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Re: Slingsby T.50 Skylark 4

Posted: 27 Nov 2018, 08:56
by VinceC
Very smooth

Re: Slingsby T.50 Skylark 4

Posted: 28 Nov 2018, 14:22
by B Sharp
My timber order has arrived and wing building has been able to proceed. The centre section of the wing is now complete and sanded to shape. The airbrakes open fully and close down and lock in place. I still have to create the faring that fits over the centre of the wing to fare it into place with the fuselage. That will probably have to be tackled next. :?
While I was waiting on the arrival of my timber I spent a little time on the instrument panel. I am not after total scale accuracy, I just wanted something that looked reasonably like the full size. An hour or so with my camera and photoshop produced a respectable replica.
Brian. :)

Re: Slingsby T.50 Skylark 4

Posted: 28 Nov 2018, 18:37
by GeeW
I hope that is not a water ballast tank thermometer that appears at the bottom of the instrument panel? :shock:

Re: Slingsby T.50 Skylark 4

Posted: 28 Nov 2018, 23:31
by B Sharp
Well spotted GW ! It was all part of a retro fit completed on the 35th February of next year.
Brian :D

Re: Slingsby T.50 Skylark 4

Posted: 02 Dec 2018, 13:25
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. :)

Re: Slingsby T.50 Skylark 4

Posted: 14 Dec 2018, 15:31
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.

Re: Slingsby T.50 Skylark 4

Posted: 14 Dec 2018, 21:43
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.

Re: Slingsby T.50 Skylark 4

Posted: 14 Dec 2018, 23:05
by RobbieB
Ah those Skylarks, don't you just love 'em.

Looks really nice Brian.

Re: Slingsby T.50 Skylark 4

Posted: 15 Dec 2018, 10:33
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.

Re: Slingsby T.50 Skylark 4

Posted: 15 Dec 2018, 18:21
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