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

[JimD]

So....even after I cautioned about this, no one said a word! You just let me put the servo in the wrong way! Output arm was on the wrong side!

Luckily, just needed to make a mirror image for the other side and that solved the problem.

[JimD]

Peter recommends the Spektrum A7050 thin-wing servo for the ailerons and elevators of the Swallow. These get mounted to the doors of the recessed mounting plates. 3/16" thick basswood worked well for the aileron mount. These servos have a plug-in lead so you will need to leave a gap for that. Also, leave enough space for the door to fit back into its recess. The bottom picture is the view from inside the wing so you can see the amount of space between the basswood servo mounts and the surround of the recess. Make sure that the slot for the output arm is oriented correctly for the aileron horn because the horn mounting slot is built into the aileron and would not be easily relocated (see picture above).

[JimD]

Time to flip the wing over and complete the bottom sheeting and cap strips. Also, the aileron servo hatch gets added.

First, the leading edge balsa gets sanded to the rib contour.



We used the hot iron technique to attach the bottom inner and outer panel plywood sheeting...really works well, I like it!!!



The aileron servo hatch support needs to be trimmed to fit the opening in the rib bay and it needs to be externally level with the cap strips and leading and trailing edge plywood sheeting.

[lenb]

Jim G.
Contact me if you are interested in a Swallow kit. I'm having 5 more produced for the spring and 3 are taken.
I'm the point of contact for Peter G's scale ships

860-395-8406

len

[JimD]

Span is 4.5 meters

Basically, following his retirement, Peter designed the Swallow for his wife Caroline. He has his own laser cutting equipment and was persuaded to cut out several "kits" for friends while he was at it. Same thing happened with his Smellyak tow plane.

If you are interested, maybe Len can put in a good word for you and twist Peter's arm to cut out another kit. Peter told us that his plan for retirement was to be able to design and build planes that he personally always wanted...not to create a business that would consume all of his time.

[jgallacher]

Beautiful build Jim. What is the span and where are the kits sold?
Jim G

[JimD]

We got the nose sheeting narrowed down to one last sliver.



Once the glue was dry we gave the sheeting a smooth sanding.



The last of the cap strips were attached to the top of the wing panel and allowed to dry overnight.



This morning, the weight bars were removed and the top sheeting was trimmed even with the leading edge and everything was given a smooth sanding.



One thing we noticed is that the wing bolt hole (just behind the wing rod tube) in wing rib W1 is not pre-drilled into the wing root doubler, the fuselage wing root rib, or the fuselage sides. We used the W1 rib from the unbuilt wing panel along with the wing spar tube and the anti-rotation pin to align things and then drilled holes for the wing bolts into each side.

[ARUP]

Post #12 shows how to put ply skin on a wing and without heat! I only did the LE but it could have been longer. The difficult part is the curved LE.

http://forum.scalesoaring.com/forum/aerotowing-slope-scale-soaring/scale-sailplanes/6911-1926-rrg-prufling-in-1-4-scale

[JimD]

We sanded a taper on both ends of the plywood sheeting so that the joint between the inner and outer sheeting would have a nice overlap.




The leading edge cap was attached so that the bottom edge rested against the work surface. This allowed for us to use the hot iron method for applying the plywood sheeting.






Glue was applied and spread evenly and the ribs/spar and sheeting then allowed to dry. The iron was set to highest setting.



Water was spritzed onto the plywood sheeting with a re-purposed eyeglass cleaner bottle and the iron was used to press the plywood down against the spar first, then out each rib and then on to the leading edge. Pretty easy, and we got a neat joint between the inner and outer sheeting.

[JimD]

Thanks for posting this...Excellent video tutorial!

The structure of the Swallow wing is very light weight, but as such, I don't think the pressure applied with the iron would be tolerated. Peter suggests attaching the sheeting at the spar and then flipping the wing over and gluing the sheeting out to the leading edge while supporting the sheeting against the workbench surface. This worked well for us, but it did require CA glue.

The sheeting kicked up very slightly along the back edge, so I did use the hot iron technique to get the sheeting nice and flat over the spar. This was an area where we could put significant downward pressure on the iron without fear of collapsing the underlying structure...and it worked like a charm!

The other neat thing in the video was tapering the edge of the plywood skins so as to create an overlapping seam instead of just a butt joint. This will be my preferred method from here forward! Simple, easy, and a much better way. Will be doing this where the inner and outer plywood skins meet on the Swallow.

[Stew2]

I thought I would pas this on. It is probably common knowledge, but the link below has a great set of videos on how to sheet with 1/32 plywood using water, an iron and heat activating PVA glue with an iron after it has dried, I also like how the technique releaves any residual stress in the sheeting which would otherwise contain forces that will want to warp the wing.

https://scalesoaring.co.uk/VINTAGE/HintsTips/Articles/Ply%20Panelling/Wing%20sheeting.html

[JimD]

Back to the nose sheeting...only one more section to go after this.



Back to the wing, time now to start wing sheeting. we elected to do this in stages in order to assure that the wing does not get a twist built into it. With the wing properly held to the flat work surface and the 3/32" shim under the trailing edge of the aileron section, the first section of sheeting was glued in place to just the spar and partially to the ribs. once set, the rest will be glued.
We started with the sheeting held tightly against the previously installed spoiler pocket sheeting and then applied a weight bar to hold the rest in place.

[Tango Juliet]

I need to pick up one of those cone shaped bits for my Dremel.

[JimD]

Now that the tow release mechanism is installed, the top sheeting can be finished out and then the nose cone blocks can be attached.



...and we made more balsa curls by adding the "V" taper to the rudder hinge line.







The shaft of the Robart Hinge Points taper toward the pivot, so we like to use the Dremel to enlarge the opening of each hole.

[ARUP]

Yes, +1 w Gunny! The release looks familiar! lol