Base assembly

At the Easter weekend, with my ear back to something resembling normal and my will to live renewed, I set about building the new base for the sim. This was before my weight concerns reared their ugly head and hence I was building with MDF as originally planned.

The base is a simple structure. The frame is constructed of pine softwood batons, 44m x 70mm x 2400mm. Oriented short-side-up, these give a vertical void of 70mm under the deck, which is enough for wiring and the rudder pedal assembly. A typical structure for a base would be a cross-hatch frame, with beams going in at right-angles to each other and with joints cut at the appropriate places to allow them to cross. This is typical drywall / stud wall framing, for example. As it turned out, due to a cock-up at B&Q, I didn’t have enough of the right size timber for a cross-hatch frame large enough for my purposes. Since getting the timber to my house had been a bit of a mission (this was before I discovered that unlike B&Q, Wickes have a decent delivery service) I decided to try something slightly different.

In the end, I settled for a simple arrangement of six timber beams laid across the floor at roughly 300mm spacing. This mimics the construction of a building floor, where floor joists cross the room in one direction and the floorboards are laid on top of them cross-ways. In my case, instead of floorboards we had MDF panels, but the principle is the same. This is also much easier to build. The downside is that the frame itself has no real structural integrity (other than that conferred by the MDF / plywood panels and the screws that hold them down), but since there will be no force trying to pull the frame members apart, merely force pressing down through the timbers and onto the floor to spread the total load, this isn’t a problem.

The frame ensures that the widest unsupported length of panel is about 275mm, which the 18mm MDF I was using is more than strong enough to take a man’s weight over. This is what it looked like when I stopped work over Easter:

Each MDF panel is screwed to the frame in eight places, ensuring it stays flat and even. At this point I noted that the floor in the middle of the room was bowed and there was a gap (only about 5mm, but enough to notice) under the frame at the mid-point of the floor. This set me off worrying about overall weight issues and hence my last post.

Having decided to abandon the MDF, I set about procuring plywood, discovering that Wickes has a decent delivery service and will deliver wood direct to the customer. I bought a bunch of plywood panels and some pine batons, and these arrived the next Saturday.

I spent the Saturday morning, while I was waiting for the wood to arrive, disassembling the old MDF console and pedestal. Given how many hours of work I had put into these I was fairly gutted to have to do this, but the weight issue is a clear one and in many ways I can regard these as my prototypes, my learning experience.

With this done and the room cleared, I could then return to the base build. I took up the old MDF panels and put down new 18mm plywood panels, ending up with a final base structure that looks like this:

The base is 2.4m long by 1.8m wide, which is large enough for the enclosure I am planning which will be around the same dimensions as a LearJet cockpit. The panel colouring, BTW, is entirely co-incidental; Wickes happened to send me four dark panels and two light ones (plywood comes as-is, pretty much) and I arranged them in the most aesthetically pleasing way.

With the base out of the way, my attention turns to the basic enclosure frame. This will need a fair bit of designing and cannot just be dived into – the cuts need to be worked out and done accurately. I’m considering buying a mitre saw for this purpose, though in the end I might just use a mitre jig and my reciprocating saw. Time is up for this weekend, though, so it’ll be a few days before I can get to this…