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Last night John installed the pilot’s side retractable step. We made this out of an aluminum tube with a solid aluminum rod inside – others have had trouble with hollow rods bending. I cut a slot lengthwise in the tube, with a notch in one end forming a detent.

The detent was John’s idea, and solves an important problem. When extended, you expect general wear and tear usage, so a bit of play or rattle isn’t a big deal. When retracted, you want it to be in EXACTLY one position, with no rattle, so the end sits flush against the fuselage side, and can’t rotate or vibrate (which would create drag).

To address this, rather than having a detent for the retracted position, we’ll use a spring that holds it in the closed position. The slot for the knob is perfectly shaped at that end, so it can be in only one precise position while retracted (that is, there’s no play in the slot at that end; there is along the rest of the length to prevent binding). The springs make it easy to retract the step, too – just rotate it past the detent, and let go. The spring does the rest. We’ll test it out after the BID and UNI wraps over the tube cure, then install the passenger’s side.

After hemming and hawing over any last items I might want to put in there (we now have two battery cables, ground and supply, two brake lines, an alternator field disconnect wire, and several pull ropes/wires for later installations), I finally sealed up the rear heat duct. This takes some doing, because it’s two plies of BID and seven more to beef up the seat belt attach point, but I got it all worked out in a few hours and the installation looked good this morning.