Rube Goldberg

Had the maiden flight of my Gee Bee 120 this afternoon. Powered by an OS FS120 Surpass II with pump and a Master Airscrew 18X6 prop. Take off was uneventful, flight was fine but controls seemed very slow......nothing like was expected with the short coupling of the wing and stabilizer. Balanced at 80mm from the leading edge instead of the 105mm as per the plans. Needed a bit of down trim, left and right was fine.
Didn't realize my landing approach was off line from the paved runway until I had committed on final......flared and slow three point landing in the short grass...right at the spot where the ^&*#&%@ club gopher had made his underground trail across the field leaving the sod a bit raised up. Plane cart wheeled and wound up with a wounded cowling and one wounded wheel pant. Other than that, it'll fly again, probably next weekend.

Any plans to restock this ARF?

opjose

Could you post a pic of the cowling area.

I'd like to see how you finished the dummy engine, how you mounted the engine, etc. and how it all fits in.

I've been wanting to purchase one of these but have been taken aback by the pictures on the web site which makes the plane look rather cheap, though I understand it's a good plane.

Rube Goldberg

[:@]F***ING dial up!! I just lost a %&^@%^ 45 minute detail of how I built the cowling and connection timed out!![:@][:@]

I'll take a few more photos of the cowling assembly and outline it all in the next few days....the plane is a pretty good quality plane. IF I drove this one into the ground, I'd probably buy another...that is IF you can FIND one! Is Nitro/Raidentech going to offer the Gee Bee 120 again in the future?

opjose

Also do you know of the Robart Gee Bee struts fit this plane?

Thanks.

Kmot

My Feedback: (24)

Hey Rube, I feel your pain! I even have cable internet and sometimes RCU times out on me. I think it is RCU's software that does it. It has become so problematic that I have been forced to learn a new technique when posting here. Before I hit the "OK" button, I right click and copy my entire message. That way if it gets lost in a timeout, I have it all saved ready to re-post again.

*This is the second try. It timed out on me!!!

Rube Goldberg

Don't know about the fitment of the Robostruts. The ARF as supplied includes a pair of long springs, one for each gear leg that goes from about 2/3 down the leg to a tie down point towards the leading edge. It all fits in the wheel pant and is unseen. I modified the tie down point and added a plywood plate to the bottom of the wing for the eyehook to screw into as the tie down point. In effect, when the plane is sitting, the weight of the plane itself causes the landing gear to move forward tensioning the springs. The supplied manual included an "expert tip" to leave most of the travel motion of the landing gear (the opening for the wheel in the wheel pant) towards the front.
Before the maiden flight, in fact the morning of the maiden flight, I took a Dremel tool and lengthened the wheel opening about 1/2-3/4 inch behind the wheels. Looking back now, I probably should have done it to the front of the pants as well......

So now my thoughts are to just fly the thing a bit without the wheel pants to practice the landings. But then I start thinking about how it tracked so smoothly in flight.....like it was on rails......and how slow it was to get it to turn, and I wonder just how much those wheel pants act as vertical stabilizers to enhance the vertical fin/rudder that are big time obstructed by the large diameter of the fuselage itself. The CG without the pants remained the same----and a CG of 80mm back from the leading edge of the wing was a number I came up with seeing as how the Great Planes version states, rather DEMANDS you place the CG at 70mm, while the Fly-Models ARF (the one you get) states the CG be at 105mm from the leading edge of the wing--which is on the main spar---as I have searched the RCU forum for this and seems 105 is waaaaayyy tail heavy. The maiden flight required quite a bit of down elevator trim at full to half throttle, and it would dive pretty hard at less than half throttle. The old OS 120 Surpass II with the pump pulled the beast around really well at half throttle.

I'll take some pics of the cowl etc. and detail that in another message.

opjose

I'd love to see more pictures.

Yours looks REALLY good.

By comparison the web site photos look pretty bad.

Rube Goldberg

Here's a few more pictures from the day of the maiden flight. Note one of them has my little Ultimate bipe in the background. I threw in a photo of my Travel Air Mystery Ship that I acquired a few years ago at a swap meet for $50. It's a beater that I'll someday restore. Flys well though with an OS 91 four stroke.

I was able to conceal a lot of things under the big cowling. The switch for the radio is on the side of the fuselage behind the edge of the cowling, as well as a remote glow plug fixture. I drilled a pair of holes in one of the cowling "tabs" that bolt the cowling to the fuselage (4 of them) and routed fuel tubing through the holes....one for the fuel fill and the other for the vent. The other lower "tab" was drilled with a small hole where I routed a cable to the needle valve and at the other end of the cable I drilled out an aluminum fuel dot and crimped it to the cable as a neat knob to turn the cable/high speed needle valve. You can see that in one of the photos as I had forgot to merely push it forward to conceal it.

Special Thanks to Alex at AK-Models.com for the Gee Bees' pilot---he's an Iowa boy you know![sm=punching.gif]

opjose

More pics! More Pics! More Pics!

