Decided to not mount throttle to firewall, as I am not keen on letting the servo pickup unecessary oil, dirt and grime, even though the servo is a relatively unexpensive Hitec 311. You will see in following photos that I recut anothter servo tray to accommodate three servos instead on two. The bottom tray cut-out will house the throttle servo. I am using Dbro flex cable, which is routed through two popsickle sticks for support. The white glue looking material joining the former and fiber-glass fuse is CA soaked Arm & Hammer baking soda. I found that it make a good filler for joining fiber-glass and wood.

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hi all

new here

worlds slowest/worst typest!!!!---
below is shortest version i could make.

was googling GP GEE BEE and found this thread and have read more than half but not all post(ordered mine today)
only long term problems with gee bee seem to be spar failure and landing problems.is this correct everyone?

spar joiner failure
as i have almost always on scale race/military/aerobatic planes used 50% larger engine than max recomended i always do the following

1 make the spars/center section as strong as possible with and/or spruce/aircraft ply/aluminum and carbon strips and or glass

2 add stressed flying wire or struts(close to scale usualy!)

3 similar mods as 1-2 for elevator and rudder

4 beef up fire wall with glass---usualy from inside

this has always resulted in airplanes that you can not rip the wings off if you try---I TRY TO!( i fly at the limit)

added weight not a problem when landed like full size fighters and other heavy weights.

LANDING HEAVIES
we all learned to fly with low loading trainers and moved on to low loading sport planes ect--i call all(most) of these floaters.what we learned here wont work with high wing loads.

after reading discriptions of these landing misshaps and the discriptions of landing procedures used and the procedure in the gee bee manuel i think i can help with the problems---i might be wrong--40+ years of this hobby and i still have stuff to learn.

i learned how to do this from my jemco p-47 manual--span 50? engine 60+ weight max 12lbs mine was at 10 1/2lbs(real high wing loading--double gp geebee?) and the constant proding(harassment) from some older flying buddies.
jemco said(my 20 year old memories) not to atempt to fly this airplane(p-47) if you have not mastered high wing load skills--you will crash it.and then told how to modify midwest ind molded foam .21(.25?) chipmonk with hot .40+ and lots of added weight for a heavyweight trainer.

my version of landing heavies and making 3 point landings every time with no bounce.
make high pratice landings atleast 50ft high. 9 is very important for gee bee as in cross wind the large fusealage will block air flow from the down wind wing and aileron.

1 start final well out and high

2 low power setting

3 start pulling slowly back on stick until sink rate increases to more than you want.hold this elevator seting durring next steps and all the way to roll out

4 add power until sink rate is like you want.
play around until you find proper sink rate at around 1/4-1/2+up elevator and 1/4- 1/2+ throttle--varries from aircraft to aircraft and wing/power loadings.some where close to the aircraft level with ground durring final(slight to moderate nose high to flight path attitude--or 3 point attitude)

5 now fly some pratice at these settings using throttle for altitude and elevator for speed(this is not a typeo ---is backwards from floaters!)

6 you may have to move elevator around for gust ect--dont stop hands on flying!

7 i usualy set up slightly to much sink rate and may go as high as full throttle before tuchdown to flatten out flight path-i like to be at full up when wheels make contact---throttle should be chopped to idle at tuchdown.the wing should be at or near stall at touchdown.

8 to abort go to full throttle and let off stick slowly until feel is developed--some planes may drop nose if you let off elevator to fast.

9 now learn to do this while crabed in cross wind---rudder to nose into wind oppisite aileron to level wing if needed.

now we are flying(landing) like a real fighter pilot!
and we have good elevator/rudder control from prop wash and will not run out of elevator--ailerons may get soft.
no lag spooling up engine and no flame out due to an engine that has cooled down during an idle/glide making aborts faster/cleaner/safer.
less tip stall---dont realy know why on thisone!

when landed like this you will find that the airplane needs less correcting from gust ect and it will not bounce around near as much and will feel rock solid.

this can be learned with almost any airplane by adding weight. as you get the hang of it add more weight(slowly) until the wing loading is higher than anything you can belive.
when you have this mastered you can land anything that will fly and make it look easy(it realy is once learned).

nothing i hate more than unbuilt airplanes except for instant re kitting of fine airplanes!

cant wait for my gee bee to show up!
will post mods as i build--possible 30cc engine--see how it feels in when its in my hands.


thanks guys and i will keep checking this thread for more info and problems and have gotten some good ideas from what you have already done.

