Q-500 Racing Discuss AMA 428, AMA 424, and any other variants of Quickie 500 racing

scat cat dihedral question

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Old 12-13-2008, 11:02 PM
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rideon67
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Default scat cat dihedral question

I'm building 2 replacements for a scat that folded the wings in a snap roll. The wings are 2 piece sheeted foam core which depend on a hardwood block and sheeting for strength. The way the cores are cut the wing halves must be joined after sheeting which makes adding carbon fiber difficult. Because two kits are being built at the same time it is possible to build the wings in one piece by using both sets of shucks if the dihedral is omitted. This way carbon fiber could be put in under the skin.

This design is a low wing that is a great sport flier if built with the dihedral and standard tail feathers (rudder). What would the effect of a flat wing be? My high wing Dominator has a straight wing and it flies OK, but not as responsive as the scat. Has anyone built a scat with flat wing? Thanks.
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Old 12-13-2008, 11:38 PM
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Default RE: scat cat dihedral question

i would be joining the wing halves with dihedral as per specs then add 2 layers of light glass cloth, forget the carbon. if you do this the same way [ pittbull construction ] your wing wont fold.
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Old 12-13-2008, 11:57 PM
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rideon67
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Default RE: scat cat dihedral question

That's how the one that folded was built. The wing joiner block is about 10" long. The last one folded outside this and had about a 3" wrap of glass cloth at the center that stayed intact. I'm thinking the wing needs strengthing for at least half of its span which would be a lot of glassing. I was hoping to save that. I'm running a piped webra 36 and the g forces are pretty big. I'm thinking 4 strips of carbon about 22" long. 2 on top and 2 on bottom.
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Old 12-14-2008, 12:59 AM
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Default RE: scat cat dihedral question

On the "Pit Bull" there are 3 layers of glass. The last one goes out past the landing gear blocks and is about 14" wide.

It sure won't hurt to add some carbon fiber. There is a flat piece on the bottom of the wing. There is another piece that is in a slot in the foam on the top of the wing.

You might also consider some harder wood on the top wing skins. This should be more resistive to compression seen on the top wing skin.
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Old 01-08-2009, 12:34 AM
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idigrc2
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Default RE: scat cat dihedral question

Here's a pic of the scat I scratched built off the original plans. The airfoil was thinned from the original and there is maybe a half inch of dihedral in the wing. No wing spar just a 6" strip of fiberglass around the middle. Plan lasted a season before the wing got a stress crack from the retracts and blew apart in flight. If you have a chop saw you can change the angle of the dihedral by triming the ends
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Old 01-08-2009, 03:10 AM
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Default RE: scat cat dihedral question

imagine if you applied a 12 inch set of glass to this wing. you would still be flying it. just love the engine and pipe combination very trainer like wouldn,t you say ? i won,t comment on the retracts.
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