RichardGee

My Feedback: (156)

Jim,
I have mixed throttle/rudder per instructions such that at full throttle, rudder is deflected (right) at exact angle as molded-in vertical fin. As I throttle down to idle, rudder returns to neutral.
Have you found this to be at all close to what actual flight conditions require to offset P-factor??
I have also installed gyro on rudder as I have found this a helpful addition to any short-coupled airplane.
I agree that DA100 would have been sufficient power, but it appears my CARF R2 will need every bit of nose weight available via the DA150.

btw: Wayne Parrish reported his was clocked at 138 mph w/3W 120 on the nose.

dirtydingus

RichardGee,
I found that setting to be right on. I also found that the 50mm right and left rudder deflection was way to much, the rudder on this thing is wicked powerful. I have 25mm on each side and that is a little overkill. As for speed, Wayne's Gee Bee is as fast as mine with the DA 150. I was clocked at 138 - 139 and 140.7 with no wind and a very shallow dive. Thats haulin' but for a big tub like this.
Jim

RichardGee

My Feedback: (156)

I kind of thought the instructions "50mm each side" were off the mark. As a matter of fact, you would likey concur that the instructions in general leave much to the imagination...
I also paid no attention to the flying wire measurements and instead, used string to get the exact distance and cut the SS flying wire material accordingly.

I found my 25% R2 to have a VERY sensitive elevator, until it got close to stall speed, then, zippity do dah. Does the same hold true for this bird?

Do you wheel land or 3 point?
This seems to be a point of controversy, as Adrian Page swears a 3 point landing is the least dangerous... and Byron gave the same instructions for their R2.
However, I found a wheel landing to be not only scale, but the least risky in terms of an inadvertant stall or aileron reversal by slowing down too much.
Your experience?

What throws are you using for elevator and aileron?

Do you leave all flying wires attached to fuselage when transporting?

What propeller are you spinning on the DA150?

dirtydingus

RichardGee
3 point always for me but I may try main wheel if I had another 500' of runway.
Not sure of other throws, will measure them tomorrow.
Yes, I leave the wires on the fuse. and tuck them in where the gear meets the center section.
I am running a 28x14 Xoar but I may switch back to the Mejzlik 30x12 for better vertical.

PTS

My Feedback: (153)

I started to do some work on the GB this weekend primarily repairing a little shipping damage on the trailing edge of the rudder post with one side being crushed about the size of a dime, and the other side cracked gel coat. I would have been disgruntled if I did not want to paint the plane. I found some great composite repair from Aircraft Spruce called SUPERFIL http://www.aircraftspruce.com/catalo...s/superfil.php. This stuff is light, extremely tough, and sands great. Also after reading I will do a rebuild on the CA struts as well. I will also be using a set of 7" CB Heavy Duty wheels that I purchased from SIG. I will post pics and weight of these tomorrow.

I do plan on running the RCS 250 Radial but I have to come up with a way to convince the wife to use vacation money to buy the engine. Now my priorities are straight...

Perry

quist

My Feedback: (198)

Perry, Modelers can also purchase Superfil from Don's Hobby shop in Kansas. It's only draw back is cure time.

dwr

My Feedback: (1)

Jim, thanks for the flight info. Very interesting about the landing speeds taken with the radar gun. It is great to get all this information on an aircraft has more than a few ways to bite you.
This thread it great. DWR.

CHAWKJIM

I have been repairing autos my whole life . When I repair composite I use any type polyester filler, you can get this from any auto paint store, they have several brands to chose from,I prefer the cheaper one, they always seem to sand easier. It also has little to no pin holes.

hotrodblazer

Jim, I'm thinking about your statement that you three point land your Gee Bee,but with the modified tailgear that you have, it sits at a angle of attack similar to a plane up on the mains only.Your tailwheel is on the ground much sooner than one with a scale setup would be.This probably enhances control on landing, especially the zone between loosing rudder effectiveness and gaining tailwheel steering control.

CHAWKJIM

Is that carbon fiber mat were the antenna is routed?

RichardGee

My Feedback: (156)

Yes, my antenna is routed inside fuse and YES the fuse does have some CF matting.
I am aware of the potential signal problems and am prepared to re-route my antenna if necessary.

This is my second CompARF. I am currently flying a 2.6M Extra 260, same Futaba RX; antenna completely inside fuselage and have experienced rock solid radio performance, regardless of channel; and regardless of other aircraft broadcasting.
With engine running (DA100) I can do an antenna-collapsed range check at over 50 yards with no issues.

