rev

I have 5 flights on the Gee Bee and the wheel pants are cracking at the seams. Called pac. and he said I was the only one thih a problem and they were not under warr. so a orderd a pair $50 ok I can live with that. they arrived today and they are cracked the same as mine,so I called again and sent pic. no one else has a problem. I got a $15 dis. I am not a happy camper !

AndySteere

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First flight on mine today! Went perfectly! :thumbup: Pics and movie clips at the website (click on pic, or follow link below).



I let my friend (and instructor) Carl Johnson test fly it. Lost the tailwheel during the taxi test (you can tell it's gone in the pic above)... but we didn't even notice until getting ready to fly it again. At that point I decided it was time to go home and recheck all other screws before flight#2. As luck would have it, Carl found the tailwheel in the grass of the runway... but couldn't find the wheel-collar... despite urging from us to keep looking.

The RCS140 is running fine, but still needs a bit of tweaking on the carb. The provided mount makes adjustment of the high-side needle difficult. It is enough power for decent flight. Nothing very fast, and it's likely to run out of steam quickly on vertical lines. I won't really even judge that until a dozen more flights. The engine should start loosening up a bit by then... only half way through its first gallon now.

Rev, sorry to hear about the wheelpants... and your experience with their customer service. The seam you are talking about is the one down the middle in front, and the crack is from the bottom side up?

ChinookPilot

Andy,

Can't download the clips of your plane. Am I the only one having this problem? Error message says that the server can't be found.

Sam

AndySteere

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Sorry about that... put them in the wrong directory. Try it again!

Jimmy Bananas

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Andy:

Do you know Dave Ragsdale?????

AndySteere

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Jimmy,

I do indeed. Don't see him all that often, he flies out of Sturgeon. I believe he is a RCU member, but I'm not sure of his username.

danmilo

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Andy, great job documenting the assembly and flight of your "Y". The amount of information and the schematics really knocked my socks off.



Dan

AndySteere

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Thanks for the comments about the website guys! I haven't really added much commentary to this one, compared to the P-47. I may add some additional "notes about the photos" at some point. I will also have additional flight photos and movies, so check back periodically.

azuz

from the looks of it.....it should be called a monster RACER !: )


cheers

Carlos Murphy

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Do ya think a 3W 70i (rear carb) would be too much for this plane?
(considering your added nose weight)

AndySteere

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Hey Carlos,

Short answer: The 3W-70i seems like an awesome engine, but way too much for this plane... both in power and weight. Save it for a bigger airplane.

Long answer: That engine weighs more than 5 pounds... without mount, prop, mufflers, etc. The RCS140 weighs ~3 pounds ready to fly. I only needed 4oz additional to balance. The 3W-70i also produces enough power (>50 pounds of thrust at full throttle) to possibly tear the wings off the GBY... sorta like Florence. Even at idle, that large prop (24x10 or 26x8) will be generating enough thrust to make landings very interesting. The RCS-140 generates ~15 pounds of thrust at full throttle. The ZDZ-40 is at ~25 pounds of thrust... and I would put that as the absolute max I would personally recommend.

Carlos Murphy

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Ya, I figured as much.
I haven't looked at it in a while, it's all wrapped in a box on my engine shelf, forgot how big it realy is.

Howard Davidson

Well guys, a flying report. It wasn't mine but a good friend who flies scale with me. He got his about a month ago and had it ready for a test flight in about three weeks. He's a perfectionist so that probably accounts for the time period. He installed a G-23 size engine and it's fairly new so I don't remember the name. It was listed in the "New Items" section of MA a couple of months ago. The test flight day was great except for the wind. At least it was down the runway at about 15 to 20 mph. We had checked the CG before the flight and it was right on the mfg. recommended spot. The flight went perfectly and uneventful. Only a click or two of trim on anything was needed. After the flight he said the CG was a bit too far aft and would move it up a bit. He later flew it and was pleased. He's a good pilot so it really didn't matter. The plane was just a ***** twitchy for a pretty scale job. The landing gear was great. Not like the GiantScalePlanes P-26 piece of junk.(I speak from experience!!) You definitely don't want to smack the landing though, there's bounce in them thar gear!! Robart struts look tempting!! His overall weight was right on the spot also. He didn't have any bad comments on the plane or the flying. If it's in one piece come October he'll have it at the Memphis Belle Classic. So far his only ***** has been the waiting period.

