Lifer

My Feedback: (1)

To twist the wing properly you just about need 3 hands! I place the wing between my legs to stabilize it, twist in the washout with one hand, and use the heat gun with the other. Do both sides, each with between 1/4 to 3/8ths inch washout, and be sure to get it as equal as possible between both sides.

Over the years, every time I walk besides any full-sized aircraft, I usually sight down the trailing edge. You would be surprised just how many man-carrying aircraft use this technique.

Yes, it usually takes a lot of force to twist the wing. This is good however, as it indicates a strong structure. My landings were stable, and just about as slow as anyone could want. Best of luck.

rowdog_14

My Feedback: (5)

Ha anyone tried the wing droops like the gentleman said in post #518. I think this will work too, because it gives you more surface area and just a little bit more lift. Like he said this may help with the landings

mrcasey69

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I know that using this motor is just asking for trouble but what the heck. I am using the Robostruts. That should help.

GaGeeBees

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Why do you say that using the Saito radial is asking for trouble?

mrcasey69

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From what I've read on this forum, keeping the Gee Bee as light as possible helps with the landings. Saito 170Radial has about the same power output as a Saito 120 or 125 4 stroke but with a lot more weight. I am hoping the Robostruts will compensate for this (although the struts add weight themselves as well). Using the 170R is not ideal if keeping the weight down on this plane is an emphasis. Regardless, I love the sound of the radial and will try it anyway. I WILL do everything else I can to reduce weight (especially in the battery department). I hope to fly the plane soon. The weather is getting colder up here and may not have a chance before spring.

GaGeeBees

My Feedback: (23)

You're right to be concerned about keeping the weight down. In my experience the 1.70 falls between a 1.20 and a 1.50 in terms of power. I have one on a Pacific Aeromodels Clipped Wing Monocoupe and it's an almost perfect match for that airframe. I also had one on a Top Flite Beech Staggerwing but found it to be marginal on takeoff. Once in the air with the wheels up it was plenty, but taking off was a test of resolve. The radial weighs 21 ounces more than a Saito 1.25 but you also have to add in the weight of an exhaust ring and an onboard ignition system with battery pack. All up you're probably looking at an extra three pounds. That's a lot on a plane this size. I do agree with you about the radial sound though. Nothing like it. Here's a short video of mine running on the Monocoupe. http://www.rcuvideos.com/video/Monocoupe-Radial-wmv

YogoBlue

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Wow nice monocoupe. Very nice.. That engine is such a pain to start up huh?

GaGeeBees

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LOL yeah... exhausting! That's the thing I like about Saito multi-cylinders (both their twins and radials)... it's usually prime and one flip and they're off.

Apologies to all for the somewhat off-topic discussion. And now, back to the GP Gee Bee...

DaveSR71

Hi Guys!
Glad to see this thread still going!
Am slowly aproaching a finished engine for this over a year old GB of mine-looks good hanging on wall.

FoodStick
I have been milling weight off a couple of saw/weed eater engines for GB.
What does yours weigh with the 25cc?

Like Lifer saidwash out!!!never fly scale with out it!!!!!!!!!!!!!!!!!!!

Cross wind landing main problem with GBthe fuselage blanks the airflow to the down wind wing.

Wash out helps!
keeping nose into wind and learn to fly sideways helps(X- controls)
Slow down elevator and ailerons.
Keep it slightly nose heavy.

On my Gee Bee I added structural flying wiresnot the smartest thing on a wing not designed for compression loads but for me the wing just is not as ridged as I would like so what the heck they look scale.
All 8 wing point attachments are adjustable(2/56 threaded/clevis) and WASHOUT is set with them and then the covering re shrunk.
Currently airplane sits with washout held in place by the wires/covering tension.

WHEN( not if!) I finish this thing the wire tension will be reduced to reduce compression loads in the rib bays.
Hopefully the washout having taken a 'set' by then and will stay.probably will.

Really!! I will finish this thing!!!(and Mr Mulligan)Really![>:]

Did get to fly the P-36 most of the summer so that was fun!

Will check in again soon!

foodstick

I am afraid I don't know the weight, I can't remember what it came out at? I put alot of the radio in the back and didn't have to add any weight to balance it, just move my battery around.. It came in slow and managable.. I just wasn't used to the crosswind habits, and my wheel pants were to long, It flew nice .

rowdog_14

My Feedback: (5)

I finally decided that the saito 125 if probably going to be to light. I would have to add dead weight to the plane to get it to balance out. So I put my OS 120 back on and it balance perfect with out the radial. I now am thinking about buying a saito 150 and putting it up there, this will keep me from adding any dead weight. With the OS 120 I am a hair shy from 10 lbs. I know the saito 150 is 30 ounces but it does not say how much it is with the muffler, does anyone know how much it is with the muffler?

Lifer

My Feedback: (1)

Whatever a Super Tiger 2300 weighs with a Bisson muffler balanced mine exactly where the instruction book called. I added washout and used a 16x6 prop and it was a pleasant flight.

mrcasey69

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Rowdog 14, I just weighed the muffler on a Saito 150 I have kicking around: 2.93 o.z. with the nut for stock muffler. I can't weigh engine and muffler together. Hope this helps.

rowdog_14

My Feedback: (5)

Thanks Mrcasey69 that is great. This should put the saito 150 around the same weight of the OS 120. The saito should come out around 32.93 and the OS is 33.3 about .4 oz lighter. This will work out great more power same weight. I need to add a spinner hub to it too so this will even things out.