I am hopeful the Gee Bee will be similar.

dirtydingus

hotrodblazer
Most of the more successful C-Arf gee bee flyers I have seen, use a very large tailwheel with the original set up for better control and that also puts the tail up about where mine is. The only drawback I can see is that it may be a bit more susceptible to a nose over. When I taxi through the grass I have to be very carefull. The tail has bounced up once enough to strike the prop($60). I talked to someone a while back who was using a 3.5" tailwheel with great succsess. This picture shows one at least that big. Jim

RichardGee

My Feedback: (156)

Maybe it's just me - and I readily admit to being a "purist" - but if I have to begin to deviate from the scale outline of the Gee Bee R2 in an effort to make it handle better, I lose interest quickly.
There are plenty of non-scale Gee Bees available or a modeler can scratch build one, altering the planform as much as needed to arrive at a better handling airplane, but then it's no longer a Gee Bee R2.

Other than better brakes, Delmar Benjamin and Steve Wolfe chose to adhere as closely as possible to the scale fidelity of the original R2.
I feel similarly.

It was the exact outline of this 31% CompARF that first attracted me, followed by the many positive performance and kit reports.
Don't want to start a controversy, but my goal with this aiplane is to reproduce a scale model of the real R2 and to adapt my flying skills (not the model) to accomodate.

dirtydingus

I could not agree more, the two things I have changed on this plane (spinner and tailwheel) Have been nothing but a headache. If I had it to do all over I would leave it the way it was meant to be. I have even considered changing it back but the weight penalty of a re-paint would be significant. This plane handles better on the ground than you might think, in my opinion keeping the tailwheel assembly scale will be a plus.
On the other hand, it would be a pretty bland world if we all subscribed to a cookie cutter mentality.

CHAWKJIM

I'm sorry but the flames are way cool. I would never even consider to change the paint . Your paint is perfect.

hotrodblazer

I also give the flames a big thumbs up! I saw the flight video before I was able to see the close-up pics. The video was somewhat grainy, and did not give the paint job justice.I felt the black was interesting,but when I was able to see the flames on the pics,I loved it!
The Gee Bee was the ultimate hot rod back then,and if the Granvilles were doing it today, I am sure it would have a flamed paint job,nitrous oxide,and fuzzy dice hanging inside!

dirtydingus

hotrodblazer,
That was possibly the most profound thread I have ever read. I had never thought of it that way but I agree 100%. Thanks, Jim

Flyjets

My Feedback: (51)

Got to hand it to you Guys I never thought that your Gee Bees would have survived this long.

dirtydingus u make any new videos?

I am going to stop in at Kermit Weeks place and photograph Delmar Benjamin R2 starting to get the GeeBee bug myself.

Been thinking about this project for a while now.

http://www.airworld-usa.com/scale5_page.htm

Video of her flying here.

http://www.airworld-usa.com/videos_page.htm

Ian

dwr

My Feedback: (1)

Well CA had estimated when I bought the GB at Top Gun that the shipment would get to them about May 10 and I should see mine about the 15th. I thought at the time that this was most likely just an optimistic guess but darned if the thing didn't show up today! The Box was in perfect shape and the plane was too except for one crack in the gell coat at the aft end of the fuse. So I guess mine is like the rest of them.

As I checked everything out I found that the upper Aft former had been epoxied in crooked making the upper rudder hinge point about 1/4 inch off center. Something else to fix but again not a big deal but.....

Also wonder about the cowl mounts being installed flush with the back of the cowl? Shouldn't these be set forward about an inch to get some overlap? Changing them will be a pain. Any thoughts on this anyone?

One last thing, regarding landing gear mount location. There are no reference marks on the fuse wing root as a starting point to measure the recommended shift forward. Guess I figure that out from the reliefs on the wing root. But I wonder If those are still in the old location.

Jim, could you give me the measurement from the leading edge to the center of your forward gear mount? Your location seems to work well.

Still can't get over how big this thing is! DWR.

RichardGee

My Feedback: (156)

DWR,

My Gee Bee arrived with a crack in the gel coat at the aft end.... am beginning to wonder if Delmar's had the same thing..

Cowl Mounts - well, sorry to say, mine was the same except that one of the aluminum mounts was even installed crooked. I let Andy Kane know that I could fix them, but that I would prefer a new cowl... then got to thinking that 3 straight cowl mounts does not fix the over riding problem of their location at the far aft end of the cowl.