Jimmy Bananas

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Well I make all the repairs on the landing gear ( new landing gear blocks,pants and wire) and flew it again a few days ago..G-23 and APC 17-6 prop and everything went OK..added a little more power on landing,so no more problems there,I hope....Am very pleased with this model, and I'm a happy camper now....For a giant flying ARF,it's one of the best around....

fgpierce

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Jimmy... Glad to hear all went well and now you can look forward to enjoying it. A little power on landing does make a big diference.. HUH

As for the giant scale P-26 yes the early ones were not that good in some areas especialy the legs. The have made realy nice improvements. Yes, you can argue that they should have done it in the first place! But the fact is that they saw the glaring problem and did something substantial about it along with a host of other things. Namely far better fiberglass in the fuse,cowl and wheelpants. Then they have gone and painted all fiberglass blue and white and red trim stripes. I have to give them credit for some realy nice improvements. At least they give a hoot as to the quality of there product

I should also know because after loosing my first one to a battery. I had to get another about 1 month later!
And I dont regret It

Rubber side down boys

ELROB

Have been flying mine for about a week now and what a sight to see and hear. I must be the only one to have use a Saito 170 R3 and I have to say this plane was made for this engine. Using a 16-8 Zinger prop at 7800 rpm it tracks evenly down the runway(grass), requires very little rudder, the tail comes up and it lifts off as gentle as a bird. Does not look or sound like a "flying potato". After trimming my pilot put it through some manuvers(big loops, tight loops, rolls) and it behaves just as you would expect it to. With the McDaniel 3 cylinder on board driver w/ a 4 cell 1300 ma battery pack mounted just behind the fuel tank the balance was perfect with no additional weight required.
For cooling the 170 I followed Jim Feldeman's instructions for cutting the dummy engine as follows:
Cut away the #1 cylinder(top) and the space on either side of it. Then cut away the spaces between cylinders 3 & 4 and the space between 5 & 6 and don't scrimp on the amount you take out at these two points. I also cut a radius at the front of the tunnel cut-out on the cowl. Clean up the cowl mounting standoffs and you should get about 1/8th inch clearance between the cowl and fuselage.

AndySteere

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Like Elrob, we've been flying mine about a week. Lots of nice comments from everyone who sees it fly. Six flights and about 40 minutes of flight-time on it now (I'm trying to keep a log). Plenty of updated pics and video clips on the website. Had to open up the cowl exit area some more to keep the engine happy. I got some tips from RCU member Jemo on break-in and carb tuning, which helped the low-end of this, my first gas engine.



Some additional thoughts on the model:

* The RCS 140 provides adequate power for scale flight (~55mph top speed, currently 8500rpm with the APC16x8), and a few basic aerobatics (like rolls, small to medium sized loops), but it runs out of steam quickly if you deviate from a straight flight-path. Lots of drag. You can hear the air going around the cowl and wheelpants when it flies by. Coming out of a shallow dive up into a stall-turn poops out at about 100 feet. This should improve some once the engine gets a few hours on it.

* Flight controls are very effective. The model responds instantly to any change you make, but it's very precise and predictable. Some might describe theirs as a bit twitchy (or some similar spelling ), but I really like how mine handles. Perhaps the outrageously-expensive ball-bearing linkages are helping here (or maybe that's just me trying to justify them). Servos are nothing fancy... Hitec 645MG on the rudder, and 425BB's on everything else (running 6-volt).

* The GBY's rudder is about the cleanest that my friend/test-pilot/instructor has every seen (and he's flown LOTS of rudders). Basically no roll-coupling at all. It will do a very nice "show pass" (a pass down the runway rolled 45-degrees toward the flight-line and held in a straight line with opposite rudder). 4-point rolls are fairly clean for this kind of aircraft. It will even knife edge without much fuss, though it looses altitude slowly.