Does anyone know a good way to weight the planes? I have a fishing scale from wal mart that I use. You just hang it from the engine or the rear wheel. It seems to work great but I am just wanting to know if there are any decent priced digital scales out there that I can buy.

Thanks again Mrcasey69

Nickrc3

My Feedback: (6)

So,
I purchased two (NIB) GP Gee Bee R2's at a local swap meet last year and finally decided to assemble one of them. I've got one week into it and what remains is to mount the radio gear, pilot and canopy. This is definitely one of the most beautifully-fabricated ARF's I've seen in years. Instructional manual, paint and overall appearance is outstanding.
I built it exactly per plans and will use the O.S. 120-e Surpass for power, Electro-Dynamics glow driver system, JR 821 digital servos and the supplied landing gear.
Haven't balance her yet; however, I was quite careful to avoid excessive usage of epoxy, so hopefully I'll be around the 11 lb. range.

I've got extensive warbird experience; however, I'm still a little apprehensive on that first flight which I expect will take place next week during the X-mas break. Is it recommended to fly this plane off a asphalt runway, as opposed to a grass field considering the stock wire gear is used?
You guy's utilizing 'expo' into the elevator? What prop provides the best braking affect with the O.S. 120 4-CYCLE - 16" X 6"?

Heli-Rod - Do you still own and fly your version @ Markham Park.

Thanks guys,
NICK

jaka

Hi!
A 16x6 will be perfect!
Being a pylon racer at heart for more than 25years, I still find it difficult to land that damn [:@]airplane. Still, my GB is light , weighting just 5kg (5000g). With a 15cc MVVS and 15x4 APC prop it just leaps away at take off.
Differential on the ailerons seems to help slightly !

foodstick

Nick you will be surprised how easy it takes off and flies, I would think as long as your planes wheels roll good and don't contact the wheel pants you should be ok, One thing I would check is this..if you slightly pinch the bottom of your wheels upwards into the wheel pant do they easily touch the inside of the wheel pant? If so they are going to touch when you land, at least for a second...now while they are pressed up in there take your other hand and see how much they are grabbing turn the wheel as if its rolling with some pressure on it..see how much grip it has, if it seems tacky, then try this mod, wrap black electrical tape around the outside of your tire like it is tread, now compress the wheel and try turning it again, it might help..it acts like a grease to keep it from immediately putting on the brakes at that critical landing moment...

I flew mine with my wheel pants WAY to long, and it wouldn't even roll in the grass, and since inexperience with the plane a a cross wind kept me off the landing strip I did the nose over, try to avoid the to low wheel pants, and sticky wheel issues! It will be worth the work, and slightly less showy wheel pants !

Nickrc3

My Feedback: (6)

Good tips...thanks guy's.
I read the thread regarding aileron differential having a positive effect on landing; don't quite understand this as differential is generally more surface deflection up than down. How would this be beneficial on a landing approach?

NICK

Lifer

My Feedback: (1)

Up aileron reduces lift on one side, while down aileron increases lift on the oppsite side. The problem with downward aileron deflection is that it can, at low speeds, stall that side of the wing, which is not good at low speeds and low altitude!!
Differential is used on semi-symmetrical airfoils, and more-so on flat bottom airfoils. High-wing placement also calls for differential to prevent skidding into a turn that is the opposite of the intended direction. (Right aileron called for and a left turn resulting.) Fully symmetrical airfoils don't suffer from this problem, in most cases.

Twice as much up deflection as down. Use linkage set-up or electronic if running separate channels. You will be pleased with the results!

heli_Rod

Hi Nick,

I don't fly the GeeBee anymore. I gave it to my son. I don't think he has gotten brave enough to fly it yet...LOL. The GeeBee isn't hard to fly. It is surprisingly fast! I had a Saito 120 in mine. They are a little pitch sensitive, but nothing to get excited over if you are a seasoned pilot. The biggest thing I noticed in flight was that it would slip in a turn unless you added a little rudder to coordinate the turn. Mine did not like cross winds on take off or landing. Landing are the hard part. It is not forgiving at all. I found full stall landings resulted in less nose overs and bouncing, which it loves to do, usually with something getting damaged. Hard landings will push the wheels back against the wheel pant slot, locking the wheels and causing it to flip.....most likely hard. I extended the slot behind the wheels to allow more room for the gear to flex. Do yourself a favor and make a template of the plywood nose cowl ring. They damage easily and a new cowl does not come with the ring.

Overall the GeeBee can be a pain in the butt, but it has a WOW factor of 10+ at the field. Enjoy but don't get too attached to your GeeBee....LOL.

Rod

Cougar-RCU

My Feedback: (2)

Hello, Is a 16X8 OK to use with the F/S 120SIII ? I am like some of these other
folks here, I have had mine almost done for over year now *lol* but still not
flown her yet. I am REALLY thinking of doing the Robart thing as well from reading
all these post. It sure looks pretty sitting here though ~S~ , I got this bird
cuz my wife like the looks of it. and it will be her plane, she doesn't fly though.
Jeff

rowdog_14

My Feedback: (5)

I flew mine with a 16x8 and it seem to not want to slow down like the 16x6

telejojo

Just ordered one I thnk I'll go with a 26cc gas............

MAGICSWANSON

Mines' still in the box. Still deciding on what engine to use. Here are some pictures that I took of the full-size at an air show several years ago...

Doug

GaGeeBees

My Feedback: (23)

Awesome photos. That's Delmar Benjamin's replica. That boy can FLY! There's some great video on YouTube if anyone is interested.