Thanks
David

David,

I can't say I've heard of any spar failures, but the landings are a challenge. Your landing procedure sounds like it's worth trying. I know that long setups are definately required on the GeeBee. Unfortunately I can't fly mine again cause our field is going through some realignment and until that's done we have a limited approach. That's the main reason I had issues on my second landing....you just can't whip this bird around on final and have it settle down in a short pattern.

Thanks for the input and let us know how your GeeBee goes!

Steve

Hi Steve

should have said spar joiner failure as john crisp reported on his(also a 30cc)aparently john lives 1hour south of me--insane power must be a southern addiction!

after you get real good landing like this you will be amazed when one day in an emergency you will have to slam it through final turn close in and set it up for heavy weight landing and plant it on the runway in an instant --3point no bounce no sprung landing gear!

this bring up someting else---do not land this way dead stick---dead stick is fly more like low wing loading landings.

also- belive it or not the tower arf .40 trainer will almost do a heavy type landing--with low power setting(the one ive done it with is my sons 2 x crash repaired slightly heavy and beat up 15 year old airplane with os .40

i cant sleep while waiting for the gee bee!


David

Glued in stab today. Thought I would post picts just before going off to work. Did have small gap at bottom of stab. I used baking soda and CA to fill after letting 6 minute epoxy set up.

oops!
should have said----dead stick landings--keep nose down till untill almost on runway!

i donot have gee bee in hand yet so i donot know if it has built in wash out at tips.
if not---it is suposed to be covered with monokote wich will allow twisting washout into wing and reshrinking covering(if wing is not ridged as 2x4)if no supplied flying wires i will also adjust these to hold some washout in wing.

finaly got pic of my big toy loaded!

will try to load model pics soon!


David

David,
The GP GeeBee has no provision for flying wires. You can add non-functional ones using elastic cord, plastic cord, etc, but I'm not sure how you'd make any functional enough to to any warpage correction. I almost added them to mine for scale effect, but for now I've not messed with them.

Steve

Steve

it will get flying wires--the power i like and the way i fly the wing will fold shortly on 99+% of the kit i or scratch built plans i have ever dealt with(example-140 mph art chester jeep doing vertical 8 loops ect the size of control line stunt planes-g-forces would kill a human pilot)after 10+years of competing(and winning) in c/l combat and rat race in 70s i just dont know how else to have fun with r/c scale types!-do love flying my pt-19 though(at scale speeds)

will cut peep holes in covering(from bottom)and see whats there and if need be uncover it and add spruce or carbon strips to existing spars--and also make the peep holes where i can add flying wire mounts--probably .030-050 6061 t6 aluminum sheet.have lots of this laying around from monoque race car construction and repair.also ply webs.

the landing gear/fuselage mounts (for wires)will be fairly easy to do--cut slot with dremel and insert aluminum angle from inside.
the ones on the fuse will also need to be continuous from side to side(from sheet alum)so as to relive the stress on glass fuse and carry the load continuously through the structure.

hope fully the wing has enough ribs to handle compression loads from the flying wire loads!--dont look foward to building a new wing but will if needed as the loads can crush structure along length of span--like an accordion.

will use cable for wires and large threaded clevises(with lock clips) for adjustment--not scale but best way i have found over time--adjustable and strong.

anyway have not seen kit yet so not sure what will be needed.figuring out ways to solve above things dont let me sleep so i will be glad when it arrives so after looking and about 2 more sleepless nights deciding how to do it i can get back to normal--what ever that is!

when i draw my own large scale race planes i like to use angle or square tube aluminum spars for 1/3 to 1/2 span--nothing like security!

did you have any problems during construction?

thanks for your input and feed back as this is invaluable.

hope you field is ready soon so the gee bee can fly!




thanks
David

David,
Just about the only gripe I've heard about construction was the fit of the belly pan. Wasn't a problem for me, but I guess for some it's not simple enough. The pan needs to be trimmed and adjusted to achieve a good fit, but it's not something you can just glue on. Sounds like you're not one to shy away from a little modification so shouldn't be a problem for you.

