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    • All Forums >> RC Airplanes >> Giant Scale Aircraft - 3D & Aerobatic >> RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
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    RE: Composite-Arf 33% Gee Bee R2 - First Flight -... - 7/8/2008 3:01:16 AM   
    RichardGee



    Posts: 110
    Joined: 10/10/2002
    From: Dixon, CA, USA
    Status: offline     		The good news ... and bad news...

    My Gee Bee weighs in at 32 pounds dry. This will increase a bit with the addition of pants and spats, but not by much.

    The Bad News - it balances at 100mm from LE. This equates to 23.5% of chord.
    Shown perched on my modified EZ Balancer, the scales (and balancer) DO NOT LIE.

    On BOTH model and full scale, the ideal balance point is determined to be 18% of chord. This equates to 75mm back from LE.

    Correction will require re-arranging a number of components inside the aircraft.

    I had organized internals as instructed in manual and utilized DA 150 (notice cooling baffling built into cowl which also added nose weight). However, plane is still tail heavy (I worried about and suspected this as plane came together, so it is not terribly surprising ).

    I could omit pilot bust to help balance, but HOW can a Gee Bee fly w/o a pilot!!!

    Fuel and smoke tanks are right on CG so filling should have little to no effect.

    Those of you using lighter engines, BEWARE!!

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    _____________________________

    RC Modeling is for truly talented individuals... for everyone else, there's video games.

    (in reply to PTS)
           Post #: 201

    RE: Composite-Arf 33% Gee Bee R2 - First Flight -... - 7/8/2008 3:14:24 AM   
    RichardGee



    Posts: 110
    Joined: 10/10/2002
    From: Dixon, CA, USA
    Status: offline     		FLYING WIRES -

    First, I IGNORED the manual's stated lengths and opted to determine correct lengths on my own using good kite string. I found actual lengths to be different than those stated in manual, but could not recall for you what the actual lengths should be - this will likely vary from model to model due to production tolerances and where each modeler locates the mounting holes in wings and fuselage.

    I wrote down the EXACT required lengths - HOLE TO HOLE - and determined how to chop up flying wires accordingly. You will be cutting the 4 flying wires into 2 sections each, creating 8 separate flying wires.

    Obviously, one end of the SS flying wire will have the forged threaded end, and the other end will require you to SILVER SOLDER a brass fitting that has been flattened, drilled, and bent to conform to mounting dimensions.

    Proper soldering requires a VERY POWERFUL soldering iron or brazing torch, good flux and Silver Solder.

    As the instructions state, "The flying wires are what HOLD YOUR GEE BEE TOGETHER IN FLIGHT" There can be NO COMPROMISES in properly constructing the flying wires.

    I used a grinding wheel to fully rough up the soldered end of the SS wire before soldering. I also cleaned with lacquer thinner. Once constructed and mounted.....
    The entire affair is tightened via the flying wire "cables" that go from inner gear mounts to bottom of fuselage. Once tightened, you can actually pluck the lower cables and they will 'sing' - Anything less than this, and you are asking for an in-flight failure OR a ground loop and flip over due to wobbly gear.

    I have not yet flown this R2, but DO have experience flying a quarter scale R2.
    ROCK SOLID LANDING GEAR are integral to landing successes.

    _____________________________

    RC Modeling is for truly talented individuals... for everyone else, there's video games.

    (in reply to PTS)
           Post #: 202

    RE: Composite-Arf 33% Gee Bee R2 - First Flight ... - 7/8/2008 4:30:55 AM   
    PTS


     

    Posts: 422
    Joined: 10/25/2003
    From: ROSWELL, NM, USA
    Status: offline     		Thanks for the explanation! On we go . . .

    (in reply to RichardGee)
           Post #: 203

    RE: Composite-Arf 33% Gee Bee R2 - First Flight -... - 7/10/2008 2:01:43 AM   
    dwr


     

    Posts: 225
    Joined: 10/29/2004
    From: ft.myers, FL, USA
    Status: offline     		Richard, your GB came in light. Hope you can move enough so you don't add weight. Mine should be about 33lbs. See post 188. I put the tank on the firewall like Jim did and everything else I could.
    even the rudder servo is up there. The 3W100 is heavier than a DA 100 so that helped too. I am getting close but looks like I won't maiden till after a short trip up north. Should be ready about Aug 1st tho. DWR.

