RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Well, that explains why Doug has not given us much detail himself,,his hands are probably still shaking!
Good save, Check out everything,paying attention to the thrust lines,and try again.
Good luck!

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Hey Guys,

Ive been busy lately, And your all right, My hands are still shaking, The one thing that I did that may have hurt me was that I moved the engine out 5/8 of an Inch, I did it to achieve CG, Im not real sure of all the affects of doing this, It may have made my torque issues more noticable, I have not done anything with the Model since test flight, I have a lot of time in it and lucky that I got it back that way.[X(].

So at this time I have to rebalance and possibly shift the engine back. Any advice would be most helpful.

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

I don't believe the shift forward of the engine 5/8" to achieve CG would have a substantial affect on flight performance.
Assuming your prop/thrust centerline is close to the aircraft centerline and your engine dome is mounted such that you have the correct right thrust, and zero down thrust, you should be fine.

When I went from the DA150 to DA100, I shifted my engine out 1.75 inches from the firewall! However, I also used an unmodified cowl with the stock metal mounting tabs such that its back edge of the cowl was even with the fuselage front.

I had modified the first cowl so that its mounts positioned it to the rear for a goodly amount of overlap like the full scale bird.

btw: These Gee Bees seem to require ALOT of up trim from neutral elevator to achieve level flight. I believe the 2.5 deg. of positive wing incidence has alot to do with that, but a small CG shift will also have a PROFOUND affect on elevator trim, as I have experienced.

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Hi,

my name is Hannes, I´m 25years old and I´m vom Germany.

First I have to say "sorry" for my bad "ENGLISH" andif I don´t understand some of the postings:-)

I´m a big Gee Bee fan & I´m reading hier since a longe time. So I thought it would be time to show a few pics of my composite Gee Bee R2.

Perhaps somebody like it :-)

It´s powered by a DA 150 & JR 4421 Servos*

Here are a few pics:

http://home.arcor.de/geebeer1/rcu1.jpg

http://home.arcor.de/geebeer1/rcu2.jpg

http://home.arcor.de/geebeer1/rcu3.jpg

http://home.arcor.de/geebeer1/rcu6.jpg

http://home.arcor.de/geebeer1/rcu4.jpg

http://home.arcor.de/geebeer1/rcu5.jpg

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

VERY VERY NICE :)
How do you like its flight characteristics?
How many flights do you have on this Gee Bee?
How did you make the dummy radial engine?
What is the weight of the aircraft?
Prost!:D

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Hi,

the first flight made a good friend of mine, he "ride" one round.

Here is the link to the you tube Video of it:

www.youtube.com/watch


The dummy of the radial engine is from Modellbau Petrausch vom Germany.

There is the link:

www.petrausch-modellbau.de/smattrappen.html


I don´t know the weight of the plane, it was crashed bevor I could check it :-)

The engine stoped in a low fly by :-(

http://home.arcor.de/geebeer1/rcu7.jpg

http://home.arcor.de/geebeer1/rcu8.jpg



But in a few days I start a new one with a 3W 100ccm** :-) I hope then I´m more lucky** :-)

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

OUCH!!![:o]
I know EXACTLY what you are going through as my engine quit on flight #6 and I had to land the plane out in a very rough area. However, I did repair mine and continued to fly it until just last Sunday when I sold it after flight #34.
The Gee Bee R2 DOES NOT glide well![:-]

Thank you for the links.
Here is a link to my Gee Bee R2 flying:

http://www.youtube.com/watch?v=jemTfMES3X0

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Thanks for the link. I know this Video, I say it perhaps 100 times :-) I like it.

Your exhaust is sooooo loud! When you would fly it in germany they would take you to prison :-)

I repaird my Gee Bee and sold it @ eBay.

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Actually, most of the noise is the XOAR 'Silver Sword' 30x12 propeller.
However, I agree, the combination of prop and stock mufflers on the DA150 does indeed RIP!!!:D

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Hi Richard,

can you tell me how your Gee Bee ist exactly balanced out? I mean where ist the center of gravity? Emphasis?

