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Re: Slingsby T.50 Skylark 4

Posted: 30 Jan 2019, 08:05
by Stuart Ward
Looking forward to seeing it in the air in May, Brian

Stu

Re: Slingsby T.50 Skylark 4

Posted: 30 Jan 2019, 11:31
by roo Hawkins
Looking really nice Brian

Re: Slingsby T.50 Skylark 4

Posted: 30 Jan 2019, 20:24
by B Sharp
Thanks guys
Brian . :)

Re: Slingsby T.50 Skylark 4

Posted: 27 Feb 2019, 17:43
by B Sharp
I have now returned from a month sunning myself on a rock in the Atlantic and at last I can report further progress on the Skylark.
This afternoon I have installed the receiver and all the fuselage servos as well as the wiring harness. In the photos you will see the receiver mounted up at the top with the elevator and rudder servos mounted below. The servo lying on its side in the bottom of the fuselage is the aerotow release servo. The two white coloured tubes in front of the receiver channel the twin aerials upwards in hopefully the optimum position for good reception. I have now to find a suitable spot for the switch before I locate the battery in a cosy little space in the nose.
Brian. :)

Re: Slingsby T.50 Skylark 4

Posted: 27 Feb 2019, 17:54
by StephenB
Soon be airborne :D

Re: Slingsby T.50 Skylark 4

Posted: 27 Feb 2019, 22:20
by RobbieB
B Sharp wrote:
27 Feb 2019, 17:43
'I have now returned from a month sunning myself on a rock in the Atlantic......................'
Ye Gods Brian, how did you cope with the trauma of a months dust settlement in the workshop when you got back?

Re: Slingsby T.50 Skylark 4

Posted: 28 Feb 2019, 20:27
by B Sharp
Robbie, I just had to man-up and get out my feather duster.
Brian. :D

Re: Slingsby T.50 Skylark 4

Posted: 01 Mar 2019, 14:32
by B Sharp
Today I have managed to erect the Skylark in it’s semi- complete state for the first time. It all went together quite nicely and I think it looks smart.
A session on the balancing rig saw me setting up C/G locations at 86mm, 92mm and 96mm back from the leading edge at the centre section. This equate to static margins of 15%, 12.5% and 10% respectively. I first added lead to the nose to get the C/G at 96mm back (10%) and then added two other lumps which will bring the C/G to 92mm (12%) and then 86mm (15%). After first flight I hope to be able to remove these two additional lumps to achieve the trim that I desire.
I still have control surface checks to carry out and some programming on the Tx before the maiden but we are nearly there.
Brian. :) :) :) :) :)

Re: Slingsby T.50 Skylark 4

Posted: 01 Mar 2019, 16:59
by B Sharp
Thanks, but not so fast Cliff.
I had another look at the calculated C/G locations and was a little concerned that they were located a bit further aft than I expected. I checked the advertised location on the plan and that worked out at 25% of the root chord. (a bit too far forward for my liking) I then calculated the 15% static margin C/G position and that worked out at 39% of the root chord. (a bit too aft for my liking) I have now opted to go for a 33.3% root chord C/G position and work from there.
This is the second time that my C/G calculation softwear has given me a C/G location which is too far aft for reasonable stability. The last time was on my MU28 glider and that made for a very exciting first flight. I know I have flown gliders in the past with the C/G back at 40% - 43% root chord but these were competition thermal soarers which are a very different animal to a scale glider. Experience tells me that 33% is a safe starting point and I can work the C/G back (or forward) from there.
Brian. :x :oops: :cry: :roll:

Re: Slingsby T.50 Skylark 4

Posted: 01 Mar 2019, 17:51
by Andrew Ray
Crikey, I haven't been on here for a while and shocked to see I have missed the build, I need to go back to the beginning and catch up!

Beautiful job Brian, of one of my favourite gliders.