PT-20 Build – The Wings

The plans say this wing will build itself – that’s closer to true than I might have imagined! It quite literally took more time to pop the die-cut ribs out of their sheets and clean them up along with the leading and trailing edges than it did to build BOTH halves of this wing.

PT-20 Wing - removing from plans

PT-20 Wing – removing from plans

In the picture above you can see the construction is very straightforward… once you get the center spar pinned down and the rib webbing pressed into it, the ribs just slide into the notches in the web. Next, press fit the top spar onto the web, trapping the ribs. Align the trailing edge and ribs, glue. Repeat for the leading edge. Just make sure you keep everything flat as you go! Got it all lined up? CA does the rest.

PT-20 Wing Centerline Mating Surfaces

PT-20 Wing Centerline Mating Surfaces

Because I am building the “B” sport wing, I used the dihedral gauge to mark the proper angle and then used a razor saw to cut the LE, TE and Center spars/webbing along that mark – keeping in mind that the cut (front to back) needed to be 90 degrees to these parts. You’ll need to get this correct the first time because you don’t get much of a 2nd chance with it. You can see, I got pretty close – hopefully some careful sanding will get these closer to perfect.

PT-20 Wing - mock join

PT-20 Wing – before joining

PT-20 Build – The Fuselage

Fuselage Right 3/4

Fuselage Right 3/4

Construction of the fuselage has been straight forward for the most part. The only things that presented difficulties were the aforementioned warped parts (which I cut replacements for) that needed to be sanded and shaped a bit to get a good fit. The instructions ask that you drill 3/16″ holes in some of the bulkheads/formers so that they can have the pushrod guide tubes passed through them.

Pushrod guide tubes

Pushrod guide tubes

Some of these bulkheads were plywood and were easy to drill the holes in, some of them, however, were balsa and did not take a drill bit very well. As a result, one of these broke and I ended up cutting a replacement from plywood – just to save the grief of breaking another one.

Bottom view of Fuselage

Bottom view of Fuselage

Fuselage Interior & Servo Tray

Fuselage Interior & Servo Tray

So far, I am pleased with the resultsĀ  and have just a few more items to complete on the fuselage before moving on to the wing assembly. This project is moving along well and I will be posting the wing build and photos soon.

PT-20 Build – Horizontal / Vertical Control Surfaces

The first steps in this project are building the horizontal and vertical tail surfaces. This is a simple process; only requiring gluing two pre-cut balsa sheets together to form the horizontal and vertical stabilizers. I sanded smooth, rounded leading edges on the stabilizers. In the photos of the horizontal assembly, you can see that I have hinged (but not glued) the elevator on to the stabilizer.

Horizontal Stab and Elevator

Horizontal Stab and Elevator

Horizontal and Vertical Tail Surfaces

Horizontal and Vertical Tail Surfaces

These assemblies have been set aside and I will begin construction of the fuselage next. I’ll post some updates and pictures of it soon.

PT-20 Build – Intro

PT-20 Build - Box Art

PT-20 Build – Box Art

The subject of this build is the Great Planes PT-20 Kit. I haven’t built a kit in a couple of years – so this seemed a simple enough subject to get back to building with. I intend to convert this from glow to electric during the build and will elect to assemble with the sport ‘B’ wing option from the plans.

This kit has been in my possession for quite some time – it moved to Arizona with me about 5 years ago and had been in storage back in Georgia for a while too. Like many who enjoy building kits, I bought this one knowing that I didn’t have time for it ‘right now’ but that – someday – it would eventually get built. Because it had been in storage for so long, I did find some of the die-cut sheets bowed or warped in the box (shame on me.) Those that could be straightened were, and the few parts that were twisted just a bit too much, I made replacements cut from balsa stock so the build could proceed.

I do not intend to get into a lot of detail – regurgitating the assembly manual – but I will post progress photos and any technical issues I encounter and how I resolved them.

Flying soon at an airfield near you.