GP 1/4 Giles 202 balance problems
 

I finished assembling my Giles. I used an O.S. FX 1.60 engine with the stock muffler, a Great Planes 1.20-1.80 engine mount (plastic), a Sullivan 16-oz. tank, a ProSpin 4" spinner, HiTec 605BB servos and Top Flight Powerpoint 18-6-10 wood prop. I have my receiver and 1400mah battery pack as far to the rear of the radio compartment as possible.

My first balancing attempts showed it nose heavy so I put it on the balance with the battery out so I could place the battery along the fuse to find the ideal spot for a battery hatch. It wouldn't balance with the battery sitting on the tail feathers. :(

To balance the plane at 7 1/8" from the LE (GP's recommended range is 3/8" to either side of a 7 3/8" starting point), it needs five ounces [X(] of lead beneath the tail. I use a Great Planes CG Machine for balancing and it has worked well with other aircraft.

Did any of you Giles owners experience this problem? Besides absolutely hating the thought of doing it, I don't even know HOW I'd attach a four-inch-long chunk of bar solder to the tail....

Anything anyone could say to make me feel better would be appreciated. ;)

Good flying,
Bob Scott

RE: GP 1/4 Giles 202 balance problems
 

When did GP change the measurement from the trailing edge of the wing to the leading edge?
My GP G202 manual clearly calls for the CG to be at 9 1/4" plus or minus 3/8" from the trailing edge of the wing. It balanced very nicely at that point with no added weight and flys great with no indication of being nose-heavy or tail-heavy. [8D][8D]

RJ

RE: GP 1/4 Giles 202 balance problems
 

RJconnet

I have been reading all of the threads about the giles 202 for weeks. I have a new one in the box waiting to be built. How does yours fly. I am a little worried about it snapping on me when I land it. I am not a beginner and have several other planes that I fly but some of the people on these threads really bash how this plane flies. I have two engines to choose from which would be the better choice. First is a Moki 1.8 that weights about 41 oz. Second is a Super tigre G-2300 which is the engine that is recommended by GP. I really want to use the Moki as it is new in the box but I don't want to have trouble balancing the plane. My manual also says to balance the plane at 9 1/4 inches from the trailing edge.

Rick

RE: GP 1/4 Giles 202 balance problems
 

desmobob , the tech update is wrong.
You need to adjust the plane to about 9.25 to 9.5 from the trailing edge.

RE: GP 1/4 Giles 202 balance problems
 

Rick,

I am flying mine with a GMS 1.20 which weighs Approx. 30 Oz. add a Bisson at about 6 Oz. and a Dubro motor mount at another 6 Oz. and you have about 42 Oz. The plane weighs just a tad over 12 Lb. this way. It is a very goes where you point it plane. As long as you don't let the nose get too high and the plane too slow with no power on you should not have any trouble landing it. Do not exceed the manufacturers recommendations for elevator throw on low rate until you are used to flying it. With the nose and tail moments of this plane I guess I would have to add about a half Oz. to the tail for every Oz. added on the nose above the above mentioned 42 Oz. So at 42 Oz. the Moki adds 12 Oz. to the nose and would require another 6 Oz. in the tail which would make it a 13+ Lb. airplane with the wing loading getting a little on the high side. My battery is right behind the wing and you might be able to put yours in the tail for a little weight savings.
I also have a brand new ST 2300 and the thought has crossed my mind about installing it in the G202. After not quite a gallon of fuel it is turning an APC 17-6 at around 9600 RPM where the GMS turns the same prop at about 9000 RPM. I really like the way it handles, one back flip starts every time and no dead sticks on my Stinger 120. It does weigh about 8 Oz. more than the GMS. If I were in your position I would be tempted to mount the ST and fly the plane, then later if I wanted more power I would substitute the Moki. Anyway, good luck whichever way you go [8D][8D]..............RJ

RE: GP 1/4 Giles 202 balance problems
 

Ummm... 7 3/8" from the LE and 9 1/4" from the TE is the same spot. :D

I think they changed the measurement from the TE to the LE so people could accurately use Great Planes' CG Machine to measure the balance point. The CG Machine's rulers only go to 7 1/2".

How the heck could my Giles be so nose-heavy? I know my engine is mounted in the correct spot... it was a tight fit up against the back of the mount to get the correct distance to the back of the spinner. It can't really go back any further.

I used a ProSpin spinner from Maxx Products. It is machined from barstock rather than spun like a Dave Brown. I'll take it off and weight it just for curiosity's sake. I think the 4" Dave Brown weighs about 6 1/2 oz. I can't imagine mine is several ounces heavier. I'll find out.

Stay tuned....

Good flying,
Bob Scott

RE: GP 1/4 Giles 202 balance problems
 

I just weighed the spinner. 6 ounces on the nose. Darn it! I was hoping it was way overweight and I could cough up the dough for a new, lighter one and solve some of the problem. Not....

Good flying,
Bob Scott

RE: GP 1/4 Giles 202 balance problems
 

can the engine be moved back some? bisson muff should save some tons over the oem

RE: GP 1/4 Giles 202 balance problems
 

The remote needle valve bracket is just a hair away from the back of the motor mount now. If I relocated the needle, I could move it back maybe 1/4" and would then have to redrill the cowl mounting holes. I also have a hole cut for needle valve adjustment. I'd want to replace the engine mount and cowl if I moved the engine.

Exchanging the stock muffler for a Bisson would probably have me buying a new cowl as mine is cut for the long stock muffler. I have a little concern about this mod as I've read reports of happy O.S. 1.60 owners running the stock muffler and Bisson users having to mess with pumps, plugging muffler outlets, etc. to get the engine running right.

