Here's what I'm getting at: I've purchased two six-metre lengths of 1" x 1" x 1/16" angle alloy, cut into three equal lengths to fit the car. Back at the workshop the question is to whether we shall mount the safety grilles flush with the top-surface of our frame, or else level with the underside. For practical reasons the latter wins out.
Proceed by working with the long lengths arranged around the outside perimeter by clamping them in place and driving in five rivets: one at each end, one centred and two more centred again between the first three (and all done by eye). Take care not to locate the end-rivets too near the internal tube connector, which projects around two inches.
Next do the same with the internal long lengths, for which you will need to remove the bolts that secure the four cantilevers to the centre-section. Mark the location and drill a hole in the angle alloy to re-fit the bolt. If necessary mark up those rivet-heads that may be in the way with a touch of paint so as to make an impression, and drill an oversize hole in the angle-alloy to accommodate... it's what prototypes are there for. Only four rivets needed here as the bolt serves as the fifth.
Finally add the shorter lengths, using three rivets to secure. I have not mitred the join between long and short lengths of angle-alloy because (a) it wastes material and (b) I cannot be bothered. As a result the short lengths are a couple of inches shorter than you might have expected. Measure all lengths independently too, as they may vary just a little depending on how true the original rigging of the centre-section had been.
The net result however, as you can see, is four trays into which our safety grilles can be dropped tomorrow, which after all is another day. We will need an elevated cockpit as such times as eight motors are incorporated in X-8 configuration, though here we're building a utility quad for those 'low-riders' amongst us. Accordingly we can set it all on the level, and this is the safest and most practical way to do so.