It will be interesting to see what you think of the wing. Most folks who are kit builders find ARFs to be a little underbuilt. I know when I had my hard landing the wing didn't stand up and the Robarts twisted right back through them, so If I was building the wing I'd probably add some more structure. When I got my new wing set I save the old ones. Someday I might take the covereing off the old wings and fix them up with some toughter materials.

Steve

How do you start the motor? I am new to RC Planes and love the Gee Bee. How do you attach the glow starter or is it done remote or ob board glow?
Thank you.
MarkyD

I'm using a Ram On Board Glow.

Steve

Not sure what you mean... can you explain how it works?
Marky D

I'm using an onboard glow driver made by RAM electronics, the Ram 50 to be exact. It has a C-cell, 1300Mah nicad and supporting electronics that hook to the throttle servo using a Y-adapter. You set it up to cut on at idle to keep the plug hot. It serves two purposes; it keeps the engine idle at low RPMs for reliable which allows for better reliability at low RPMS, and you also use it instead of a standard glow driver for starting. It works great. I can get my OS120 pumper to idle very nicely. I'm using these on all my larger 4-stroke engines.

Steve

Thanks... I get it. Sounds great, can you add it to any plane? markyD

I don't use on board glows on any of my four strokes and they all idle fine. I have a 120 in my geebee it flys great. I did NOT have to add any extra weight at all, I have the throttle servo fixed to the bulkhead under the engine, I like my throttle servos in the cowel you get a much better positive linkage and the fuel residule does not do them any harm. I have a plane where the same servo has been fixed to the side of the engine mount for ten years. The standard four cell RX pack is under the tank and the CG is where suggested on the instructions.
Regards
Paul

havent been on line in awhile as the gee bee modifications have occupied most of my time lately.

it is assembled and waiting for me to decide what engine to use --was planing on using 30cc poulan but have found a score in the cylinder plating(down hill from here)may use the 46cc poulan thats for my scratch built mulligan(verry detailed at 23lbs)

things i like about the gee bee
1-fuselage is fantastic--
2-all glass work is verry good!
3-fit of parts pretty good

things i dont like
1-not enough ribs in wing
2 piss poor sanding job on wing
3-landing gear blocks are wrongly placed for max strengh
4-wing should be fully sheeted.
5-tail wheel design is not right--could lead to broken rudder/post and striped servo gears.
6-if i glued aileron hinges in in factory slots the would be at an angle that would have caused the aileron reversal to be worse.
7-decals are wrong size and not complete(like the missing hill bros streamliners)
mods i did.(1/2 pound gain in weight)
1-load carring flying wires--wheel pants have added structure and lower wire loads are carried by the wheel pants.
fuse has added structure to carry upper wire loads
wire atatch point on wing--not as strong as i would like on the front wires as there is no rib or internal structure in this area so the loads are carried by the planking
the rear wire attach point is through trailing edge and is better.
not real pleased with wing wire attach points but all i could do without uncovering wing.
these mods should still add 50% to the g-loads that wing can handle.
2-landing gear atachment method was changed to allow failure at this point instead of destroying wing(mabey)
3-tail wheel set up replaced by propper sprung unit.
4-wing to fuse joiner replaced(front half of center ribs)with 5 ply aircraft ply wood--this also carries lower wire loads.
5-rudder control horn mounted internal and set up to correct linkage geometry problem(dont want rudder differential!)
6-firewall will be moddified(beefed up)once i decide what engine to use
7-used real hinges on all surfaces(dubro 1/4 scale)
8-added wheel pant to tail wheel

facts on full size r1/r2 super sporters(read henry haffkeys book on gee bees)
1-first flight was made with no verticle fin(i have picture of this version)test flight showed it needed a little more fin/rudder and this was added the next day

2- dolittles original remarks do not indicate that it was any harder to fly than anyother race plane or fighter of the day.
his later coments on how bad it was were aparently to make him self look more like a hero.

3- the moments and area ratios of the super sporters were about the same as all of the race planes using the wasp.