I don´t know the exactly english word for it, in german it´s called "SCHWERPUNKT" :-)

Do you know what I mean?

thanks
Hannes

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Hey Hannes,
I have done extensive research on cg location and have found 2 7/8" or 73mm back from the leading edge at the root to be the best (safest) location. In the 230 flights I now have on my Gee Bee about 190 are at this location. I have also found that it is very important to have dihedral equal on both sides and I mean exactly equal!
When everything is straight this is a fun plane to fly.
Jim

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Hey Rickster
When can we get a flight report? I am engine shopping and would like to know how the Moki works out.
It is a toss-up between a DA 200 and a Moki 250.
Jim

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Hi Jim,

thanks for your answer.

What happens if the dihedral equal is not perfect? Is it importantforthe curving or to go ahead?

cu

Hannes

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

If the dihedral is not even, you will find yourself constantly trying to trim the airplane with the rudder. The tracking will be constantly changing from left to right.
In one of my earlier threads I mentioned what I found to be the best angle.
Jim

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Dirty,
You just described the flight characteristics of my first Gee Bee... constantly shifting left to right.
Some of it had to do with the right fin offset which was highly effective at high speed, and ineffective at low speed, but no amount of trimming or rudder/throttle mixing seemed to get it under control.

I often looked at my Gee Bee to see if anything was out of whack and never noticed. HOW are you verifying that dihedral is equal on both sides?

On Gee Bee #2 I have increased dihedral slightly, per designer. Just not sure how to be absolutely sure dihedral is dead nuts equal?

I have flown mine at 18% back to 22% CG. 18% seemed to be the sweet spot for me which if I remember was about 77mm.

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Ok, from 73mm to 77mm is a long distance**

În the composite manual is called 75mm**


So, what should I do? :-)

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Easy, split the difference. 75mm.

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

GO WITH 75mm.

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

NO flight report yet. I am still creeping along slowly on the Gee Bee.. I have run the motor quite a bit and am getting it lined out to where I am happy with it's habits.. I think it will fly the plane very realistically but definitely will not have the WOT speed that is seen with the 150-170cc engines.. The Moki will turn a 32X18 prop at 4100-4200 on the ground and would likely unload to around 5000ish.. I do not think the GB would handle the 18-20 pitch props very well so I will likely stay with a 32X14 , maybe even go to a Solo prop to have the adjustability to see what it likes.. With these high pitch props on a 150-170 you would have to kill the engine to land it more than likely but the Moki will idle reliably at 500-700rpm so the idle creep should not be an issue..

Rick

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Rick,
For What it's Worth... I did speak at length with Andreas Gietz about powering the Gee Bee with a Moki 250 which, btw, he thinks is a match made in heaven... and he stated that you would absolutely have to go with the 32x18 as any less pitch will not provide sufficient flying speed.

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Going off some static speed calculators using the pitch and RPM ( not at all an accurate figure but makes decent comparisons between configurations) a 10" pitch (Typical of most 150cc engines) @ 7500 rpm ( an optomistic WOT figure) comes out to 71 mph.. A 14" @ 5200 rpm comes out about 69 mph and a 18" pitch @ 89 mph.. I think if the plane would handle the torque reasonably well a 30X18 or 30X20 would be the ticket ....:D

Rick

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Tached the Moki 215 today on the test stand.. After running it for about 5 minutes I ran it WOT and it turned the Bolly 32X14 4800 rpm and idled at 700rpm.. I am very pleased with this as I have tried this prop on a 3W 170 with stock cowl mufflers and it loaded it down to 4900-5000 on the ground static..

Rick

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

News vom germany.My newGee Bee is 95% ready to fly.

Next Week I´ll check the 3W engine & then I´ll be try the first flight.

Here are some pics:

http://home.arcor.de/geebeer1/rcu10.jpg

http://home.arcor.de/geebeer1/rcu11.jpg

http://home.arcor.de/geebeer1/rcu9.jpg</p>

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

NICE PAIR!
I also like the planes, good luck with maiden flight.

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

VERY NICE;)
Are you going to check the weight on this one??
I am trying to obtain one of the dummy radials you recommended from Germany as there is nothing available in the U.S. that is the correct size.
Hope you have MANY great flights (hope to see some video)!