mnowell129

Here's the first drawing for the G3PO.
I will post more details as I get them.
I will try to work up a full parts list as well.
The frame is 3/8" pine, 1/4 balsa, 1/4 glass tube and
some 1/8 carbon tube. I use upholstery thread or
kevlar to wrap the tube to the 1/4 ply landing gear mount.
The Landing gear mount is beveled so the gear is roughly
straight down as shown.
The bottoms of the mast and other front piece are groved by
wrapping 60 grit sandpaper around the glass tube and sanding.
The parts are CA's together heavily, the tube is CA' in the groove.
I glued the wood parts first then groved the hole bottom.
Note that the tailboom angle is downward to provide some
blade clearance.
I'll put up the bits regarding the wire axles, tail wheel, fin mounting
as I get them done. I'll make detailed photos also..

By the time you read this the videos of today will be at
[link]http://www.mickeynowell.com[/link]
Then click "HobbyWorld"

This drawing is to scale.

Ooops, upload didn't work. I'll try something else.

mnowell129

Maybe this is the GIF file.

mnowell129

Ok, one more time, this time as a jpg.

mnowell129

Ok so posting drawings is a pain in the %(#&*(*@#& here.
I will put the drawings on my website and inform you of updates here....

rcflyerfl

My Feedback: (1)

Hi Mickey,
I printed out your drawing and it did not print to well.
Could you send me an e-mail copy and I will see how it looks then.
I couldn't read any of the printing. It printed on the 8-1/2 top of my paper..
Did Fly my Simple "G" 3 times today. along with a P-47, GWS Slow Flyer, and 3D Foamy.
The drawing on the diagram came out good.. Thrust line, etc.
Keep the good news coming.

Jim

mnowell129

Ok, so now I have a picture and the higher resolution .jpg on the website.
I downloaded my own drawing to look at it and it seems readable.
Let me know if I need to do something else.....
Three more flights in the street this afternoon.
BTW the ground handling on this model is excellent. I can
spin the rotors, race downwind to get some rotor speed,
turn around in the street and make a nice takeoff.
This model appears to be able to takeoff and fly at
basically the same pitch trim. Full throttle is never used.
I've discovered possibly every bad way to take off poorly
and how badly it can fly with the CG WAY too far aft. So
maybe if someone builds one I can help diagnose it remote
control.

Hey Jim, now I'll get the 400 grit sandpaper out...
First thing I'm going to try is a different power plant
that is hopefully lighter and only two cells.

mick

PS
There seem to be very few responses to my posts...
Is it because:
A) You all think I'm nuts and are laughing at my ramblings
B) My stuff is so off the wall you are shaking your heads in shame
C) You hope that if you don't encourage me I'll go away
D) You are certain my neighbors are going to have me arrested
and you want to make sure they can't connect you to me in any way....

Really, its a lot of work to convert/upload videos and make the drawings.
I'd appreciate a quick "right on" or "shut up" cause there
is no reason for me to keep feeding the web if I'm just talking to myself...

rcflyerfl

My Feedback: (1)

Hi Mickey,
I downloaded the file and printed it out better.
I think that alot of people look and are taking notes and hope they can build one someday..Some of the stuff is over there heads but with the drawing it should explain everything.
Keep the stuff coming.. WE can view the movies from your web site.

Hopefully I can cut the pieces soon while I am waiting for the head parts.

Jim

mnowell129

Thanks for the feedback Jim.
I'll stay with it.
BTW I don't mind answering what may
seem to be stupid questions. I was a schoolteacher
for 11 years, as it was there it is here, "There are
no stupid questions".

