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Slingsby T.50 Skylark 4

Let us all watch your new project progress.
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GeeW
Posts: 47
Joined: 18 Mar 2015, 22:49
Location: Bracknell

Re: Slingsby T.50 Skylark 4

Post by GeeW »

I hope that is not a water ballast tank thermometer that appears at the bottom of the instrument panel? :shock:

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B Sharp
Posts: 728
Joined: 19 Mar 2015, 17:18
Location: Perthshire

Re: Slingsby T.50 Skylark 4

Post by B Sharp »

Well spotted GW ! It was all part of a retro fit completed on the 35th February of next year.
Brian :D

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B Sharp
Posts: 728
Joined: 19 Mar 2015, 17:18
Location: Perthshire

Re: Slingsby T.50 Skylark 4

Post by B Sharp »

I have now dealt with the wing fixing problem. Mike Trew had originally detailed a hidden system constructed with plastic brackets on the underside of the wing and threaded plastic blocks bolted into the fuselage. Most of these off the shelf items no longer exist so I opted to adopt a similar system but using custom made metal brackets instead.
A custom metal bracket is screwed to the underside of the main spar. This has holes on it’s front face for 5mm “alan key” headed bolts” to pass through. A custom metal bracket is screwed to the internal structure of the fuselage. This also has corresponding holes in it’s front face which have been tapped for 5mm bolts. When the wing is in place the faces of the two brackets sit within 1mm of each other. The “alan key” headed bolts are inserted from the cockpit and screwed into place. It all seems tight and secure.
I have also spent some time creating the over-wing fairing which will eventually be glued to the wing. This will get some final sanding once the canopy glazing has been fixed to the canopy frame to provide a guide.
Brian. :)
Attachments
Wing Joiner bracket screwed into the fuselage.
Wing Joiner bracket screwed into the fuselage.
Wing Joiner bracket screwed to the wing.
Wing Joiner bracket screwed to the wing.
View from the cockpit with the wing screwed in place.
View from the cockpit with the wing screwed in place.
Over-wing fairing.
Over-wing fairing.

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B Sharp
Posts: 728
Joined: 19 Mar 2015, 17:18
Location: Perthshire

Re: Slingsby T.50 Skylark 4

Post by B Sharp »

I have now completed the second wing outer panel and finalised all the joiners. This afternoon I managed the first full assembly of the airframe and it appears to be pretty much Ok. In fact I am quite chuffed with the look of the glider at the moment. Also, it is very light! 8-) 8-) 8-)

I have also now cut the right aileron from the wing panel. The wing still feels quite ridged but the aileron is very floppy. I will continue to face it up in the hope that it gets a little stronger. :? :? :?
Brian.
Attachments
SL4_49.jpg
SL4_50.jpg
SL4_51.jpg

Jolly Roger
Posts: 414
Joined: 30 May 2015, 20:35
Location: Sutton Bank, North Yorkshire

Re: Slingsby T.50 Skylark 4

Post by Jolly Roger »

Looks lovely Brian. If you fancy chucking it off the hill the full-size first flew off... just drop in.

Probably worth covering it first though. :D

Keep posting - happy to watch your progress.

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RobbieB
Posts: 577
Joined: 07 Mar 2015, 22:22
Location: North West
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Re: Slingsby T.50 Skylark 4

Post by RobbieB »

Ah those Skylarks, don't you just love 'em.

Looks really nice Brian.

John Vella
Posts: 240
Joined: 20 Mar 2017, 22:09
Location: UK

Re: Slingsby T.50 Skylark 4

Post by John Vella »

Good build Brian. I hope it flies as well as the full-size. I have happy memories of the "Wooden Nimbus" ,with Phil my CFI flying his Skylark4 and me in my Discus scratching together in light conditions on Edge Hill. Regards John.

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B Sharp
Posts: 728
Joined: 19 Mar 2015, 17:18
Location: Perthshire

Re: Slingsby T.50 Skylark 4

Post by B Sharp »

Thanks Guys for the comments. It's not an aeroplane that I got to "fly back in the day" so I cant comment on it's performance good or bad. However as they say "if it looks right it will fly right" and I feel that this one "looks right". :) :) :)

Having just said that, I have faced up the aileron cut-out on the wing and it seems good and strong. However the aileron itself, after facing with 1/32 plywood, is still too bendy for my liking. The aileron is 1/2 inch thick, 1.5 inch chord and just over three feet long. Even with the horn mounted close to the centre of it's span I suspect that there will too much twist at either end when in flight. I am also worried about flutter when my flying gets "enthusiastic". I have ordered up some hard straight grain balsa and I will form up solid ailerons from that and see how they perform by comparison. I know that its not strictly scale but I would prefer a machine which handles well without too many limiting factors. :? :? :?

Brian

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chris williams
Posts: 1193
Joined: 10 Mar 2015, 10:50
Location: Blandford Dorset

Re: Slingsby T.50 Skylark 4

Post by chris williams »

Pin the aileron to the board, Brian, and add diagonals...works every time

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B Sharp
Posts: 728
Joined: 19 Mar 2015, 17:18
Location: Perthshire

Re: Slingsby T.50 Skylark 4

Post by B Sharp »

Unfortunately Chris I have already added the top and bottom capping strips so diagonals would be a bit of a problem. The structure is so long, narrow and fragile that I have no confidence that it will not twist in the air.
Brian. :(

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