Canopy Release Mechanism

I'm working my way through the canopy hinge setup.  It's slow going, mostly because the instructions are especially vague (and wrong) here. There are a number of steps that the instructions say to take now that contradict instructions earlier in the build of the forward fuselage.  These are just order of operations kinds of instructions, but doing things in a backwards order can mean the difference between a few minutes or a few hours.  For example, earlier the instructions said to rivet certain parts together, but now they proudly say that you can do XYZ easily since you haven't riveted those parts together yet.  That means either getting creative or undoing previous build to accomplish new tasks.  There are also pieces that I now see in the plans will need multiple large holes laid out and drilled in them, as well as nutplates put in place.  If the plans actually showed those holes or indicated measurements for them, it would have been a 5 minute task earlier in the build before parts were riveted together.  Now that the subpanel is riveted together in places, using a dremel to make these pass through holes for the canopy release is going to be a real chore.  A few measurements would be all that was needed to make it easy.  There's nothing though - just a realization that you have to chop your way through a few ribs and mount some parts on a riveted piece by seeing the completed drawing.  I guess they figure you can't actually put things together without doing it, so why bother calling it out or providing something as silly as measurements.

I wasn't super happy with one of the UHMW hinge blocks I made yesterday because I accidentally wallowed out the 1/4" hole a bit (the one that a pin goes through and secures the canopy connection).  I have extra material, so I remade that block and finished up match drilling both blocks to the subpanel ribs.  In order to drill the holes into the short ribs in the center portion of the subpanel, I put the skin back on and clecoed everything together to locate the ribs in the correct place.  Then I snuck underneath the skin and match drilled all of the holes through to the inner short rib.

Once everything was drilled, I took the skin off and temporarily bolted the blocks and spacers in place.  I'll eventually have to take it all out to rivet the whole forward fuselage structure together, but I think I can put that off for a bit yet.

The plans have a canopy release mechanism that is designed to allow you to jettison the canopy in flight (although nobody has every done that).  I'll do like most builders do - modify the design so that the release mechanism is still there, but not have it accessible from the instrument panel.  Given that the RV9 isn't aerobatic and I don't plan on flying with a parachute, I don't see any reason I'd ever be inclined to get rid of the canopy in flight.  I could simplify things and get rid of the mechanism entirely, but I've been told that if the day ever comes when I need to fix the canopy or do a lot of work behind the panel, it's really nice to be able to easily pop the pins and pull the canopy off.

Step one of the release mechanism is to make another UHMW block that a pivot goes through (see DWG 47).

Two steel tubes connect the center pivot point to the latch pins that go through the hinge on each side.  Making the tubes took a long time, so I only got one done today.  Holes are drilled in each end for clevis pins, then slots are cut (different sizes) to allow for the attachments.

Just for kicks, I put the canopy frame in place for a little motivation.  Based on how rough this frame is manufactured, I'm not looking forward to working with it.  I think it's going to be a bear to fit.

Canopy Hinge Blocks

It's been a while, but back at it!  I'm still waiting on a weather window for painting the interior, so I'm working my way through anything I can that doesn't require the aft cabin structure to be riveted in.  Next up is the hinge and attach mechanism for the canopy.  I'm sure they're sitting in a corner somewhere, but for the life of me I can't find the big UHMW blocks that came with the kit.  Thankfully I have the big block of UHMW that I purchased for the canopy latch modification, and it's the correct thickness.  I cut out blocks based on the plans dimensions and laid out the reference holes and drilled them on the drill press. Then I clamped them to the subpanel ribs (I had to take out the center subpanel section) and match drilled them to the ribs.

With the blocks and other thinner UHMW blocks drilled, I cut out and drilled the thick aluminum spacer/stop that goes between them.  I put the center subpanel section back in place, because the short ribs need to be match drilled to the blocks.  The short ribs can't be drilled as-is though, because they flop all over the place without the top skin holding them.  I'll cleco the skin back on to locate and hold the ribs for drilling.

 

Canopy Latch (5)

On the right side, the latch cable sets much higher than on the left.  The majority of the cable is already covered by the box in front of the seat brace.  I made a very simple standoff that attaches with the same screw that holds the seat back brace in place.  I haven't decided if I want to leave it as-is or box the rear portion of the cable in like I did on the left side.  I enclosed the left side because the cable sets lower and could be snagged by baggage, but I don't think that's as likely on the right side.  The only reason to enclose the right side would be for aesthetics.

The cable loops behind the baggage compartment bulkhead.  I'll just fasten it to the vertical rib to keep it from flopping around.