For flight-testing I've selected IKEA's 'GUNDE' pilot-seat and ejection system. The seat costs £9 here in the UK, though supplementary ejection-pack 'AARGH' costs an extra £90,000. Taking your nylon 20mm conduit cable-clamps, pitch these just inside of the IKEA-supplied plastic feet (which form a nice abutment).
With these saddle-clamps in place, locate the seat entirely centrally for reasons I've yet to fathom. Draw around the clamps with a sharpie or scribe, and remove so as to drill a 4mm hole through the depth of the centre-section. Avoid the use of pop-rivets at this stage if you value your life.
Park the frame against a garage wall and fasten using both washers and 'nyloc' nuts... for which you'll need a 7mm hex ring-spanner. An aid to this process is an off-cut of 20mm tubing that keeps the clamps aligned during fastening. It proved not to need a cross-head screwdriver on the other side, for reasons best known to the fastener. An easier alternative again however is to do this prior to fitment of the safety grilles.
There's a message here from the FAA inspectors following our build-process in lock-step:
We cannot believe that you seriously contemplate using a $12 chair from IKEA for the purposes of flight-testing. Are you unaware of the fact that Walmart do a camping chair for only $9.99, which INCLUDES drinks-holders?
