Is the great planes CG machine worth the money?
08-03-2005, 11:10 PM
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Is the great planes CG machine worth the money?
I've been having a hard time setting the proper CG on these foam birds. It seems like being off just a hair really make a huge difference. I saw theis CG machine by Great Planes and was wondering if its a worthwhile investment.
08-04-2005, 01:50 PM
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RE: Is the great planes CG machine worth the money?
I think so, I bought one! But seriously, you need SOMETHING more precise than your fingertips. You can make one out of a couple of pencils and a block of wood, or buy one, but the CG Machine just makes it painless. It's pretty accurate, too.
Steve
Steve
08-04-2005, 07:15 PM
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RE: Is the great planes CG machine worth the money?
I made one with a slab of hobby wood and two dowels but I was just wondering if I'd get better results with the CG machine. Do you have to balance upside down like that or is it just for low wing birds? I'm trying to balance a Mountain Models Magpie.
08-04-2005, 07:56 PM
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RE: Is the great planes CG machine worth the money?
The CG machine isn't a necessity, but it is neat!
Two dowels with pencil erasers at the tips works as well.
But aren't as neat.
Low wings are typically balanced inverted to get the c.g. below the points of contact on the plane.
Otherwise it tries to turn over.
Two dowels with pencil erasers at the tips works as well.
But aren't as neat.
Low wings are typically balanced inverted to get the c.g. below the points of contact on the plane.
Otherwise it tries to turn over.
08-04-2005, 09:16 PM
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RE: Is the great planes CG machine worth the money?
The pencils in a block of wood thing works but the beauty of the CG machine is the adjustability of the width and the big pads are nice so you don't damage covering.. I really like mine but would get it mail order - the LHS likely will rip you off on it!
08-04-2005, 09:51 PM
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RE: Is the great planes CG machine worth the money?
Whats the deal with the erasers? Are you talking about the pointy tip ones? Is that just to get more precision/accuracy or as a cushion to avoid damage to the plane? How do you guys get lateral balance? It seemed like as little as 1/32 of an inch difference and my Magpie was flopping left and flopping right with no consistency on which way it flopped. It would also seem that I would have to dead on where I place the midline of the plane. I guess thats where the pointy erasers would help. Is there a better way to get lateral balance? Being new to this I had no idea how dead on I'd have to set the CG with these foam planes. That and being sure not to reverse the rudder by mistake which lead to a direct impact with my garage door! What a sickening thud that was.
Thanks guys!
Thanks guys!
08-05-2005, 07:30 AM
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RE: Is the great planes CG machine worth the money?
The erasers keep the plane from slipping as well as the posts from damaging the plane if it is heavy enough.
I use that technique for micro-flight planes but greatly prefer the GP CG Machine for parkflyers to .90-size glow conversions. The foam pads keep the plane from slipping, the construction is very strong, and, the measurements with the built-in rulers are repeatable.
I use that technique for micro-flight planes but greatly prefer the GP CG Machine for parkflyers to .90-size glow conversions. The foam pads keep the plane from slipping, the construction is very strong, and, the measurements with the built-in rulers are repeatable.
