution
I finally came up with: Glider Rack.
Video Camera Mount - I have played with mounting cameras on the wing-tip now and then, but
never found a suitable arrangement until recently, when I used one of my earlier
Video Cam Mounts with a
New HD Helmet Cam
Red
Head Conversion - The Red Head is a new cylinder head developed by Hidden Mountain
and claims to offer a significant increase in performance. There is
some impressive data to prove it: http://www.hiddenmt.com/
In 2008 Distribution of the Red Head was taken over by Stephen Wolf (
)
of Tailwind Technologies. I took delivery of one of Stephan's first units -
here are the details of the Red Head Installation
Electric Start Conversion - Photos and text about converting
the Mosquito NRG to Electric Start
.
If you've got the money you will like the change!
Clutch Disassembly - A photo series showing the parts and
dis-assembly
of the Radne centrifugal clutch.
Electric Starter
Disassembly - a photo series showing the parts and
disassembly of the Radne electric starter.
Walbro WG
Disassembly - a photo series with diagrams and explanations,
showing disassembly of the Walbro WG Carb
Gerry Farell - Explorer Modifications - Gerry has been
active in trying many modifications on his Explorer harness. Most
of them involve the Radne engine, so they should apply to most flphg
units: http://webspace.webring.com/people/bf/flphg/Explorer_Modifications.html
There are some good detail photos showing carb setup and fuel-line
modifications. He has recently been working to improve the
idling capabilities of the Radne engine: http://webspace.webring.com/people/bf/flphg/idle_adaptation.html
Large (225) Falcon Glider Modification - Marked up Wills Wing Falcon drawing showing modification notes:
Falcon 225 details drawing
Dual Tank Setup - A second fuel tank is a Mosquito option (presumably the same general method could be used for other makes too). The vented gas
cap on the single tank is replaced with a different cap that has a hose attached, with the same sort of quick disconnect used on the harness. This attaches to
the fitting on the second tank. As fuel is drawn out of the first tank, the resulting vacuum pulls fuel out of the second tank, until it is empty. This shows the setup, as well as a mistake to avoid - forgetting to open the vent on the second tank: Flat Tanks. The red arrow points
to the plugged vent line. Over half the fuel from each tank had been burned, and the engine was still running.
Platform Launching
- Here's another way of launching if you have bad knees or only rough
fields available. It's a modification of the ATOL type platform
tow launch, except you don't need a long field or winch, or winch
operator: Platform Launching
Wind Drifter Testing Laboratory - It's not fancy, but it was
easy to rig up. I plan on using it for comparing different props and
gearing.
A 7 foot long piece of PVC pipe transfers the thrust from the bottom of
the harness boot to the Thrust Measurement Device (the fact that it
looks
just like a bathroom scale is purely coincidental :) WD
Testing Lab
Keel Attachment Piece - Most people just use a tubing sleeve,
(either
inside or outside) of the keel to make the keel end removable. But if
you have
just gotten a new metal lathe/mill set, like I had, then you might get
carried
away with something fancier: KeelAttach.jpg
This
started out as a solid bar of aluminum, machined to a tube. The pop-up
button
started life as a brass pipe plug. The slot machined in one end is to
allow the
bracket to be inserted into the keel past a bolt that attaches cables.
A pop-rivet
attached the bracket to the keel extension.
Technical Tips - This document contains a collection of
useful tips
and information compiled by Ben Rembalski and posted in the Yahoo
Groups FLPHG
List Files section: TechnicalTips.pdf (160
kB) Ben updates it from time to time, so you may wish to check the
URL at the beginning of the document
to see if there are newer versions available.
Technical Tips2 - This site contains a collection of useful technical
tips for the Mosquito harness and Radne engine. NOTE: this
site appears to have been taken down. The URL I have is
http://www.woodleydowns.demon.co.uk/TechnicalIssues.htm - if anyone
knows where it has been moved to, if it has, please let me know and
I'll update the link.