    (in reply to RichardGee)
           Post #: 204

    RE: Composite-Arf 33% Gee Bee R2 - First Flight -... - 7/10/2008 2:30:19 AM   
    RichardGee



    Posts: 110
    Joined: 10/10/2002
    From: Dixon, CA, USA
    Status: offline     		Right from the start, I was a little wary about locating rudder and elevator servos and Rx all the way aft, but that is where the instructions (and mounting parts) dictated. It also seemed the Fults "tail wheel" (modified from nose wheel unit), although sturdy, was on the heavy side. I still have not added TW fairing, but it should be extremely light.
    I have yet to add canopy clear plastic, but again, should not affect balance much.

    All during the construction process I kept lifting tail and wondering how in the world I was going to make the thing balance, even with a DA150 in the nose...

    Have you balanced yours yet with the 3W? All OK?

    I am in the process of mounting all batteries and voltage regulator on back of firewall. Will recheck balance after that. If need be, I will add an another battery pack or just switch to larger (4300 instead of 2200 Lipo's). I don't really like the idea of on-board RC gear being anywhere near engine or ignition, but I have no choice. Hopefully, my trusty Futaba PCM Rx will reject any noise...

    Will provide update and pix when I have them.

    _____________________________

    RC Modeling is for truly talented individuals... for everyone else, there's video games.

    (in reply to dwr)
           Post #: 205

    RE: Composite-Arf 33% Gee Bee R2 - First Flight -... - 7/11/2008 4:34:12 AM   
    dwr


     

    Posts: 225
    Joined: 10/29/2004
    From: ft.myers, FL, USA
    Status: offline     		Richard, balance was 75 MM with 1 1/2 lbs balast at dummy engine location. I have three 2600 mah li-ions at the firewall. PCM reciever is on the bottom of fuse just forward of the side door.
    I had all components and pilot in the fuse at approximate locations when I balanced it. I'll balance again when everything is installed permanently. Right now fighting with the canopy. DWR.

    (in reply to RichardGee)
           Post #: 206

    RE: Composite-Arf 33% Gee Bee R2 - First Flight ... - 7/12/2008 8:18:41 AM   
    BigProp



    Posts: 46
    Joined: 4/13/2002
    From: Livermore, CA, USA
    Status: offline     		Well, in reading this thread, you guys have inspired me. I placed my order for a C-ARF GEE BEE today. I will be using a 3W 120 B2 for my power plant.
    I am a novice builder, so any tips or tricks that you could pass along would be greatly appreciated. Looking forward to getting it built!

    -Gio

    _____________________________

    I hate it when I land Inverted!

    (in reply to dwr)
           Post #: 207

    RE: Composite-Arf 33% Gee Bee R2 - First Flight -... - 7/13/2008 4:58:01 AM   
    RichardGee



    Posts: 110
    Joined: 10/10/2002
    From: Dixon, CA, USA
    Status: offline     		DWR,

    Well, it's back to the drawing board for me and this #@%&$@@!!! Gee Bee . It's going to require 2.5 pounds on the firewall/dome to get it to balance at 75mm from LE... and this is after mounting Rx and ignition batteries, ignition and voltage regulators on the back of engine dome, adding cowl baffles and engine dome reinforcement !!!

    Had I known this was going to be the case with CG, I NEVER would have installed the radio tray and servos where recommended in the 'manual'

    This is quite disappointing, I must say, and baffling since I pretty much followed the instructions (as poor as they are) to the letter and, of course, have a DA150 on the nose.

    I found that just a Great Planes pilot bust makes a HUGE difference in CG, but cannot possibly imagine the plane w/o a pilot in the cockpit.

    My next steps will be to substitute 6 cell 7.2v NiCads (RC CAR style batteries) for the LiPos. These are heavy monsters that will deliver more than enough power, while also serving a useful purpose - nose weight.

    I believe I will also need to move at least the rudder servo and Rx and the piezo gyro WAY forward - which entails remaking all my servo extensions, rudder pull/pull, TW control and all the various cable anchors I have installed... WHAT A MAJOR PAIN!!!!

    I could also drill some lightening holes in the rudder front (inside fuse)...

    Not sure how this happened... makes me wonder if the manufacture of my particular Gee Bee resulted in heavy aft end fuse and other components...

    _____________________________

    RC Modeling is for truly talented individuals... for everyone else, there's video games.