I could do both mods and buy a new cowl. This would be at a cost of about $80 and I wouldn't know if it would fix the problem until I did it. The engine is pretty heavy though, and moving it back a quarter inch may have a significant effect on balance.

On an airplane this size, is 5 oz. of lead as big a deal as I think it is?

Good flying,
Bob Scott

RE: GP 1/4 Giles 202 balance problems
 

RJconnet

I am going to take your advice and mount the ST 2300 on this plane. It was very tempting to mount the Moki though. GP highly recommends the ST and as I have a very new one with about 20 flights on it that is what is going on it. I talked to a friend of mine that flies IMAC with a GP patty wagstaff and she (thats right she) has seen this plane fly with the ST and says it is very good. I value her opinion as she is very good at IMAC aerobatics and setting up large planes. I am very excited about this plane and hope this engine is the right choice. If I don't like it I can always change it later.

Rick

RE: GP 1/4 Giles 202 balance problems
 

Technically you are correct.
The problem is that many people are not getting the position in the same place measuring from the front. That is why measuring from the TE is more accurate.

RE: GP 1/4 Giles 202 balance problems
 

I recently mounted a Moki 1.8 in quarter scale and found that a two piece beam type fiber mount allowed me to move the engine back to where the engine case was almost touching the firewall. The mount I used came from Sig. Maybe you can cut the center section of the Greatplanes mount to allow the moter to slide back even further. Once bolted to firewall the material between the beams of a mount is pretty much useless anyway. Also maybe change needle valve mounting from engine to airframe.

I have always had great results with bisson muffs...so has everyone else hear...never one problem and I am running quite a few to say the least.

RE: GP 1/4 Giles 202 balance problems
 

I decided against ripping everything apart and installing a new engine mount, muffler, etc., and balanced the airplane as-is. First, I mounted the 1400mah battery a good bit back in the fuse using the "battery-on-a-stick" method that I read about in one of the GP Giles threads here.

I ended up having to add three ounces of lead to the tail. My all-up flying weight is 12 pounds, 10.8 ounces as measured on the digital scale at work. I can live with that. [8D]

Now, I just need some flying weather here in upstate NY. We had a bit of a winter relapse today. It seems as if Spring weather will never get here....

Good flying,
Bob Scott

RE: GP 1/4 Giles 202 balance problems
 

Come on down to Georgia and be my guest at the my field! [8D]

RE: GP 1/4 Giles 202 balance problems
 

I have an 1100 mah NiCd four cell pack mounted under the cockpit with the RX mounted behind the tank. Used an OS aluminum mount for the 160 FX. with a Pitts style muffler. Three servos in the tail with a direct connection to an Ohio Superstar tail wheel. Used a DB 4" aluminum spinner with the adapter. 16 OZ Dubro tank mounted forward with a large Dubro fuel valve mounted in the cowling. Used a 1/4 scale pilot, slimline rubber wheels. Used 9 1/4 " from the TE and balanced on the numbers. I would think my tail-wheel connection would be heavier than the one you are probably using. Futaba 9001 servos on the ailerons and 9202 for the elevators and rudder. Futaba S-148 throttle servo mounted in the fuse per directions.

Pictures may help you better understand the set-up.

RE: GP 1/4 Giles 202 balance problems
 

Thanks for the offer! It's forty-five degrees (almost) and windy here today. The lousy weather isn't bothering me so much now, though... a big box containing a new Dave Patrick Ultimate bipe ARF showed up on my doorstep this afternoon. Sweet!

I've only been to Georgia once. Back in the '80s when I was into motorcycle roadracing I headed down to Braselton (sp?) to Road Atlanta to compete in the WERA national finals. It was fall and I was looking forward to some warmer weather than we were having at home. My first night in Georgia I almost froze to death in my tent and woke up to find heavy frost on my motorcycle. [:-]

Good flying,
Bob

RE: GP 1/4 Giles 202 balance problems
 

Nice shots, Roger. I really like the graphics on your Giles.

Do you know what your flying weight is? How's your 1.60 do on fuel? I also installed a 16-oz. tank. I was a little concerned when mine emptied the 10-oz tank on my engine test stand in less than five minutes during break-in. [X(] It does a little better now and will no doubt improve some more as it gets broken in and the mixture leaned a little.

I'm looking forward to flying mine!

Thanks for you help,
Bob

RE: GP 1/4 Giles 202 balance problems
 

Bob, using a bathroom scale with me on the scale, with, and without the airplane, mine weighs roughly 12 lbs. Not the best method so give or take maybe a half pound. I get 12 minutes flying time and have about 1/4 tank remaining. I tested it once at WOT and it drained the fuel in 15 minutes. New and on a test stand, set very rich, the fuel ran out much much faster as well.

As you probably know, the 160 needs a good smoke trail on the high end. Test your settings on the low end to make sure she will run up without sputtering. Adjusting the needles on this engine is an art form. I have a 160 in a P-51 that sat up all winter. I flew it last weekend and didn't have to make any adjustments to the needles. Once set, the 160 requires minimal adjusting. Until the engine is really broken in well, make sure you don't get too far away from the runway and stay high in the event of a dead-stick. Here again, once broken in with the needles adjusted right the 160 performs very well.

There has been much posted on this airplane. Either you love or hate it. I happen to really like mine. Tracks very well on take-off with no bad habits. When landing just don't get too slow. Be prepared to do a go-around because she will soar, due to ground effect low to the runway, and eat up a good bit of runway before touching down. Just don't have your elevator throws set too aggressively on your maiden. She will snap with too much elevator throw. Test up high to get the feel.

Better to be a bit nose heavy, especially for your maiden flight.