18-05-2010, 04:21 PM
Kieran dropped by with my white covering on sunday night so it was out with the knife last night. I chopped all the holes, making those on the fuse a bit bigger and rounding all the corners to keep maximum strength.
Original flying weight without the battery = 1760g
I've subtracted 66g of balsa from behind the balance point. 46g came from the stabiliser and tail fin! = 1694g
The result is that the balance point has moved about 40mm forward on the wing. this should allow me to drop a couple of batteries.
I'm hoping I can drop 4x the weight from the nose to let the balance point move back to 30% chord = 1694g - 4x66g = 1430g. That's an 18% weight loss but I'm still nowhere near the biggest loser!
.
I did notice a dent near the tail which occurred about 3 sessions ago is now structurally relevant so I'll stick a little beam back in there to re-join that corner.
My next step is to drill holes in all the beams in the stabiliser and tail fin. I'd like to get to 100g cut out of the fram but I'm afraid that I'll start hurting strength before I get there.
Original flying weight without the battery = 1760g
I've subtracted 66g of balsa from behind the balance point. 46g came from the stabiliser and tail fin! = 1694g
The result is that the balance point has moved about 40mm forward on the wing. this should allow me to drop a couple of batteries.
I'm hoping I can drop 4x the weight from the nose to let the balance point move back to 30% chord = 1694g - 4x66g = 1430g. That's an 18% weight loss but I'm still nowhere near the biggest loser!
.I did notice a dent near the tail which occurred about 3 sessions ago is now structurally relevant so I'll stick a little beam back in there to re-join that corner.
My next step is to drill holes in all the beams in the stabiliser and tail fin. I'd like to get to 100g cut out of the fram but I'm afraid that I'll start hurting strength before I get there.
Drew
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Built-up
Balsa: Commercial: Depron:
Great Planes PT-20 (modified) HK Hawk 80 Index 3
Indoor Thingy Skyartec Cessna 182
Katana X lite (in construction) UM SU-26 12"WS Shoestring (Plantraco)
HK Extra 260
and a Fox chuck glider converted to RC
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