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Carl Goldberg Extra 300 balance question

Old 07-19-2004, 10:16 PM
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sledman
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Default Carl Goldberg Extra 300 balance question

I replaced the OS .91 Surpass on My Goldberg Extra with a Webra 1.20. I've added just over 4 ozs of weight to the tail, and it still balances nose heavy. So far, I have flown it once at about 4-3/4", and it flies terrible there compared to how it used to fly, although it's no longer under powered.

What is a good balance point for this aircraft?
Old 07-23-2004, 10:29 PM
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bralex
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Default RE: Carl Goldberg Extra 300 balance question

Sledman,

Try balancing the plane at 5-5.75 inches. That is what the plans specify that I have. We have one of these beauties, and it flys great with a YS 120 and no added weight. Balanced one inch further back will make things alot easier for you and the plane will fly like it's supposed to! Good Luck!
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Old 07-23-2004, 10:45 PM
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aviti
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Default RE: Carl Goldberg Extra 300 balance question

I also have a YS 120 on mine...servos mounted up front so I had to add tail weight. Great flying plane...too bad the control surfaces aren't larger. I'd like to have one with all the surfaces enlarged to do some 3D. Anyone ever try this?
Old 08-08-2004, 08:25 AM
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Default RE: Carl Goldberg Extra 300 balance question

I have a Zenoah G23 in mine with the battery pack in the tail and balanced as per the plans, and even with the additional 11 ounces of engine weight up front over the original ST G90, it still flies great with almost unlimited vertical.

It is so economical to run plus with none of that messy after flying glow fuel stuff to clean up.
Old 11-28-2004, 11:47 AM
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Default RE: Carl Goldberg Extra 300 balance question

OK guys, thanks for the advice. I relocated the rudder and elevator servos to the tail, relocated the fuel tank to the CG in the center of the fuse, and it is ready to go. Balances right at 5-1/2".
Now, it just needs to warm up outside! Snowed yesterday, clear today but a high of 37.
Old 11-28-2004, 12:10 PM
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Default RE: Carl Goldberg Extra 300 balance question

I'm pretty sure that balanced at 5.5" you will like how your plane flies. What size prop are you using on your 1.20 engine.

As I recall, the plans specify a single aileron setup for .60 size engines, hopefully you are using dual aileron servos for the 1.20 engine.
Old 11-28-2004, 02:29 PM
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Default RE: Carl Goldberg Extra 300 balance question

Yes, there is a seperate servo for each aileron, as well as a seperate servo for each elevator half. I also upgraded to new high torque servos.
Currently, I have an APC 16X8 prop bolted on. Not sure what that will do, but we'll find out soon I hope!


ORIGINAL: karolh

I'm pretty sure that balanced at 5.5" you will like how your plane flies. What size prop are you using on your 1.20 engine.

As I recall, the plans specify a single aileron setup for .60 size engines, hopefully you are using dual aileron servos for the 1.20 engine.
Old 11-28-2004, 09:24 PM
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Default RE: Carl Goldberg Extra 300 balance question

I used 5 standard size BB servos on mine and retained the 'Y' elevator pushrod system using a single servo.

I toyed brieftly with the idea of changing to a split elevator system, but so far it has just been a thought, as to date the arrangement as is has worked perfectly after umpteen flights.

That 16x8 APC or a 17x6 prop should turn in the 8-9k region and should provide ample umph for your model....enjoy.
Old 12-01-2004, 11:34 PM
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Default RE: Carl Goldberg Extra 300 balance question

The only real reason I went to seperate elevator servos, is the elevator halves weren't linked, and I needed a little extra tail weight with the pumped Webra 1.20. In fact, that tail weight issue is the reason that the servos ended up in the tail. Then it only made sense to install a larger fuel tank , and reposition it in the fuse at the CG point. Snow showers are supposed to come to an end soon here, and barring an inversion, I might actually get to fly it this weekend. I said might..........
Old 12-02-2004, 08:35 AM
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Default RE: Carl Goldberg Extra 300 balance question

I'll keep my fingers and toes crossed for you that the weather wakes up in your favour.

Here in the Caribbean your type of climate is unheard of, as at worst all we have to contend with is wind and rain.

Hope you do get a chance to put in a couple....enjoy.
Old 11-21-2022, 11:37 AM
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ve3cga
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hi all, just about finished a sctatch built extra300 here.
Just wondering how you modified things to get a bigger tank to go back to the spar
did you have to notch out the leading edge of the wing back to the spar?
Going to be installing a YS110FZ and I'm sure it could use a larger tank
Old 11-21-2022, 04:10 PM
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My model is fitted with a 12 oz fuel tank which is a straight fit and my G23 gas engine is quite miserly with it's fuel consumption, so that size tank easily gives me about 20 minutes of run time. I tend to limit my flight times to just about 10 minutes or so,so I have quite a reserve of fuel left after each flight.
Regarding fitting a larger than stock fuel tank, I definitely would advise against cutting into the wing's leading edge to accomodate one.

Last edited by karolh; 11-21-2022 at 04:16 PM.
Old 11-22-2022, 02:28 PM
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ve3cga
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thanks,
after doing a little research I see a sullivan square tank 12oz thats 5" long
the front tank area is 5-1/2" so that will fit

The local hobby store had a sullivan 10oz tank and I almost bought it and ordered a second to have a 20oz fuel tank, ty wrap them together and have one feed the other
They also had a Dubro 12oz. it would just fit but no room for vibration foam. 2 dubro 8oz would fit for a 16oz tank
but 12oz will be enough
If I switch to gas I'm afraid the plane would have to be kept in the garage due to gas fumes
but I certainly see the advantage for flite times
Old 02-04-2024, 11:50 AM
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ve3cga
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well its feburary still not maidened the extra, either too much rain, or too windy. flew an electric ultimate stick in a heavy snowfall but until now there hasnt been any decent weather to fly the extra
I ended up putting my mds148 on the plane.
yes its a brute.. I flew an extra230 and an edge 540 both 78" wing span and it flew those great.
Oddly the fellow who gave the extra had a 3/4" wrench taped to the rear fuse

now back to balance on this extra,
I want it a little front heavy, so far with my fingers are slightly past the front balance point on the drawing its where I would say is fairly good with 7 oz of weight as far back as I can on the fuse
This seems ok but my fingers are 5-1/4" 5-3/8"from the leading edge
I hoping this is good I really dont want it too tail heavy

supposed to be good weather for the start of the week as long as there isnt wacky wind

I took the YS110fz off the plane, it wasnt running smooth in the cold and I have used this mds148 dozens of flites in the winter, at this point its more reliable



Last edited by ve3cga; 02-04-2024 at 11:51 AM. Reason: spelling

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