    (in reply to dwr)
           Post #: 208

    RE: Composite-Arf 33% Gee Bee R2 - First Flight -... - 7/13/2008 4:47:01 PM   
    dirtydingus


     

    Posts: 67
    Joined: 8/8/2007
    From: west palm beach, FL, USA
    Status: online     		Hey DWR,

    Don't get discouraged. First contact Aircraft International they make foam pilots that look good and are weightless. On the issue of nose weight, if you fill the inside cowl leading edge lip with the smallest buckshot that you can get, and then pour in epoxy, that will put the weight much further forward than putting it on the dome. 2 lbs. on the dome would equate to less than 1 lb. in the cowl leading edge. Also, the wood I added to hold the baffling in place is 7-ply 5/16 birch-ply, more weight in the right place. This way the baffles are screwed in place after the cowl is on, giving full access to the motor and cowl bolts. I think these simple things should put you in CG ballpark.

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    < Message edited by dirtydingus -- 7/13/2008 4:48:03 PM >

    (in reply to RichardGee)
           Post #: 209

    RE: Composite-Arf 33% Gee Bee R2 - First Flight -... - 7/14/2008 2:10:55 AM   
    RichardGee



    Posts: 110
    Joined: 10/10/2002
    From: Dixon, CA, USA
    Status: offline     		THANKS for the suggestions.

    I will very likely arrive at some combination of additional weight, batteries and equipment shifting to arrive at the correct CG.

    I am not discouraged, just a little T'd off at CompARF's sub-standard instructions...

    I WILL forge ahead as this airplane is simply my all-time favorite.

    _____________________________

    RC Modeling is for truly talented individuals... for everyone else, there's video games.

    (in reply to dirtydingus)
           Post #: 210

    RE: Composite-Arf 33% Gee Bee R2 - First Flight -... - 7/14/2008 3:27:56 AM   
    dwr


     

    Posts: 225
    Joined: 10/29/2004
    From: ft.myers, FL, USA
    Status: offline     		Hey Jim, this time Richard is doing the cussing instead of me. I am still ****ing a little but at least I can smell the finish line. It is amazing how bad the instructions are. My copy says they are temporary but I think they have been that way for years. More evidence CA lost interest in this airplane long ago. Jim did you get your engine back in yet? Richard, I agree about the pilot, gotta be there for those low flybys. DWR.

    Gio, welcome to the group. If you have read the entire thread and still bought the beast then you certainly belong in this looney bin. DWR.

    < Message edited by dwr -- 7/14/2008 3:31:14 AM >

    (in reply to RichardGee)
           Post #: 211

    RE: Composite-Arf 33% Gee Bee R2 - First Flight -... - 7/17/2008 7:42:10 PM   
    BigProp



    Posts: 46
    Joined: 4/13/2002
    From: Livermore, CA, USA
    Status: offline     		Has anyone made up a "laundry list" of extra parts to buy for this plane? I am trying to go through all the control surfaces and see what I should be shopping for that was not included in the small hardware bag that came with the "kit". Any help would be appreciated. Thanks!

    -Gio

    _____________________________

    I hate it when I land Inverted!

    (in reply to dwr)
           Post #: 212

    RE: Composite-Arf 33% Gee Bee R2 - First Flight -... - 7/18/2008 1:06:00 AM   
    dwr


     

    Posts: 225
    Joined: 10/29/2004
    From: ft.myers, FL, USA
    Status: offline     		Gio, didn't make a list. I think everyone pretty much uses the heavy airplane hardware they have experience with.

    Well I'm puttin on the Kirby Graphics set. Finally got to the fun part. Will be up north a week. Should be ready to maiden a week or so after I get back, approx Aug. 1. DWR.

    (in reply to BigProp)
           Post #: 213

    RE: Composite-Arf 33% Gee Bee R2 - First Flight -... - 7/24/2008 3:05:54 PM   
    RichardGee



    Posts: 110
    Joined: 10/10/2002
    From: Dixon, CA, USA
    Status: offline     		GB Gents:

    Still waiting for my heavy 6 cell 4000 mah battery packs to be available so that I can balance my GeeBee. These will be used in place of the Lithiom batteries I had originally planned to use, thus, I can leave in place voltage regulators, et, al. Not sure if these will do the trick or if rudder servo will need to be relocated way forward. Won't know for sure until I get packs installed and this porker back up on the balancer.

    One of the contributors commented that I had used ball links on the CompARF phenolic control horns - which is a big CompARF NO-NO. I concured that indeed, CARF instructions for their large