Magic 3-D CG ??
07-29-2003, 03:17 PM
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Magic 3-D CG ??
I recently bought two of these used here at RCU and I have read alot about the cg being 4.5" for the plans. I have a OS 46fx(standard pipe) all standard servos,and a 4.8 flat pack mounted above the aft servo mount.with it setup like this the plane is way tailheavy at 4.5" and I have read that most guys are at 5"-5.25" from the LE. I am using a GP cg machine to balance with.When I move the cg to 5" the plane is super nose heavy.So should I leave it at 4.5" or try to get it to 4.75" ?? 
07-29-2003, 03:53 PM
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Magic 3-D CG ??
It's going to fly fine anywhere in there, to be honest. It's not terribly critical,
as far as making it unflyable or anything. Just set it to suit your style.
On the one you got from me, I had made a couple ink marks on the fuse,
but I'm not sure if they're still there or not. (probably not). Anyhow, I last
flew it with the battery back above the servos on the rails I added, and
with an OS .46 SF up front. Seems like I added an ounce or two in the tail opening.
as far as making it unflyable or anything. Just set it to suit your style.
On the one you got from me, I had made a couple ink marks on the fuse,
but I'm not sure if they're still there or not. (probably not). Anyhow, I last
flew it with the battery back above the servos on the rails I added, and
with an OS .46 SF up front. Seems like I added an ounce or two in the tail opening.
07-29-2003, 03:57 PM
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Magic 3-D CG ??
That sounds kinda wierd. You know the "nose" is the end with the engine on it, right? 
The manual says 115mm. I settled on 5" from the LE with my battery on top of the servo's at the back of the wing bay. Mine had (yes had ) a 50SX and Slimline Pitts muffler up front.
Mine was a bit twitchy at 5" but a lotta fun! I gotta go make sure my engine is on the correct end....
The manual says 115mm. I settled on 5" from the LE with my battery on top of the servo's at the back of the wing bay. Mine had (yes had ) a 50SX and Slimline Pitts muffler up front.
Mine was a bit twitchy at 5" but a lotta fun! I gotta go make sure my engine is on the correct end....
07-29-2003, 04:22 PM
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Magic 3-D CG ??
yep got the right end I must be having one of "those days" I am lost for words here. I set my cg rulers on 4.5" its way tail heavy and then set the rulers on 5" it is nose heavy. I guess I am losing my mind. Now if I make a mark at 5" on the wing tips and balance with fingertips,it's a tad tailheavy. I guess I will try it like that,if I loose it I got another in the shop. 
07-29-2003, 04:40 PM
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Magic 3-D CG ??
Check the balance as close to the fuse as possible.
The 5" from leading edge comment, is measured on the fuse side.
Can't recall if it makes a difference on the Magic or not, but sometimes there
is a HUGE overall difference between 5" at the fuse, and 5" at the wingtips.
And if you set your stands at 5", and it seems nose heavy, add weight until it balances there.
(Or 4.75, or 4.5, or wherever you want it balanced at, ultimately.)
The 5" from leading edge comment, is measured on the fuse side.
Can't recall if it makes a difference on the Magic or not, but sometimes there
is a HUGE overall difference between 5" at the fuse, and 5" at the wingtips.
And if you set your stands at 5", and it seems nose heavy, add weight until it balances there.
(Or 4.75, or 4.5, or wherever you want it balanced at, ultimately.)
07-29-2003, 04:59 PM
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Magic 3-D CG ??
Very good point this thing does not balance right,this is taken from the instructions for the Magic.The plane cg is before engine mounting.
SPECS: Wingspan: 52" (1320mm)
Wing Area: 725 sq in
Weight: 3.5 lb
Wing Chord: 14" (355.6mm)
Airfoil: Semi-Symmetrical High-Wing
Center of Gravity: 4.52" (115mm) Back from the wing's leading edge
before engine is mounted. Control Throws- Low Rate High Rate
Ailerons: Up & Down 1" (25mm) 1.40" (35mm)
Elevator: Up & Down 1" (25mm) 1.40" (35mm)
Rudder: Right & Left 3.14 (80mm) 4.33" (110mm)
SPECS: Wingspan: 52" (1320mm)
Wing Area: 725 sq in
Weight: 3.5 lb
Wing Chord: 14" (355.6mm)
Airfoil: Semi-Symmetrical High-Wing
Center of Gravity: 4.52" (115mm) Back from the wing's leading edge
before engine is mounted. Control Throws- Low Rate High Rate
Ailerons: Up & Down 1" (25mm) 1.40" (35mm)
Elevator: Up & Down 1" (25mm) 1.40" (35mm)
Rudder: Right & Left 3.14 (80mm) 4.33" (110mm)
07-29-2003, 05:59 PM
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Magic 3-D CG ??
Before engine is mounted?
They must be talking about temporarily strapping the engine down with rubber bands,
so you can slide it fore/aft to get the proper balance, is all I can figure.
The plane should definitely be balanced with the engine in place.
Just balance it between 4.5" and 5" from the LE, at the fuse, to start.
It will be well flyable anywhere in there, and you can tinker with it later.
They must be talking about temporarily strapping the engine down with rubber bands,
so you can slide it fore/aft to get the proper balance, is all I can figure.
The plane should definitely be balanced with the engine in place.
Just balance it between 4.5" and 5" from the LE, at the fuse, to start.
It will be well flyable anywhere in there, and you can tinker with it later.
07-30-2003, 12:35 AM
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Magic 3-D CG ??
My instructions instructed me to mount the engine temporarily and move it fore and aft to help the balance. I tied it on with thread. The wife was mad at me for trashing her sewing stuff too...
In the end I had the 50SX as far back as I could anyway...
me to mount the engine temporarily and move it fore and aft to help the balance. I tied it on with thread. The wife was mad at me for trashing her sewing stuff too...In the end I had the 50SX as far back as I could anyway...
07-31-2003, 08:39 PM
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Magic 3-D CG ??
I mounted an OS .46FX on mine with all the gear in the only place it would fit - in the front. Had to attach 3 oz. of lead in the tail to get 'er to balance properly. This was all based on setting the CG at 4 3/4" from the LE.
The Magic is not real picky where the CG is set and will probably vary from plane to plane. When all is said and done, you will have to find the appropriate CG to suit your own taste.
As far as the instructions that come from the manufacturer - it's kinda like the covering they use on the plane - garbage! But it is the most fun flying piece of garbage I've ever flown.
The Magic is not real picky where the CG is set and will probably vary from plane to plane. When all is said and done, you will have to find the appropriate CG to suit your own taste.
As far as the instructions that come from the manufacturer - it's kinda like the covering they use on the plane - garbage! But it is the most fun flying piece of garbage I've ever flown.
