• Administrator
  •  
    Before your membership becomes valid, you will receive an email that must be answered.
    Please check your spam folder or this email.
     

Slingsby Kestrel 19

B Sharp

Re: Slingsby Kestrel 19

Post by B Sharp »

I have now had a close look at the rear of the wing that has surface damaged just in front of the flap and aileron. There is an internal balsa sub spar about 10mm forward of the hinge lines for the control surfaces. This is reinforced with a layer of carbon fibre bandage connecting the upper and lower surfaces. The area between this sub spar and the leading edges of the flying surfaces is hollow to allow the surfaces to rotate into the wing when moving up and down.

This sub spar appears to be totally intact and most of the surface deformation lies in the surfaces above and to the rear of the sub spar and is therefore essentially cosmetic. If I tried to reinforce the inside of this hollow area it is likely that the smooth movement of the flaps and ailerons would be affected so I have left it alone. I have however drilled a series of 1mm holes through the carbon reinforcing along the mid-point of the sub spar and dribbled thin cyano into the holes in order to “harden up” the balsa behind (just in case).
I will have to live with the slight buckling of the upper surface because I will know that it is there. Most folks will never notice it. :roll:

While dealing with the wings I also rubbed back the red paintwork on each wing tip back to the original white gel coat. It has now been primed and awaits a new coat of paint.
Brian. :)
Attachments
Upper surface damage is cosmetic. I will live with it.
Upper surface damage is cosmetic. I will live with it.
Wing tips rubbed back and ready for paint.
Wing tips rubbed back and ready for paint.
B Sharp

Re: Slingsby Kestrel 19

Post by B Sharp »

There was a bit more progress today with the Kestrel. The fuselage was masked off, cleaned, primed and then sprayed with Halfords rattle can of Appliance Gloss White using one mist coat followed by two good flow coats. I managed to do this outside in the good weather we are having which allowed it to dry quite quickly. I then carefully moved it into the workshop and hung it from the ceiling where it will dry properly and harden before I start to mask it off for the colour. I also dropped in to see my local model shop owner who is going to cut the vinyl markings for me.
Brian. :)
Attachments
Watching paint dry!
Watching paint dry!
Jolly Roger
Posts: 573
Joined: 30 May 2015, 20:35
Location: Sutton Bank, North Yorkshire

Re: Slingsby Kestrel 19

Post by Jolly Roger »

It’s coming on really well Brian. Hope you avoided the usual pitfalls with spraying: runs, pinholes, falling off your chair... :D

We were going to pop in and see you on our way from Edinburgh to Skye on Tuesday but were too tight for time. Sorry we’re not around when you pass ours next week. Hope you get the Kestrel finished in time.

Rog
User avatar
Max Wright
Posts: 198
Joined: 10 Mar 2020, 19:57
Location: Clayton Bay South Australia

Re: Slingsby Kestrel 19

Post by Max Wright »

You're doing a great job of it, Brian.

We're kindred spirits - I'm doing the same thing with an A-14 - although not as speedy as you. ;)
Max
B Sharp

Re: Slingsby Kestrel 19

Post by B Sharp »

All pitfalls avoided Rog. Sorry you can't drop by. However will get that canopy to you next weekend.
Thanks for the nice comments Max, I just can't bear to right off a good aeroplane.
Brian. :)
B Sharp

Re: Slingsby Kestrel 19

Post by B Sharp »

The paint is now dry and I have now been able to reattach the rudder and to hook up the pull-pull linkage between the rudder and the rudder servo which sits just behind the retract system.
I have been able to reconstruct the carrier for the flight battery and hot glue it into place. The receiver has been reinstalled, plugged up and tested. The most difficult aspect of this has been to tidy up the rats nest of wires so that they don’t get in the road of the retractable undercarriage.
The little guy had become a bit dishevelled in the crash and rather detached from his seat and the rest of the cockpit interior. He is now back to normal and happily (or perhaps not) awaiting his next flight. Finally the canopy was cleaned up and re-polished before fitting back into place.
The wings are also nearing completion. The servos have been checked and are performing fine. All wires and plugs have been checked for integrity. Clevises, servo horns and control surface horns have been checked and are operating with the least possible minimum of slop. The last task was to re-seat the hatch covers using clear tape.
The next task will be to do a full assembly and then re-balance the model. That will have to wait till next week cause “I’m going flying this weekend”.
Brian. :D :D :D
Attachments
Rudder pull-pull linkage installed.
Rudder pull-pull linkage installed.
Flight battery reinstalled in its carrier.
Flight battery reinstalled in its carrier.
Receiver back in place and wiring tidied.
Receiver back in place and wiring tidied.
Little Guy back in his home.
Little Guy back in his home.
Canopy in place.
Canopy in place.
Wing servos checked out and covers applied.
Wing servos checked out and covers applied.
john greenfield
Posts: 497
Joined: 18 Mar 2015, 07:52
Contact:

Re: Slingsby Kestrel 19

Post by john greenfield »

Brian

" Going flying this weekend" ?

Are you coming to Buckminster?

AEB
AEB = Aeronautical Energiser Bunny (with thanks to CW)
B Sharp

Re: Slingsby Kestrel 19

Post by B Sharp »

Yes John, I'm packing the car as we speak.
See you all tomorrow.
Brian. :D
B Sharp

Re: Slingsby Kestrel 19

Post by B Sharp »

Having now recovered from a whole lot of flying this last weekend this morning was balancing morning. I got the Kestrel fully assembled for the first time and checked that all the controls were working and in the correct direction and volume. In the early stages of the repair I saw that I had at one stage marked a range of CG positions on the wing root and I had noted their positions at the start of the repair. A quick check on my CG calculator indicated the correct position with a static margin of 10 came right in the middle of the marked range. A safe static margin of 15 came at the front of the marked range. I decided to go with the safe option and with that set up on the balancer I was able to calculate that I needed and additional 40gm of weight in the nose. I am really pleased with this as I expected to require a lot more bearing in mind the repairs to the tail end. I will carry out the first flights and may remove that weight for fine trimming.
Tomorrow is looking possible for the test flights – fingers crossed!
Brian. :)
Attachments
Ready for the test flights.
Ready for the test flights.
044.jpg
045.jpg
Jolly Roger
Posts: 573
Joined: 30 May 2015, 20:35
Location: Sutton Bank, North Yorkshire

Re: Slingsby Kestrel 19

Post by Jolly Roger »

That looks gorgeous Brian. Love the blue trim.

It’s nice when an accident gives you the opportunity to refurbish a model and make it tidier than ever, fixing all those little scrapes and dents our models inevitably accumulate, and adding in all those tweaks you’ve been meaning to do for years. Fixing rather than flinging is also good for the planet! Brian Sharp = global warrior. :D
Post Reply