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Speed,Combat,Scale,Racing => Combat => Topic started by: Dwayne on November 27, 2009, 11:49:19 AM

Title: Gotcha 460 first flight (update)
Post by: Dwayne on November 27, 2009, 11:49:19 AM

Took the gotcha 460 out for it's first flight and it flys with the out board wing up, I lined everything up using an incedince meter so I'm stumped. I didn't use any tip weight as the engine runs clockwise so I didn't think I'd need any. I'll try lining everything up again and add some tip weight and try again.

Well I decided to go ahead and cut it up and start again, I reinforced the engine mount and again I'm lining everything up as I go I hope this one flys better and the mount does'nt come lose.

Title: Re: Gotcha 460 first flight
Post by: Mark Scarborough on November 27, 2009, 05:32:09 PM

Hang the plane from the leadouts and see if the vertical CG is out of line. Is the muffler hanging below the centerline? if so, then this would cause  it to fly outboard tip high. What does it do inverted? if its tip high upright and inverted, then its tip weight ( or a warp) if its tip high upright, and tip low  inverted then its likely the vertical CG being off.

Title: Re: Gotcha 460 first flight
Post by: Gary James on November 27, 2009, 06:49:38 PM

Quote from: Mark Scarborough on November 27, 2009, 05:32:09 PM

Is the muffler hanging below the centerline?

Muffler?  On an AMA combat plane?

Title: Re: Gotcha 460 first flight
Post by: Mark Scarborough on November 27, 2009, 08:01:30 PM

well some people fly these for other than combat too,,  :-[
hey what can I say, its the stunt brain at work,,
I have heard some people use them for stunt trainers?

Title: Re: Gotcha 460 first flight
Post by: john e. holliday on November 28, 2009, 09:00:57 AM

I have a muffler on my Sweet Sweep.  It was the landing gear until I fabricated one. 

Title: Re: Gotcha 460 first flight
Post by: Dwayne on November 28, 2009, 02:30:59 PM

Thanks guys, no there is no muffler and on further inspection the engine mount has come lose so I didn't build it right. So I guess  have to do it again unless someone knows how to romove the wings with out trashing the 1/4" dowl holding the motor mount on. oh well live and learn.
Thanks

Title: Re: Gotcha 460 first flight (update)
Post by: john e. holliday on November 29, 2009, 01:18:01 PM

Thin CA should cure the problem or even some thinned down epoxy.

Title: Re: Gotcha 460 first flight (update)
Post by: dave siegler on November 29, 2009, 04:51:27 PM

Phil should pop in here any time and will have the best answer. 

What is loose the wood motor mounts from the nose block?  Or is the nose block loose?  Loose motor mounts can be cut out and redowled back in with lots of  epoxy.  All mine have metal bolt on mounts.

On my foamies, I needed a little tip weight.  I check mine by watching it glide and see if the wings are level.  Then I know the weight of the lines is accounted for.

The belcrank is on top of the wing, so if everything is aligned it might be slightly tip high (but very slightly).   

You may have a warp. Foamies do warp, you can try to use an iron and shrink it out.   Bend the TE to correct or add a tab. 

 

Title: Re: Gotcha 460 first flight (update)
Post by: phil c on November 30, 2009, 04:11:12 PM

The only way to tell what is wrong is to do some maneuvers.  If the outboard tip really is flying high the plane has a left roll and will tend to get light on inside loops. If that happens just twist the wing and re-iron the covering until it behaves the same for both inside and outside loops.

Give me a call if you are having problems with the wing/fuselage/motor mount joints.

Using external leadouts, either top or bottom of the wing generally has very little effect on things, as long as the leadout guides are close to the surface at the tip.