Motor/Flight test update.
I just flew the G3PO with an E-FLITE
370 brushless (5400 Kv) electric motor.($48)
This is equivalent to the himaxx 2015-5400...
GWS EPS 350C gearbox, D ratio ( clearly this
gearbox I use alot) with and APC 12x6 SF prop.
TWO cell 1050 lithium.($33, from parkflyermotors.com
, apogee 1050 2s1p) same old phoenix 10 speed control.
This setup is much cheaper than the razor as the
motor is about half the $ and the battery is about
2/3 the $.
Yes is was 9:30 at night. I basically made takeoffs
down the street under the streelight and flew little
short runs. I got takeoff at about 80% throttle so
this setup won't be quite as agressive a climb as the
three cell but may be much better at slow flight.
Will let you know when I can fly in the daylight and
get up and fly around. Ground handling and takeoff
runs still excellent. Last "flight" I had a 5-8 knot headwind
and got 10-15 seconds of near hover under the street light.
Note: This model still has 2 MPI MX30 servos for pitch and roll...
no high torque, metal gears required.
mick
I wonder if the sony handycam works under the streetlight?....

Cvans

I can assure you that you are not waisting our time. I am watching your every move. I have been at this hobby for decades but have no Gyro experience to base any replies on. You might say that I am silently amazed. Keep up the good work and thanks for letting us watch over your shoulder.
Chris

mnowell129

Thanks for the feedback Chris.

I flew G3PO this morning with the eflite brushless
setup described in the previous post.
10-15 knot headwind but I managed to takeoff twice
and fly in the hood. Second takeoff roll
was only about 30', it came off so fast it
took me by surprise. Like I expected it takes
more throttle to fly compared to the razor setup.
Seems to fly just fine at about 80% throttle, about
like I expected. Fairly agressive climbout so it's very
flyable in this configuration. The excellent ground handling
is a delight with this model and makes the takeoffs effortless.
The astro flight watt meter says this is 75 watts at full tilt,
about 60-65 at the throttle setting I was using heading upwind
up high. It seemed to be able to fly level down low at closer
to 60%, so the math seems to check out.
More reports when I get some calm weather.

Next steps are to try some twisted blades, then some
1.5 inch and 2 inch aerobalsa blades. I suspect that the
twist is going to have more effect than the airfoil...we'll see.

Anyone willing to send me an outrunner himaxx to try?

mnowell129

Power update.
THe eflite motor on 2 cells will fly around level but is not impressive.
I switched back to three cells and a 10x4.7APC SF.
This combination is fine.
Nice takeoffs in 20-30 feet with a little headwind.
Cruise around at 5/8 throttle, nice rudders turns in the street.
So this would be a reccommended setup:
eflite 370,(5400 rpm/volt) or himaxx 2015-5400
GWS EPS350C-D (6.6:1) gearbox.
Phoenix 10,
apogee three cell 830 or 1050.
APC 10x4.7SF prop.


I will continue to search for a two cell setup that will
work.....
I feel like I have an operational aircraft at this point.
Taxing around, accelerate, takeoff, make turns, slow fly
in the hood, nice landings at near zero groundspeed, then
taxi back to the driveway.
May get around to trying loops and rolls but this really isn't
my goal, besides the helicopters fly much better inverted.
The long term goal is to make one of these fly much slower
at much lower power settings for indoor work.

mnowell129

Tried to fly the G3PO with 2" aerobalsa blades in stock configuration.
Was able to fly but not very well, resulting in a minor crash that only
cost a propellor. Returned to my stock blade. Will try to modify them
to a workable configuration.
My first attempt will be to reduce the chord to 1-3/4 and add the
tip weight found necessary on the working blades.
My current theory is that these blades are too low an aspect ratio
and the rotor RPM never came up to the speed I needed. It flew
at low speed but the control was poor and the rotor RPM varied
wildly.
The rotor lift equation L = (1/6)*(airdensity)*(area)*(tipvelocity)*(tipvelocity)
favors rpm over area.
These blades were 114% the are of the otherones, but if the rpm went down
by 6% (0.94 of the original tip velocity) the net lift is the same (.94*.94 * 1.14) = 1.00.
I think this is a net loss because the RPM was way lower than than 94% of
the original set. This leads me to experiement with the 1.5 inch blades as well.
more later