* Haven't noticed anything bad about the ground handling. Upgraded the tailwheel to a 2" Klett and am happy with that choice. When coming up on the throttle for take-off, it does want to pull left more than my TF P-47... but nothing unexpected from a big taildragger. A touch of right rudder and she is straight again. The wheels have noticeable toe-in, which may be helping the ground handling.

* Landings have been uneventful. My first landing did a couple very light bounces (~6" high), but the next landing was textbook. We have to cut the engine to idle a few hundred feet back from the threshold or it will float right on by. The idle is set pretty high (~2500rpm) for these first few flights. I will be sure to heed your warnings about leaving it little in it.

* I did notice that after a flight with high-G maneuvers, the wing struts on one side came out of their holes in the wing. May try to make the dowels a tad longer... though I really don't plan on doing much high-g flying. We were just wringing it out to see what it would do. Perhaps the two snap rolls (one inside, one outside) we tried were a bit beyond what should have been tried.

* I deviated from the instructions on the elevator servo placement and wiring. I put both elevator servos in the top holes, both servo arms pointed down, ran another extension to an unused channel, and am mixing them with a JR8103. This is working very well and I haven't noticed any differential or tendency to roll out or tuck during any maneuver, including high-G. All throws set to exactly what the manual recommends.

* The GBY likes rudder-coordinated turns. Sure, you can do it with just the ailerons, but try adding in some of that rudder for a much better looking turn. Some TX's allow you to automatically mix the rudder into aileron control. We tried this on mine and it seemed to work nice. Not necessary though, its easy enough to do it manually.

Next flights for the GBY will probably be the Taylor Missouri fly-in next weekend.

jrf

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Andy: Did you set up the aileron differential per the instructions?

Jim

AndySteere

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Sure did... 1.25" up and .75" down on both sides. Are you seeing something in my description or video clips that would indicate otherwise? I have been kinda curious as to what the differential does?

AndySteere

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After thinking about this some more, let me rephrase. There's nothing wrong with the aileron-only turns... they are as nice as any plane I've flown. However, a rudder-coordinated turn produces a flatter, "more scale", and in my opinion a better looking turn.

jrf

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The down aileron creates both lift and drag. The lift raises the wing to bank the airplane but the drag pulls that side of the airplane back, which is away from the direction of the turn. You might think that the forces on the other aileron would be the same in the opposite direction, but this is not the case. The drag created by the down aileron is greater. In some configurations a lot greater.

This effect is called adverse yaw, and you can see the airplane raise it's nose and drop it's tail in aileron turns.

Differential aileron travel, where the ailerons travel further up than down, if done correctly, balances the drag on the two ailerons, eliminates adverse yaw, and makes the the airplane track accurately through turns.

It is not a problem if you like to use rudder to flatten your turns. I was simply questioning the need. The GBY, WITH DIFFERENTIAL, tracks extremely well through aileron turns in either direction.

Jim

AndySteere

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Jim,

Excellent! Thank you for the explanation!

I agree, the plane tracks very well and doesn't NEED the rudder to make clean turns. To me it's sorta like the wing-struts... doesn't need them, but looks better with them.

Carlos Murphy

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Andy,
Some airplanes don't even have ailerons!
They will have a flap on top of each wing near the tip. When the plane needs to bank right the right flap raises pushing the wing down while at the same time NOTHING is happening on the left wing. This is not a new thing, this system has been used since the fourty's.

pmmartin

I flew my Gee Bee "Y" today. It is an excellent flier. I flew with an APC 20x11 e prop. Yes an e prop as I have done an electric conversion and it is fantastic.

I will post more details and some pictures soon.

Paul Martin

fgpierce

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Electric???

What do you have for battries? You must be hooked up to Hoover Dam or Niagra Falls!!

AHhhh! I get it ! you've converted It to U-control because of the Power cables!!

I all seriousness ,I would like to hear what you used for a Motor, battries, How much does it weigh and what are your flight times so far.

Good going but, I would never have guest it and a 20x11 to boot!