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Old Jul 01, 2006, 10:18 PM
It wasn't my fault!!
Headspin's Avatar
USA, MI, Midland
Joined Oct 2004
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Spitfire CoG

I know this has been covered before..

But I would like an up-to-date opinion on the CoG of a Spitfire.

I'm using an outrunner and a 3s1300 Lipo stuffed vertically (almost) into the nose from underneath and the nose cowl holds the battery in. This works great.. my bird is 13.5oz unpainted and the CoG is 54mm from the leading edge.

Is this too nose heavy?? It says 60mm is the way to go but I also read that 55mm is good too.

How far is too far and can I compensate with trim.

btw.. it was that long since I installed the motor I forgot what it is, but it came with a 30AMP ESC and 3 free props fro 45 bucks (ish) like 8 moths ago.

Power is awsome.. I have to really hold it tight when I wind it up

Thanks for all replys. Jeff
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Old Jul 02, 2006, 01:01 AM
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kensp's Avatar
Darwin Australia
Joined May 2002
6,960 Posts
The wing, the fuselage and the tailplane on the GWS Spitfire are unchanged so the arguments about the CG will also be unchanged. I am still in favor of 62 mm from the LE at the center.

Ken
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Old Jul 02, 2006, 10:22 AM
It wasn't my fault!!
Headspin's Avatar
USA, MI, Midland
Joined Oct 2004
793 Posts
I tried so hard to make it so I wouldn't have to add weight..

Looks like I went too far.. I guess I need to add a tailwheel or something.

Thanks.
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Old May 10, 2008, 04:35 PM
It wasn't my fault!!
Headspin's Avatar
USA, MI, Midland
Joined Oct 2004
793 Posts
Revive an old thread here..

I moved house.. poor Mister Spitfire got put in a shed until one nice day when it's owner decided to clear out and get straight!

Well.. I've been having fun with an Acro Bipe and as he wind was down I thought it would be a great day to try out the Spit (thats right.. I never flew it yet)

I wanted to get more experience with the Moth first but that had a bad day a while back and it's become a "to do" thing..

So it is maiden day.. yahooooooooo..

First throw.. I gave it some tiny prop just to help the glide.. thump! right into the ground it went.. no damage..

I try again with a bit more throttle.. wheee.. it wants to do several things at once and I instinctively try to fly it rather than get it down safely..

Anyway.. I do both and have a nice landing..

It was yawing and right banking so I pinned the rudder again as it wasn't straight for some reason.?. and I compensated with airlerons.

Ready again.. off it went.. this time it was buzzing a bit.. and away it went.. I had to give it some "up" eleavator and it was still banking to the right.. I try to trim in but it starts to get scary.. I give it a handful of throttle to get some air under it.. still trying to counter the banking as the extra throttle does more wiered stuff and I end up with it right over my head doing I have no clue what..

THUMP..

More of a SPLITfire now.. I glue the three parts I now have back together..

To cut a long story short.. this thing needs a brick tied to the nose to make it balance!!

just repeat the above nightmare twice more (once into a tree and once into a plowed field) as I try and trim and fly at the same time.
I feel I'm well forward of the 60mm mark.. I think I need 45 - 50. I have the 3 cell stuffed up into the nose from the front.. putty in the spinner and the rest in the undercowl but it just feels tail heavy still.

I did get some good flying in even though it was pretty short lived.. Did a couple of loops.. more by accident than anything haha

I'll get there eventually.. but day one and I'm out of props already..
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Old May 10, 2008, 06:49 PM
It wasn't my fault!!
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USA, MI, Midland
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Before and after.. about 70 minutes work
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Old May 12, 2008, 04:00 PM
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Lexington, Ky
Joined Apr 2004
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I never had any CG problems with the Spit set at the factory specs. Balance it inverted on your thumbs, with the nose hanging down slightly. Whenever I hear of someone having problems with the Spit my first thought is control surfaces with too much movement or someone launching it WOT with a brushless motor.
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Old May 12, 2008, 04:55 PM
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Darwin Australia
Joined May 2002
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Quote:
Originally Posted by Condre'
I never had any CG problems with the Spit set at the factory specs. Balance it inverted on your thumbs, with the nose hanging down slightly. Whenever I hear of someone having problems with the Spit my first thought is control surfaces with too much movement or someone launching it WOT with a brushless motor.
I agree with Condre'. The GWS Spitfire is sensitive to elevator control throw. My Spitfire will loop by just pulling in full up trim. To desensitize the elevator I only use a throw of 6 mm up and 6mm down on the elevator.

My Spitfire hand launches well even with a brushless outrunner running on 3 cells. Just have the model well trimmed so you donít need to apply any control inputs for the first 3 seconds. But 3-cell operation makes my small Spitfire too fast and responsive for this old mans eyesight and reactions.

Ken
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Last edited by kensp; May 12, 2008 at 05:14 PM.
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Old Aug 29, 2013, 08:17 PM
It wasn't my fault!!
Headspin's Avatar
USA, MI, Midland
Joined Oct 2004
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From the ashes

HAHA... I was just looking at this old thread I started.. WOW.. I totally destroyed that poor spit but NEVER threw it away.

5 years later.. I put it all back together again and today I "re"-maidened her.. She flew great..Well, after a little trimming. Loops rolls.. probably too much for a maiden

I did figure out the the initial problem though.. it was STUPID PILOT ERROR haha..

I attach a pic of this poor FrankenSpit - Thanks GWS !
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Old Sep 18, 2013, 08:41 PM
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Folks what size spinner does the GWS Spitfire take?
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Old Sep 19, 2013, 01:05 PM
It wasn't my fault!!
Headspin's Avatar
USA, MI, Midland
Joined Oct 2004
793 Posts
I think this is as good as it gets..

GW/SPN008A

Although.. my GWS Mustang came with a great one.. If I can find out how to get that on the Spit, I'll post.
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