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Old Sep 14, 2009, 11:12 PM
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Atomic Wedgee -It Flies

Flew the Wedgee a few weeks ago at Byron in 20-25 knots and it behaved itself really well, and fast.
Clocked it out of a dive at 115 MPH without any ballast.

Really Happy !!!

Also had a fly at Beechmont a few days later in less than 5 knots and was worried it wouldn't stay up because there was not enough lift to keep other things up. So just on dark I gave it a chuck and it had no problem staying up.

Since then I've been waiting for a big day to DS it but no luck.

I've now moulded a full carbon one that will come out at about 700grams and about 920 ballasted. Popped it out of the mould last night. There is about 24 hrs put into it so far but when it pops straight out of the mould looking like this, it's worth it!!

The carbon one is soooo stiff and looks good too.
Have to build like mad to finish this to take to Manilla next week, maiden this weekend would be nice.



I've just added some comments and photos from the maiden flight here http://www.rcgroups.com/forums/showthread.php?t=1111538
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Last edited by Iwanufly; Sep 28, 2009 at 10:48 PM. Reason: Added comments and photos of maiden flight
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Old Sep 16, 2009, 09:06 PM
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Absolutely !!!!
Yuri.
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Old Sep 27, 2009, 11:59 PM
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I've added some colour so I can see it and it weighs 800g unballasted.

Maidened it at Manilla Slope Fest on Thursday, launching it off and pulled the nose cone off as I threw it . OHHH SHI*%
So I quickly whipped around for a quick landing. Luckily everything was OK so I taped the nose on and chucked it again, right into a big patch of sink.. OHHH SHI*% again!!
There is no where to put it down on the front side in one piece, so after about 1 minute of thinking it's gone, I found some good air and recovered.

Still a bit nose heavy but OK for now.

This wedgee is a bit heavier than the last one and definatly faster. You could not take your eyes off it for a second.

I scared myself a few times with some fast low passes that must have been around 140 MPH (no radar ).

On Sunday we walked into the DS spot at Manilla but after seing the rocks and trees on the backside landing area I chickened out and decided to leave it's maiden DS for another day.
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Old Dec 08, 2009, 06:02 PM
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Thats a great looking wing. How is its flight programme going?
I'm also guessing that you CNC'd the plugs.
Did you analyse the wing/planform to arrive at the shape?
Anyway to my eyes - it looks right analysis or not.

cheers John FAE(Frustrated Aero Enginneer)
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Old Dec 08, 2009, 10:02 PM
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Hi John,
I've now had plenty of laps with the wedgee's but have only managed 143MPH so far.
I'm now building number 3 for a spare and working on a split fin to slow it down to land.
Hoping to get lots more flight time over the christmas break.
I only used basic theory for the design like aspect ratio and sweep according to the airfoil designers comments, but mainly it was if it looks good it will fly good approach. It seemed to work because it performs brilliantly, better than expected.
The plugs were printed in a 3D printer.

Cheers
Shane
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Old Dec 09, 2009, 06:54 AM
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Shane,
Thanks for the info.
3d printing-thats keeping up with Technology. Did you use powder or polymer systems(I have just done a crash course on Wikipedia - hadn't heard of it) and how does the plug stack up dimensionally and with respect to durability? Any special problems with Epoxy - release agents etc?
Sounds like a great alternative to CNC - is it more expensive?
Pardon the Q's - i was involved in another project which was CNC'd and cost around 10K for the 4m wing plugs( top,bottom left and right) in machining grade foam.
If you haven't already tried them Profili as a XFOIL driver and XFLR5 are both useful programs.
It looks like it needs either flaps(bit difficult with FW's) or a small parachute to slow it down, or just a drag brake?

Cheers mate and good flying.
JOHN
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Old Dec 09, 2009, 07:09 AM
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Shane,

Missed your mention of a split fin. This may be hard to lock solid for high speed. As a suggestion - possibly 2 rotating drag brakes forming a large section of the back of the fin - one above the other? One opens to the left and one to the right to equalize drag. Pivots at around 25-30% of their MGC to help them stay balanced and over centre direct drives to lock them out at speed.

Just my 2c worth.

This system(only going one way though-75% down, 25% up) was used on the wings of gliders - as a trailing edge brake/flap with a low pitching moment and lots of drag - as much down as possible. They weren't very big.
Effective but back then they were driven by belcranks and pushrods with a tendency for slop.

cheers
John
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