Slingsby T-37 Skylark ~ 1/3-scale model by Peter Goldsmith (Build Thread by JimD)

[Ed DeRossi]

Jim, what wood did you use on the leading edge of the ailerons? What thickness?

[JimD]

Hi Ed,

We used a piece of 1/8" thick balsa cut from a sheet of 1/8" included in my kit...I think this is how the production kits are assembled as well.

[Ed DeRossi]

Thanks Jim. I didn't have that sheet in my kit but I have some in the shop. I want to also thank you for the build thread. It saves me a lot of the think time so I can spend more time gluing. This is a great kit and a lot of fun to build, especially because it goes together so fast. Peter did a wonderful job on the design and construction techniques. I can't wait to start on the Chmelak after I finish this one.

[JimD]

So far this year I've built the 40% Schweizer 1-26, the Swallow, the Skylark, and I am finishing up the Smellyak and a Sapphire! 😜

[Pgoldsmith]

Thanks Ed. In some of my earlier kits I actually laser cut the TE, however we found that for the best fit to just have the customer manufacture one from the sheet supplied. Now if only I had included the sheet it would have worked out...😳

[Ed DeRossi]

So far this year Jim I crashed that many !!

[JimD]

Now that the wings are completed, time to install the ailerons. Hinges are made from the covering material which, in this case, is UltraCote. We cut 3/4" wide strips of UltraCote and ironed a strip along the top front edge of the aileron.



The aileron is carefully placed in position and the UltraCote is ironed down to the wing side of the hinge line.





The aileron is flipped over onto the top of the wing and a second 3/4" wide strip of UltraCote is ironed in place straddling the hinge line.





Then the aileron is flipped back into its neutral position and the sealing iron is used to insure a good bond between the UltraCote hinge and the wing surface.



Now install the G10 aileron control horn and make the pushrod from a DuBro 2-56 threaded rod with clevis using a Z-bend for the connection to the servo arm.

[JimD]

Returning to the center main wing section, the spoilers are installed. First, sand a slight taper along the front and back edges of the spoiler blades so they can open and close without binding. Use music wire to make stirrups for the spoiler hold downs (we used 0.032" wire) 5mm wide and 18-19mm long. align the holes in the spoiler blade with the output arm of the servo making sure that the arm will capture the stirrup as it closes. Glue these in place so that the bottom of the stirrup extends out 12mm from the spoiler surface. File the wire stubs level with the outside surface of the spoiler blade.

Cover the tops and sides with covering material and drop the spoiler blades into their pockets. You will probably note that they drop noticeably below the wing surface. We used some scrap 1/32" plywood as a spacer to bring the spoiler blades up level with the wing surface. We also used pieces of the 1/32" plywood as spacers at each end of the spoiler blades to center them in the pocket.

Check to make sure there is adequate space all the way around the spoiler blade before making the hinge.



Hinge is made from a 3/4" wide strip of UltraCote applied similarly to the aileron hinge except, only apply to the top surface.



Here is the spoiler half open, note the servo arm and stirrup.



Here the spoiler is fully open. The springiness of the hinge combined with the air load force will push the spoiler closed (servo only drives the spoiler open and is otherwise not connected to the spoiler blade). As the spoiler closes, the servo arm captures the stirrup and holds the spoiler tightly closed. You will need to fine tune your servo end points to get this just right. It is also a good idea to slow the servo motion down so the spoilers open and close a bit slower.

[JimD]

Tailored Pilots offers a pilot bust that is inexpensive, light weight, but needs to be painted. We used Tamiya Acrylic Paint (available from Swiss1 at the Model Box or Horizon Hobby) to paint our pilot and the canopy frame. The canopy was cut to fit the canopy frame and glued on using Deluxe Materials Canopy Glue

( again available from Swiss1 at the Model Box or Horizon Hobby).

[JimD]

Launch Gear Dolly

Wheels are DuBro Light Weight 4-1/2" foam filled style wheels. Dowel in launch carriage fits into hole drilled in the bottom of the keel slightly ahead of the CG. Weight of plane keeps the launch dolly in place until the plane lifts off, then the launch dolly falls away.

[Swiss1]

Is there a Brass Tube on the Skid to accept the dowel, as it may oval out the hole over time I would think!

[JimD]

No brass tube, just a hole in the plywood skid...may need a tube later, but best to have a loose fit.

[JimD]

Some final trim additions that hopefully capture some essence of the retro design.

[JimD]

Maiden flight success!!!

Used launch dolly and did ROG from my grass runway. Takeoff was straight and true with only a short ground run until lift off. Flight was beautiful, absolutely no trim changes needed. Skylark has excellent L/D and spoilers are very effective...Peter has designed a beautiful model that is easy to fall in love with...Thank You Peter!!!

[JimD]

AUW for this model is 12lbs 11oz

CG range on plan is 100-110mm back from leading edge...is model is balanced at 105mm

At this point, I would not change a thing...now for more stick time! 😎😎😎😎😎😎

[Pgoldsmith]

Congrats Jimbo, beautiful work.

[lenb]

Congratulations Jim.

Another fine example of craftsmanship

[Tom]

Wow! Very nice.....might just have to get one of those! Good job Jim!

[Swiss1]

Nice stuff as usual Jim, dare we call that Dolly's "Dolly"

Jeremy
SCCAAA TT TN

[JimD]

Dolly launching from launch dolly...