mnowell129

I built another G3PO tonight after dinner and made more streetlight runs.
I built this one from my own plans to make sure everything is ok on the plans.
I have updated the drawings slightly to make the landing gear mount more
robust. Will post new diagrams soon. The new drawings print out on 8.5 x 11 paper
full size so you can use them for templates for the main body, fin, rudder and landing
gear mounting plate.
Jim is sending me an AXI outrunner to try that I will report on ASAP.
Only critical test item left is the aerobalsa 1.5" blades. I have them prepped for
covering and only need install blade reinforcements and drill holes. Perhaps tomorrow
evening.
I have the construction down to 6 wood parts, 3 of which are just pieces of 3/8 square stock.
1 of which is the 1/4 balsa filler, then the LG mount and the fin mount, that and the fiberglass
tube and CF landing gear are the only chassis parts.
Here's the detail drawing on the fin/rudder/tail wheel assembly..

mnowell129

Here's the main chassis, LG detail.

mnowell129

Great news (I get excited easy with models...)!
I flew with the 1.5" aerobalsa blades with great results.
Went to 15", 3" of solder leading edge weight, laquer prep,
monokote trim sheet covering. 1/32" ply reinforcements.
Don't have to make blades anymore....
when will they be back in stock at aerobalsa?

mnowell129

Ok, here's the lowdown on G3PO-B.
I built the current one from my own plans that are posted.
The easy thing to do is cut out the 1/4 balsa piece then
shape and glue the 3/8 stock around it.
I made the tailboom 24-1/4" inches to give myself a little more
blade clearance and allow for the part sticking through the LG mount
hole. The landing gear mount is about right but needs
a little more beef below the hole, so I'll correct the drawings soon.
However if you are building one add some thickness below the hole.
I glued the servos on with zap, the ones on the mast are also zip tied.
Tail is built as shown on the diagram.
The ground handling is still excellent, I can drive around in the street at
high speed without tipping, so I wouldn't mess with the overall attitude,track and wheel
locations.
Rudder servo is glued to the body upside at the bottom of the mast.
I used dacron 1/2 control line for pull pull control.
Weight about 13 ounces with the razor and 3 cells.
It needs a touch more downthrust so if you are building, build in say 8-10 degrees
or leave it where you can modify it. It will vary with power available, my razor setup
has lots of thrust.
Aerobalsa 1.5" blades cut to 15", weighted and covered with trim monokote.
Cruises around nicely at half throttle on the razor setup.
I can haul this little model around in about a 50 circle at low altitude, so the control
is excellent. Will try loops with this model when I get a chance. Probably should go
make a living sometime now...

I think there is enough info to build one with the following items included ( I will post these as fast as I can).
1) Where, how and how much lead to put in the blades.
2) How to finish and cover the blades (overlap on the bottom TE, helicopter style)
3) How the blade reinforcements are put on (NO CARBON FIBER on the blades, it ruins the airfoil).
4) The dimensions of the blade straps.
5) The Detail on how to make the antirotation link ( you can be creative here if you like
it just needs to keep the swashplate from turning and let it pitch and roll and not hit any links,
look at the Dragonfly manual to see how they do it at balspr.com). I will put photos of mine up.
6) The trim settings on the swashplate.
7) The static incidence of the rotor blades.
8) How to reinforce the GWS head plate when it wears out.
9) A diagnostic list of what's wrong if yours flies funny. (There are some very
funny behaviors if you get the blade bolt tension way too loose or way to tight).

I sincerely hope someone else can make one of these fly...

Note: You are on your own if you fly without weighting the blades properly. This GWS head is flexible
and if the blades are tail heavy you can fly but you will have your hands full. Let me be perfectly clear on
what that means. I have been flying R/C for 28 years, I started flying helicopters in 1981. I can hover
my airplanes and do slow rolls at 5 foot altitude, i can fly a helicopter inverted. So let this be the gauge
of what it means when I say it was a real handful to me. I don't want to incur somebody's wrath or a lawsuit
because with weighted blades it's still more challenging to fly than a 4 channel airplane but is flyable
by the average pilot, unweighted its probably going to hit something hard (mine did).

