Tweaking the frame

(On a brief aside – WordPress is normally a great blogging system, way better than Blogger where I started off, but every so often it goes a bit wrong and eats my copy. Thus what appears below has been re-typed, badly, from memory. WordPress admins, take note and sort it out!)

Today was a bits and pieces day on the project. I spent the morning cleaning up the build room a little, getting rid of offcuts and bits of wood and hoovering up all the sawdust. This takes a lot longer than you think because sawdust takes up a suprising volume and there was several weeks’ worth to clear. So a few empties of the dust hopper later, I was nice and tidy. Well, as tidy as the build room ever gets.

The first thing I did was take out the window posts and move them a few mm back, so that there will be an overhang above and below them. This will accomodate the structure I’m putting in place to ‘fill in’ the posts – I’m experimenting with hard foam and pipe insulation for this, more in a later post. I’m also going to round off the edges with my Dremel router kit and put in grooves for the windows, but this will be at a later date.

The window posts were moved back a few millimeters

Next job after the clean-up was to cover over a few more holes with 6mm plywood. This involved cutting a few odd-shaped pieces, a feat easily achieved with the Dremel circular saw attachment. I’ve discovered that I can cut decent straight lines with this now, even without a fence. If only it could handle slightly thicker sheet: 12mm would be ideal. Ah well, that’s a dream for another day.

The skinning process has become quite routine now; cut the piece, locate it in place, clamp it, use the counter-sink bit to sink holes for the screws, and then pop in 9mm screws which anchor the wood very well. I have enough 6mm ply left to do the left-hand side of the vestibule – AKA the door, for which I now have a plan – but that’s about it. Time to order some more, so I can put a frame up at the rear of the enclosure, and then put up a back wall. Fingers crossed I can get that done this week.

Various complex shapes needed to be cut for the skin

Having done all that, and with a nice clean and empy enclosure, I tried fitting in a chair to see what the right position for the pilot’s seat would be. I found a position that was nice and snug – it’s going to be a tight fit whatever I do, with the total cockpit width a mere 1.8m, that’s about the same as a LearJet 45 or similar light jet – but I found that my legs were fouling on the supporting posts that hold up the frame at the front. I fretted about this for a while, and considered moving the seating position further right, but this would have contracted the width available for the pedestal such that putting in a two-lever throttle, let alone the four-lever that I’m planning, would be impossible.

The approximate seating position for the pilot

In the end, I figured an adjustment of the frame itself would be in order. I removed the supporting post on the left hand side, cut a 10-degree bevel into the top and bottom, added a t-shaped shim to make up for the length I had thus removed, and put it back in place, now at a 10-degree slant. This moves the base of the post well away from my legs and provides much more clearance for the footwells.

The newly-slanted post...

...compared with the old, straight one

I now need to repeat this procedure for the right-hand side, then I can look to begin framing work on the footwells themselves. The slanted posts will make this slightly more complicated, but not that much (yet another reason to be glad I bought a mitre saw capable of making compound cuts!).

Later on tonight I will do some sanding and filling work – gives me something to do after the power-tool deadline at 6pm (I like to keep the neighbours friendly). Then more framing work tomorrow.