FLPHG Manuals
These are what I have so far. If you have a manual you would care
to contribute, please contact me (see bottom of page)
Mosquito
A10 (Older Model) - Thanks to Garry Lee for this manual
scan. MosquitoA10Manual.pdf
(1.1 MB)
Mosquito NRG Manual - this
came with my NRG in 2001. It says there would be a new manual in
a short time, but I have not seen it if a new one exists: NRGManual.pdf
(3.5 MB)
DoodleBug Owner's Manual -
DBManual.pdf (10 MB)
Explorer Manual - thanks to
Gerry for this one: ExplorerManual.pdf
(6.0 MB)
Raven Owner's Manual -
RavenOwnersManual.pdf (100 KB)
NRG Spare Parts List - This
is also available directly from the Swedish Aerosport website: NRGSparePartList.pdf (3.3 MB)
Radne Engine Resources
Radne Engine Manual - A complete scan of the Radne
Manual in Adobe pdf format. It is approximately 2 MB in
size.
If you do not already have it installed you will need the Adobe
Acrobat Reader to view the file. The engine diagram in this
manual
is for the pull-start model. Here is the Electric
Start Engine Diagram
Radne Factory - Radne produces lightweight 2-cycle engines.
The
120cc model is currently used by all of the power harness
manufacturers.
They have a nice online store & catalog:
http://www.radne.se/Store/
Spark Plug Cross Reference - Check out this chart to find a
local replacement for your Radne spark plug: http://www.nology.com/chart.html
The NRG uses the Nippon-Denso #W22MP-U
2-Cycle Engine Animation - This is an excellent animation
and description of how a 2-cycle engine works, including the role
of
the expansion chamber in the exhaust. Note that the animation
shows
a Reed Valve between the carb and crankcase. The design of the
Radne
is slightly different in that it uses a "piston ported" design which
does
not incorporate a Reed Valve.
Radne Power Curve - These KW vs RPM power curves were
supplied
by Radne for the 120 Aero engine. You have a choice of either the
original Microsoft Excel Spreadsheet
or printed in an Adobe pdf format file.
(Note: 1 KW=1.341 HP; 10.21 KW=13.7 HP) Here is another version of the
plot which shows Power and Torque in
both
metric and English units.
Fuel Information - The EAA (Experimental Aircraft
Association)
has extensive information regarding the differences between automotive
and aviation fuel, and considerations for their use in aircraft: http://www.eaa.org/education/fuel/index.html
Walbro Carburetors
This is a collection of Walbro carb information from a variety of
sources. The Walbro WG6/8 (Radne part # 32048) is standard on the
Radne 120 Aero engine used by the majority of flphg units.
Walbro WG
Disassembly - a photo series with diagrams and explanations,
showing disassembly of the Walbro WG Carb
Walbro Metering Lever Height Gage - The official Walbro gage
for setting metering lever height. You can print it an cut it
out, or simply use the dimensions shown. To print it, be sure
"page scaling" is turned off in Adobe Acrobat reader WalbroGage.pdf
Walbro Service Manual - Disphragm
Carburetors - Thanks to Gerry Farell for this
contribution. This large download (5.8 MB) is also the most
comprehensive, with 33 pages of useful information: WalbroServiceManual.pdf
Walbro WG Carburetor - Here are diagrams and parts lists of
the
Walbro WG carb obtained from different sources:
This image from Greg Dewenter:
1. WalbroWGListFig1.zip
received from Riaan Olivier of Sperwill ( http://sperwill.com
) - these are scanned from a Walbro manual
2. WalbroWGListFig2.zip which
were originally copied from a Spare
Parts pdf document found on a UK Power Tool website: ( http://www.partner-uk.com/
- the link to the Spare parts document no longer works, but is provided
for reference. The figures are in the zip file, however.
The Power Tool Website link still works) The numbers in the list and
figure are different from the Walbro
numbers,
but can apparently be used to order parts from this dealer. The
schematic
and list figures are only useful when used in the proper pairing, which
is why they've been separated into two separate Zip files.
Wallbro Troubleshooting Chart
- walbro_chart.jpg
Walbro WB Carburetor - Thanks to Riann Olivier ( riaano@sperwill.com
) of http://www.sperwill.com
for providing this copy of the WBmanual.pdf
(800kb) Riann also provided this photo for
identifying
the difference between the older and newer WB/WG diaphrams: WB_MeteringDiaphram.jpg The older
style diaphragm has a button which allows easy bleeding of air from the
fuel lines, the new one apparently does not.