4- these aircraft r1/r2 --one was damaged on roll out after landing-short grass runway-the othe was damaged on take off almost imediatly after because the pilot was pissed at other pilot for damaging first one and he jerked it off the ground and stalled it.these 2 aircraft were built into the long tail r1-r2 and was damaged on testflight landing(short grass runway agin)
5-have read delmar benjamans(builder/owner/pilot of fullsize replica)flight report on the r-2 and the main problem is aileron reversal at low speed high angle of attack--the most comon cause of this is that the downward movement of the aleron causes that wing to stall first causing that wing to drop
the cure for this is wash out and aileron diferential
the wash out can be set with the flying wires or by warping the wings and reshrinking the covering
##### aileron diff can be done with the linkage geometry real easy and should save everyone lots of grief!######you want more up aileron than down

bottom line--nice airplane for the $$

wish-that we could buy unbuilt wing kit or kit with unbuilt wing with double the rib count(atleast) and ready to apply covering so that those of us who need a stronger more scale wing can do it our way!


David

Does anyone know or understand the rudder differential setup for this plane. The instructions call for the control horn to be set back from the hinge line 1/8 inch. Why?

I went and got large horns for the rudder and ailrons so the attachment point would hang over the hinge line like the pictures try to show.

I built my all stock with a OS 120 pump. I added a slightly larger tank, I also added 2 sticks to tie the fuel tank bracket together across the interior of the fuse to keep the tank from wiggling on that flimsy piece of plywood.


I also cut the wheel pants so they only covered half the wheel and used 6 oz cloth and expoxy and tripled the interior with reinforcement since I fly off of grass.

rudder diff

reason --cheeper/easier---but wrong

fixed mine by bending up a sheet aluminum horn and mounting it inside thr rudder with sheet metal screws from the outside and bored a hole through the rear of the fusealage for push rod/horn clearance.the horn to pushrod joint is on the centerline of hinge now and when right rudder is aplied the horn moves into fusealage--hope this made sense.

looks like it will be alittle while befor i mount engine/radio as just bought out another machine shop and have to add onto shop.

David

Almost finished.

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Alright, I just purchased one of these Gee Bee's. I am having trouble deciding between a YS 1.10 FZ or an OS 1.20 Surpass II pumped. What would you all suggest for this bird? Also, I got the Robart robostruts. Should I cut the springs, or leave them full length?

Thanks,
Neal

Can't be much help regarding the struts, as I installed the stock gear and beefed them up by sandwiching wood between the fore and aft sections. Engine wise though, I dropped in a Super Tiger G2300. It is a nice fit, dummy engine and all, and the balance is right on the 2 3/4 mark. I know from experience that the MVVS 26 IFS is interchangeable with the ST G2300 and the OS 1.20 four stroke engine mount. The MVVS gasser is a great little engine and the weight difference is of little concern and will easily fit under the cowl. I am not sure about the 70 deg. pipe pitts muffler for the MVVS but Bisson makes it for the ST G2300.

If you are leary about purchasing the G2300, don't be. With the stock carb, you simply break in the motor as per instructions. After that, you first find the high end peak by leaving your glow driver connected, lean it until it starts to sag, and back off t he needle about an 1/8 of a turn. Next, you find the lowest idle poin, again leaving the glow driver connected. Then, disconnect the glow driver and listen for the rpm's to drop at this idle setting. This will indicate that you will need to lean the low end a tad more. Continue doing this until the drop in rpm is almost undectable. Next, set the mid-range. The mid-range setting will undoubtably be a bit rich. To lean the mid-range you will loosen the fuel nipple housing screws after scratching a mark to denote its original location, and then turn the unit counter clockwise 1/16 turn at a time, until the rapid advance of the throttle develops a smooth transition.

I have four of these engines and each one is a little different in that one mid-range adjustment may require more movement on the nipple housing than another. I think what throws many guys is the fact that the high-end is not as sensitive as other makes of engines. Also, a couple of my engines have developed air leaks between the carb housing and carb neck. If you can't seem to seal this area, the Perry carbs (non-pumped version from Tower Hobbies) have worked beautifully. They offer more sensitivity to the high-end needle setting as well. Hope this was helpful.

Finally finished!
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I'm just about finished with mine.

The G23 seems pretty heavy, so I added 1/4 inch plate to the inside of the firewall, for added strengthy. I had to move the motor forward, for cowl clearance. The added weight up front necesitated moving the servos to the back of the radio compartment. The 1300ma battery will be mounted 3 inches back, in the rear fuselage.

All comments are welcome.

The MVVS Gasser is a great candidate for this project. I currently have one mounted to an 11 3/4 pound Sukhoi. It's vertical is superb and the engine is very reliable.