A firm conclusion, longer skinnier blades are much better than shorter fat ones. This has been
stated before on the mighty fine autogyro.com website, but I made a serious confirmation for myself.
I think you could even go to 16" blades on mine if there was rudder clearance.
I hope I can prove to myself that finish quality is as important as airfoil, by making my own
1.5" blades with homemade airfoil section. I believe finish quality on the blades is paramount to good performance.

I continue to appreciate the feedback. I hope I can help others build some of these.
Is someone going to try one with gas? I don't have a place to fly gas anymore but I think
this would be just dandy with a norvel 0.061...

mnowell129

P.S.
The landing gear will break off if you fly into your neighbors mailbox...

gyronuts

Hi,
I note that you use GWS dragonfly head bits. Do you think Picollo Fun head bits would work. The reason I ask is that it is cheaper in the UK to buy a basic Fun than to buy the head bits seperately. A quick reply would be appreciated as I type this there is one even cheaper on Ebay. Many thanks. Bill
Also copied on ezone.

mnowell129

I think any fixed pitch micro electric heli head would work, or even
a collective pitch one with the collective locked down.
I chose dragonfly because it was the cheapest parts available here,
and I wanted other people to build it.
By all means try any other head.....
mickey

gyronuts

Hi, Thanks for that. I shall scour ebay for some suitable bits. Have been dabbling with gyros of and on for 21 years. Yours looks so simple and flies great. Mine go ok but I crash due to impatience or orientation problems!! My 3d models and bigger fly ok though. thanks. Bill
Some of my gyros are in the gallery.

rcflyerfl

My Feedback: (1)

Hi Mickey and other Gyronuts,
Just to let you know that I am working on the G3PO a little bit.. Waiting on some more parts and working on the PT Gyro at the same time, along with a Giant Size P51 for a client.
Keep you posted.

Jim

mnowell129

Looks good jim. Awaiting the axi.
Broke down and got the himax outrunner
2808-1180. It flies with 3 cells and a 9x3.8 prop.
Opens the door for a pusher....

mnowell129

Got the axi in the mail today, I think I have a motor mount worked out.
May be able to try it in the morning.....

mnowell129

Jim,
Got the axi mounted, flew it last night under the streetlight and again
this morning under the streetlight.
Looks like it might be a keeper.
Will let you know more after I fly in the daylight.
Will also photo graph the motor mounting techinque.

mickey

mnowell129

Flew G3PO in the daylight with the axi.
It flies very nicely.
A flight note, turns take a healthy dose of
up elevator, with right turns taking more than left.
It has a lot of roll/pitch control so its wise to take it up
high and experiment. I will post video on the website
sometime today of the low speed flying with the
axi powered, aerobalsa blade model.
Note that I added a tail boom brace, this pushrod tube
was more flexy than the other one and needed it.
The symptoms of a flexy tail boom are really bouncy
handling on the ground and it tries to lift off too
early.
I'm going to add this brace to the plans, because it
weighs next to nothing and really helps.
Its a bamboo skewer and a piece of 1/4 balsa.
The pointy end of the skewer is wrapped with thread
and CA'd to the tail boom.
ALSO, the axi motor mount let me move the CG forward
some, It now hangs with the mast straight down + 2 or 3 degrees,
i.e. the CG is slightly ahead of the mast. This made a nice improvement
as now you can just feed power in and it will ROG without any help.
It reduced the pitch power somewhat so I may move it back slightly.
My rule of thumb is now mast straight down or a tiny bit more nose heavy
than straight down.
Here's the axi motor mount I whipped out and a detail picture of the head
showing the shaft length, anti-rotation link, and trim setting of the swashplate from
the side. The side to side swashplate setting is roughly level. This was the trim
position during the morning video.
mickey