Calculators
Here are a variety of useful calculators and conversions:
Units Conversion - a very
handy (and free!) utility to convert between almost any sets of
units. It sits on my desktop and is used quite often: http://www.joshmadison.com/software/convert/
Density Altitude
- "Density Altitude" is a single number
which
effectively combines the effects of true altitude, temperature,
humidity
and barometric pressure. As density altitude increases stall
speed
becomes higher, engine power is reduced, and more power is required to
maintain flight. Below are a calculator for determining Density
Altitude
and a "Koch Chart" for estimating the resulting decrease in
performance.
Density Altitude Calculator: This calculator is referenced to
"standard" sea level conditions which means it will show 100% stall
speed
at 0 MSL altitude, 59 degrees F, 29.921 in HG Baro Pressure and 0%
Relative
Humidity.
http://wahiduddin.net/calc/calc_da_rh.htm
This site also discusses the equations used for these and other
calculations.
Koch Chart: This chart uses the location temperature and
"pressure
altitude" (which does not include the affects of humidity but does
include
barometric pressure). By drawing a line between these two values
the resulting decrease in climb rate (as compared to "Standard"
conditions)
can be found: Koch Chart
Prop Calculators and Information: Prop Performance
Calculator: http://www.gylesaero.com/_frames/f_propcalc.shtml
; How to measure pitch on your prop: http://www.mh-aerotools.de/airfoils/propgeo5.htm
; Powered paraglider site with information about repairing wooden and
composite props. It is up to you to decide whether you consider
this a safe thing to do: http://www.olympicppg.com/
More Calculators: More useful calculators can be found here:
http://www.csgnetwork.com/relhumhpcalc.html
Flying Basics and Wing Performance
See How It Flies - An excellent on-line book about all
aspects of flight physics and techniques. http://www.av8n.com/how/
Ground Effect: Here is some good technical info on
what "ground effect" is and how it works: http://www.se-technology.com/wig/html/main.php?open=aero
Animated Polar Plots - This page has some outstanding
illustrations and explanations of the aircraft "polar plot". It
is geared towards light aircraft, but the principles are the
same. Very good animations actually showing the differences of
flying at different speeds in different conditions: http://www.5c1.net/Glider%20Performance%20Airspeeds.htm
Weather Stuff - Weather is a very basic part of soaring flight, and even when it is not a flying day, learning about soaring
conditions has given me an appreciation for all sorts of weather. This is a collection of observations I have found
interesting: Weather Stuff
Flight and Engine Instrumentation and Accessories
Tiny Tach - A tachometer is
very useful, especially before take off, when you can't decide whether
or not the engine is delivering full power. A very popular model
in the flphg community is the Tiny Tach: http://www.tinytach.com/tinytach/index.php
Note that the "original" only updates every 2 seconds, while the
new "commercial" model is every 1/2 second. If the commercial
model had been available when I bought mine I would have gotten it
instead. The standard 6 foot cable is a bit short, be sure to add
a couple of extra feet when you order.
Flight Computers
Quest - flight
logging, engine info and more: http://www.activeflightsystems.com/
Brauniger IQ Motor -
flight logging, engine info: http://www.brauniger.com/info/english/products/iqseries/motor.html
Jooser Flight Data Measurement
- also a solar battery charger: http://www.aerodat.co.uk/
Fuel Gage
An electronic fuel gage for checking the level in your tank.
Particularly useful for those setups where you cannot see the tank, as
with the Doodlebug and others that have the tank inside of the
harness: http://www.microfuelgauge.co.uk
Air Band Radios - Airband radios are useful if you are flying
from or near an airport. There are a number of small hand-held
air
band radios available now. ICOM's
IC-A4 Sport model can be had for under $200 USD. Be warned
however,
that standard Ham radio type microphones will not work with the
air band radios. It took me several months of frustration to
finally
learn the solution to this. Aerial Pursuits (Australia) was able
to describe the problem as being one of a different
standard (based on old carbon microphones). All that is
needed
is to fix the problem is a small pre-amplifier which they also sell: http://members.ozemail.com.au/~aerial/comms/pttccts.htm
Once you have the microphone wired, there is still the
antenna to consider. Air band radios are AM band, which means
they don't have the normal noise suppression of FM (ham radio)
bands. That is, the unshielded Radne ignition is very
audible. Here is a useful article about antenna connection and
placement: BMAA
Article on Radio Antennas
Battery Information -
With the electric start, radios, etc., it is likely you will have
battery issues to work out at some point. Here is a handy
resource: http://www.powerstream.com/BatteryFAQ.html
(updated January 4, 2013)
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