I'd REALLY love to see a closeup of the cowl area with and without the cowl in place.

I'd like an idea of what went into your faux engine.

Rube Goldberg

I'll see what I can do about some detailed photos of the cowling. It's all put back together now, and the way it has to be installed, although neat, isn't exactly "user friendly" as the 4 bolts that attach the cowl are accessed from inside the fuselage on the rear of the firewall-----yep, totally opposite of what you'd normally do. This allowed me leave the "faux" engine intact without drilling access holes to insert a screwdriver/balldriver from the front. The blind nuts that hold the cowling bolts are on the front side of the 4 wood "tabs" that are on the cowling ring inside the cowl.
The "faux" engine arrives as a piece of white plastic. Basically all I did was drill it for the 3/16" diameter aluminum pushrod tubes, cut the tubes from aluminum stock and fit them while holding the faux engine flat on a table. Made sure it all fit together and then removed the tubes. Sprayed the entire "faux" engine with Top Flite Lustrekote Dove Grey, front and back. Then masked off the center of the faux engine and shot the rest of the front with Flat Black Lustrekote. Built a plywood former which is just a circle with the center cut out to fit the outer perimeter of the faux engines cylinders and glued the faux engine to it---of course this was before I painted everything.
First impression when it was still white with the pushrod tubes installed was "oh no! It looks like a crummy Autozone hubcap!"

The canopy was hand painted on the inside with Testors paint. I think the color was Sprint White, and it is an acrylic paint or whatever the RC car gang uses on the lexan bodies. Trimming the canopy to fit took a bit of time and a lot of patience. Made a headrest out of light ply covered with black monokote trim sticky back. Basically trace the outline of a small wheel on the plywood, drill a very small hole about in the center big enough to fit your dremel tools cut of wheel adapter, fasten the ply circle to the dremel tool and spin it up on a piece of sandpaper. NOTE: it gets smaller real quick!

opjose

It looks very nice.

So much so, that it's almost hard to believe it's the same ARF that NP sells if you go by the pictures of the disassembled plane.

That plastic engine looks horrible in the photo.

Rube Goldberg

Thanks for the compliments. STILL no word on if Raidentech and/or Nitroplanes is going to restock the Gee Bee 120?? Otherwise, good luck finding one.......at a price less than the Great Planes version......which you CAN get spare parts for. Wink wink, nudge nudge.

Rube Goldberg

Well, after 2 flights with the Gee Bee 120, here is my review:

Take offs no problem. Gets airborn in no time with an OS 120 Surpass III pumper.
Flys like a dream, even at about 60% power. Looks GREAT in the air.
Landings SUCK, that is IF you can land it!

I've been flying models now for 32 years, and today was the second flight of the Gee Bee 120. Entered the pattern on a down wind leg at about 60% power, made left turn on to base and after another left on to final pulled back to about 35% power for a long final. Started sinking really fast.......get on the throttle and about 50 feet short of the threshold and 15 foot above ground level the left wing did the dreaded "dip" and then began flying again into a right roll and it was game over. I snapped it in on landing. I can attest that the Gee Bee 120 goes from flight to no flight in less than a moments notice.....and it wasn't slow at all.

Impact was the side of the cowl and the right wing tip. The wing broke in half. I kid you not...the ^#^$& thing broke the dihedral brace/wing joiner and a bit of one of the wing ribs at the joint. No other damage to the wing. Fuselage is kind of flimsy, but possibly rebuildable.

Boy, all that time I had building the thing and I got 2 flights out of it. Such is the world of RC![&:]

opjose

Sounds much like the behaviour of the GeeBee as modeled in G3 when you put the heavier O.S. 1.20 engine in the model.

Ugh...

nitrostaff1

Ok i'll carry some geebee in our next shipments. We have a bunch of them but it took us forever to sell them so.....

I'll have some on our next shipment. Thanks

John
Nitro Planes

Rube Goldberg

I don't know that I would recommend the Gee Bee 120 to anyone.....not that it's a bad airplane, but rather a very difficult airplane to land due to the weight and high wing loading. But thats the nature of the beast. Perhaps If I had either cut out all the areas around the cylinders of the "faux" engine in the cowling, or done without the "faux" engine altogether the drag may have been significantly lowered and the plane wouldn't start coming down so fast when backing off the power on final approach. 'Course it wouldn't look so cool without that "faux" radial and pushrod tubes......I can tell you for a fact that a Gee Bee will fly fine without the wheel pants, as they were not in place for the second flight after removing them after the maiden flight. I was hoping to "fine tune" the landings. So much for that idea!

Last year I decided I wanted a real "challenge" of a model airplane. The Gee Bee was challenge #2, the 46 size Long-EZ was challenge #1 and the other Rutan design being the 40 size Quickie was challenge #3.

2 out of 3 aint bad, huh?