My solution has been to make all new cowl mounts out of ply. This involved also cutting grooves into the CF matting around the existing mounts so that my ply mounts could actually go into a sort of 'slot'. I have yet to reinforce my new mounts with CF matting, but will be doing so.

I also cut off the existing aluminum mounts and filed them down.

The entire 'solution' locates the cowl properly in relation to fuselage and engine and actually makes the Gee Bee exact scale length.

YES - it's a PAIN!!

I'm sure there are better ways of doing it, but the existing aluminum mounts are so well matted in with CF, epoxy and filler, it might be even more of a pain attempting to dig them all out without damaging the cowl.

I can post pix if you like.

dwr

My Feedback: (1)

Richard, thankx for the response, and pics of your modification would be great. How far did you set them back from the aft edge? I also wonder about a good way to install the control horns in the elevators and ailerons and the aileron servoes for that matter. With thin skins and foam or nothing at all in the middle whats the recommended way? I find nothing about this in the instructions.??
DWR.

dirtydingus

DWR,
I'm glad to here your plane showed up in good shape.

From L/E to center of front gear mount hole is 2 3/16". I am looking foreward to you guys getting your planes in the air so we can compare flight characteristics. I still have a few issues I need to resolve.
One thing that bugs me is, when you make a hard turn to the right at full throttle the nose wants to drop and you need to ad a touch of left rudder to hold it up. When you make a hard left turn the nose wants to climb and it does all this trimmed for hands off, level flight. Also when I come down the backside of a loop it has a tendency to roll off to the right. Other than that it is a nice flyer.

RichardGee

My Feedback: (156)

In deference to dirty dingus, I must say that the measurement from my wing LE to center of first gear mounting hole is 2 and 3/8"

This is because rather than shifting the gear forward a full 20mm, my measurements indicated approx. 15mm was the scale location. This is, of course, splitting hairs, and I would defer to Mr. dingus as he one of the few who has repeatedly flown this thing and lived to tell about it...

As far as elevator and aileron horn mounting, I have cut large slots in the elevators and used cut fiberglass and 3 hr. epoxy mixture to glue and fill. I purposely made the openings larger than the horns to allow adhesive to surround the anchoring point. I also roughed up the phenolic horns with 60 grit sandpaper to provide some "tooth" and cleaned them with lacquer thinner before gluing.
I used this same method on my 102" CARF E260 and it has performed flawlessly for a year of aggressive flying.

I have yet to install the aileron servos so cannot speak to that.

Indeed, the Gee Bee "manual" is more of an outline than thorough instructions. I helps very much to have lots of (large) building experience and CompARF experience beforehand. It seems they could update the instructions w/o too much pain...[>:]

I will post pix of my cowl mounts ASAP

RichardGee

My Feedback: (156)

I have included pix of my cowl mount mods. The main mounting portion is of 1/4" aircraft ply with 1/8" ply side reinforcements. I actually cut grooves into the existing CF matting, epoxy and white filler to tightly fit the 1/8" ply side reinforcement pieces.

How far back? Well, it really depends on how you want cowl to line up with fuse and engine. You will notice that the two side shots of two different mounts show that one was barely set back - right up against the existing aluminum bracket. Another mount required a hardwood spacer between it and the existing aluminum bracket. YOU CANNOT ASSUME THE EXISTING BRACKETS ARE ALL IN THE RIGHT PLACE.
The entire affair was tedious in that I had to mount engine, then bolt 1/4" ply main cowl mounts to front of fuselage/engine dome; then slide cowl on until everything lined up perfectly and cowl snugly contacted ply mounts. Lots of trial and error, filing, sanding of ply until I had a tight fit.

I had previously cut off aluminum brackets with hacksaw and really roughed up (w/Dremel) existing contact points for ply mounts.

Once the fit was perfect in relation to engine, prop, fuse front, overlap, etc., I removed cowl and applied some epoxy where main ply cowl mount pieces would contact; slid cowl back over; kept everything from moving with pieces of foam shoved around cowl; and let dry.

After this was done, I added 1/8" ply side braces with epoxy and glass filler and clamped. Then I added kevlar reinforcement. And that is where I am at right now.

I will sand and smooth and very likely apply some black paint over the entire set up to help hide.

As I previously stated, the existing aluminum mounts, while very robust, were TOTALLY WRONGLY PLACED with one being very crooked. This has been the most disappointing part of my CARF GBR2 experience.

The second disappointment is having to make all my own hatches (8) for wing / flying wire attachment points. Still working on that part.

PTS

My Feedback: (153)

Looks Good! Thanks for the pics and the explanation.

Regards,

Perry
PTS