Is beauty only skin deep?

This weekend I’ve been getting on with the interior skinning of the enclosure. This is an important part of the build not only because you obviously need an interior surface to keep out the light and enclose the cockpit, but also because it imparts a greater degree of stiffness to the whole structure by filling in the gaps between the framework.

The material of choice for the inner skin is 6mm plywood. This is not particularly strong (you could punch through it without much difficulty, I suspect) but it is light and flexible and the strength it does have is lateral – it would be much harder to pull a piece of plywood apart from the ends than to break it by going through the face. I bought a few sheets of this in my last wood drop, and now it’s going into use.

The interior surface of the main bulkhead

My cutting tool of choice for the 6mm plywood is my Dremel circular saw attachment (see earlier posts). This has a maximum cutting depth of 6mm, so it’s perfect for doing long rip cuts on top of a supporting surface. It’s easy to hold and guide and unlike a ‘real’ circular saw, it’s not incredibly noisy and difficult to keep on line. Nevertheless, the cuts have been less than perfectly straight. Without a complex system of fences, it’s quite hard to get absolutely straight lines. This doesn’t really matter in the long run as long as they’re within certain tolerances – sanding and filling will do the job.

There are a few gaps here and there

I had already put a ceiling in place in the vestibule area as a proof of concept, so I was happy that my technique would work. I put in a further two pieces along a 45-degree angle to give a nice coped effect to the ceiling, making the interior more angular and closer to the round surfaces you’d get in a real cockpit.

Outside framing for the ceiling

Today I skinned the remainder of the right-hand size of the vestibule. This looked fairly straightforward, until I discovered that the a-frame wasn’t absolutely straight. It actually leans back slightly, and the rest of the frame is measured around, so rather than being a bug, this is actually a feature. Sort of.

Underside of the bulkhead - cool, huh?

I was thus required to cut the top and bottom panels specially, with a slight slope on the top and bottom edges, respectively. I also had to cut out a piece of the top panel to accomodate the bulkhead at the top. This took a couple of attempts to get right. I then remembered to pre-sink holes for the screws, which I had not done previously (and I will have to take out all the screws from the other panels and sink holes for them, before I get around to the fill-and-paint part of the job).

The rear is kinda messy, but will be covered up...

When I got to the bottom part of the frame, I came across the part where the a-frame goes from slanted to straight. In theory, therefore, I should have cut two panels to fit either side of the divide. In practice, I decided to take advantage of the flexibility of plywood, and put in a single panel which I carefully screwed down so that it curved across the divide, providing a nice curved surface at the base. I almost wish Id done more of this elsewhere <g>.

So, a few hours later, here I am, with a fully-skinned right-hand side. Of course, there’s much finishing to be done. All the various gaps and cracks need to be filled or sealed with either wood filler or silicone sealant, depending on the extent and nature of the gap. That comes later, though, in the finish-and-paint phase of the build.

The full (and slanted) glory that is the skin

I’m not skinning the left hand side of the vestibule now, for the obvious reason that this is the entrance point to the sim – there being no space behind the sim to put a standard door. I will eventually construct a door that looks pretty much like the right hand side, from the inside at least, and I will also put panels at the back – but this will likely be the last part of the construction.

Current state of play from the outside

Next up, then, is the beginnings of the footwells, where my feet – and the rudder pedals – will go. These will serve as the base for the MIP, too, so it’s an important part of the build.