Canopy work has officially started. Another major sub-project in the build of an RV airplane.
First task to achieve is installing the roll bar on the fuselage canopy decks. this is a steel bar which comes pre-brend and is supposed to protect the passengers in case of a crash where the aircraft starts rolling over.
After a lot of test fitting and measuring as per detail A in DWG42 plan, I drilled 2 the pilot holes in the top canopy decks. You have to use a rivet on the side skin as a reference and measure the front position of the roll bar from there. Then you measure the location for the AN4 and AN3 bolt that attach the roll bar to the upper canopy deck.
These are actually quite critical. The longeron lays underneath and you want to make sure you don't drill in the horizontal vertex of the longeron !
After inspection with a mirror, I think I'm located ok. My measurements were a tad more than in the plans. That may be the gauge of the paint and primer in between parts.
Next the manual tells you to bend the rollbar so that it fits within 7/32 inch from the side edge of the F721B canopy decks.
the manual says: "it can be adjusted quite easily by hooking one end behind something and pulling (to make it wider) or by putting one end on the floor and leaning on the other end (to make it narrower). Go Sloooowly. it's easy to do too much".
Well I can tell you, the guy who wrote that part of the manual must be a practicle joker.
I did try to lean on that one end to make it narrower. I pushed so hard that I got a muscle fracture under my rib and couldn't move for days.
I was going "slooooowly" for days. But the damned bar wouldn't move a fraction of an inch.
In the picture below, you see what I ended up doing. I squeezed the roll bar between two walls and some wood blocks and put a car jack in between.
It took a lot of force to get it to move a little. The difficult thing here is knowing how far you went on your last attempt and trying to go a bit more on the next.
After 5 or 6 times I got to move it a bit and it fitted well on the fuselage.
Next issue I'm scratching my head around is this tilt on one end of the rollbar. I tried to squeeze and twist the bar to get this straightened up but there 's no way it will move.
I will most probably end up by shimming one end if required or pulling it on when it's bolted down. I'll wait and see how the rollbar bow positions against the canopy frame so I'm leaving at this for now.
Here's a shot from above with the roll bar installed.
