Slingsby T-45 Swallow ~ 1/3-scale Kit by Peter Goldsmith (Build thread by JimD)

[Tango Juliet]

Slick work Jim! You're literally "flying" along on this build! Merry Christmas!

[JimD]

With the top wing sheeting in place, the cap strips were added to the inboard section.



Then we moved on to the outboard section and added the sheeting.





Then the outboard cap strips were added to finish out the top of the wing.



Using the balsa sub-leading edge as a crutch to support the ribs while the top sheeting was being applied worked out great! We were able to attach the sheeting without the need for a lot of overhang which will make trimming and sanding this edge much quicker and easier.

[ARUP]

+1 w Gunny! What's really great about this method is that the wood won't swell with the glue then shrink back once the glue dries because the glue is already dry! This eliminates the 'starved horse' appearance to frame work especially if using balsa sheeting. Also, you can use your iron to 'pre-curve' the ply so that is lays with less stress.

[gunny11]

That's neat Jim. Nice job!

[JimD]

After doing the two upper and two lower sections of wing sheeting we are more confident about how to size them. Basically, we cut them just 5mm oversize this time. The 48" x 1-1/2" aluminum angle makes a good straight edge to cut against.




Apply glue to both surfaces and spread out into a nice thin layer. Wait until the white turns clear and then use the hot iron and water spritzer to apply to the framework. Very slick!



The balsa leading edge worked perfectly. Allowed plenty of down pressure with the hot iron to apply the sheeting.

[JimD]

Next, we added the top trailing edge sheeting along the aileron hinge line. The hot iron technique was employed here as well...really like this process!

First, the trailing edge balsa strip was sanded to the rib contour.



Then glue was smeared onto both sides of the pieces to be joined and allowed to dry (white glue turns clear as it dries).



We added this piece of wood to support the inboard edge of the plywood skin.

[JimD]

The top spar was dropped into place and then we moved to the leading edge. The leading edge is in two thicknesses, the first gets added here and sanded to the contour of the ribs. The wing sheeting then glues to this piece. Then the sheeting is sanded flush with this piece and the second thickness is added as a cap and sanded to the contour of the airfoil.

We learned to use a hot iron technique for the wing sheeting that really works slick, but on the first wing, the leading edge was not supported adequately on the inboard section so we could not use the hot iron to push down on the sheeting at the leading edge. Instead, we had to flip the wing over and glue the sheeting from the underside.

This time, we made a modification to the leading edge cap so we can use the hot iron Technique on both the inner and outer sheeting sections. The leading edge balsa pieces were tall enough to work on the outboard section so we used what came in the kit. For the inboard section, we custom cut some 1/8" balsa that would sit on the work surface and be tall enough to extend up to the top of the ribs.





The spoiler mounting plate was installed noting the proper orientation in the rib slots.




Then the sheeting mask was added over the spoiler bay. Note that the very thin edge of this mask needs to be flush with the edge of the spar.

[JimD]

Next step is to install the 8-32 blind nut for the wing bolt attachment. We shaped a piece of 1/4" plywood for this task.









The top trailing edge sheeting is prepared by taping the parts together, bending the parts along the tape "hinge" line and applying slow set CA. The parts are then laid flat and the excess glue is wiped away leaving a nice joint. The tips of the ribs were lightly sanded to length and height, then the top sheeting was glued into place. Push pins and weight bar were used to keep the sheeting tight down against the ribs and bottom trailing edge sheeting.

[JimD]

Okay, break is over!

Now we can install the wing rod tube. First it needs to be cut to length and the outside scuffed with sandpaper to insure a good bond with the glue. The wing rod does not go all the way to the ends of these tubes (which is on purpose for load distribution) so we made a plywood tab that inserts into the end of the tube to keep the rod from going all the way into one side and then being short in the other side.

[Tango Juliet]

<3 Awe! Sounds good to me!

[JimD]

I'm anxious to move on to the next step, but the the inspectors are on break!

[JimD]

The ribs are undercambered, so shims are used to keep the bottom skin in contact with the bottom of each rib.
The trailing edge of each rib is held to the work surface with a stick pin.



Weights are applied to keep everything flat on the board.




The sub-leading edge square spruce needs to be made up out of three pieces. 1-1/4" scarf joints were used to join these pieces,



The outer partial ribs sit on a 3/32" shim to keep them properly aligned. the balsa trailing edge piece is glued to the angled back side of the ribs and a builder's triangle was used to check the rib position.




These triangles are not in the design, but adding them made me happy. Figure the wings can use the extra 0.01 oz. of weight!




Now we go on to add the square spruce sub-leading edge piece. Again the builder's triangle was used to check alignment of each rib.





Everything looks straight, so weights were applied while the glue sets.

[JimD]

Okay...the plan was to frame up the Swallow while I was waiting for my wing sheeting for the 2-33 to arrive. I promised Gunny that I would get back to the 2-33 by Christmas, so here we go racing to the finish line.

Getting the parts staged and ready to glue.





Time to start gluing starting at the root and moving toward the tip the laser cut shear ribs provide the correct spacing as we go along.



T-pins are used at intervals along the spar to keeps things in line.



We used some of the shear webs to check the spacing of the ribs at the trailing edge.



Rib position is marked and then ready to glue.

[JimD]

With a little light sanding, the servo mount is level with the plywood skins and rib caps.



Time now to start on the right wing and finish up this build. Thought I would point out a few of my techniques. First, the scribe line on my workbench to align the spar.



***Note that the root rib is NOT perpendicular to the spar line like the other ribs. It is angled to follow the taper of the fuselage...look carefully at the plan.***





The wing spars are joined .



All of the wing parts are gathered to start the build process.



All that remains in the kit box are the wing skins, wing tube and rod, and canopy. This kit contains everything, all of the wood necessary to build the model. This is not a short kit!

[Sinkhappens86]

Been there, done that Jim!