Skybench Osprey 900 - RC Groups
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Jan 10, 2017, 11:54 PM
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TScott1118's Avatar
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Skybench Osprey 900


This is Ray's Osprey 900 short kit. I started on it mid-November. I'm really happy with the kit, and it goes together very nicely.
I put the equivalent of a power 15 in the nose. The plans show spoilers and flaps, but I just built the flaps. My flaps are wider than those shown on the plans as I only plan to use them for landing.
The wingspan is 100".
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Jan 11, 2017, 12:37 AM
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buzzfly's Avatar
As always, your builds are quite beautiful.
Jan 11, 2017, 11:27 PM
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Thanks Mark!
Jan 12, 2017, 07:56 AM
My landing tape is too short.
p9o1r1sche's Avatar
Did you fill in the FG weave with epoxy before priming, or fill it with primer before painting?
Jan 12, 2017, 06:23 PM
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Quote:
Originally Posted by p9o1r1sche
Did you fill in the FG weave with epoxy before priming, or fill it with primer before painting?
I brushed on polycrylic mixed with talcum powder. Four coats sanding with 1500 wet sandpaper between coats.
Jan 13, 2017, 01:02 AM
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Originally Posted by TScott1118
I brushed on polycrylic mixed with talcum powder. Four coats sanding with 1500 wet sandpaper between coats.
That's my boy!
Jan 13, 2017, 11:11 PM
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I'm still struggling to get a really smooth finish when fiberglassing. So while it looks good in pictures, it has a few warts. Plus I painted in the garage and the paint didn't dry before the nighttime cold set in. So one spot is scaly. I think that was the cold.

I'm beginning to get those first toss full flying stab jitters.
Jan 14, 2017, 01:43 PM
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Quote:
Originally Posted by TScott1118

I'm beginning to get those first toss full flying stab jitters.
I know that feeling. The instructions might include information about locating a neutral elevator point. If not, measure up on the plans from the bottom of the fuse to the leading edge and trailing edge of the stab where it meets the fin, then replicate these marks on your plane. Go with that for an initial setting and you should be close enough.


-- the markster
Jan 14, 2017, 07:57 PM
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How did you retrofit the hooks into the wings?

I really don't like the tape method and would love to add the hooks if I can learn of a good method to do it on finished and covered wings.
Jan 15, 2017, 09:52 PM
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Quote:
Originally Posted by Harjit
How did you retrofit the hooks into the wings?

I really don't like the tape method and would love to add the hooks if I can learn of a good method to do it on finished and covered wings.
Harjit, just put a little block of 1/4" ply (or basswood or spruce) on the inside of the root rib, and that will give the hook something to screw into. I forgot to do it on this plane, so I cut a hole in the bottom sheeting to add the wood after the fact. So I can tell you it's easy to do after the wing is complete.
Jan 15, 2017, 10:06 PM
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And it's complete.
I'll take your advice on the stab incidence, Mark. Thanks.

It weighs 53oz ready to fly with a 2200 battery and 1 oz of noseweight to balance. Hopefully I can take the lead out as I move the CG back.

My power set up - 3s lipo, suppo power 15 equivalent, a 35 amp esc, and a 12x8.5 prop provides 330watts of umph. That oughta be plenty.
Feb 03, 2017, 11:07 PM
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Any flight reports, Tom?
Feb 03, 2017, 11:32 PM
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Quote:
Originally Posted by buzzfly
Any flight reports, Tom?
Due to bad weekend weather, no. Hopefully tomorrow!
Feb 07, 2017, 09:01 AM
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First Flight of the Osprey 900


Sunday brought springlike weather, so I packed up my Osprey and went to the local schoolyard.
I had to make a few adjustments to the flaps, and then it was time for a few hand tosses. A little down stab trim was all that it needed for a long flat glide.
So I throttled up and climbed to about 200'. There was a bit of a breeze, but it had no problem penetrating which surprised me as the airfoil is fairly thick.
Lift was scant, but I did manage several three to five minute flights. I took two batteries and limited my motor runs to two minutes per lipo which gave me I've an hour of stick time.
I have the CG on the spar and I plan to move it back a little next time just to see how it changes things.
Very happy with this sailplane!


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