While I was working on the canopy hinge, my buddy Andre worked on the canopy latch.  The torque tube is positioned and clamped in place.

Here you can see that the finger on the end of the latch penetrates the hole in the seat back bulkhead.  After ensuring everything was positioned properly, we marked the position of the holes in the bushing blocks with a #30 bit.

After match drilling the C-619 spacer (aluminum spacer between the plastic blocks), I reinstalled the center subpanel and used bolts placed loosely through the holes to keep everything aligned.

Here’s a closeup showing how the aluminum spacer is sandwiched between the two plastic blocks.  The spacer is the exact width of the hinge bracket on the canopy.

Finally, I reinstalled the top skin to pull everything into its final position.

I clamped all of the canopy hinge block components together and drilled #12 holes through the forward fuselage channels.

After these were drilled, I removed the center subpanel and installed the C-617 blocks using bolts through the newly drilled holes and then match drilled the 1/4″ hole.

I spent the rest of the evening preparing another hose order for Bonaco.  There will still be at least one more hose order after this containing the fuel lines from the servo to the spider and the oil lines from the accessory case to the oil cooler.

I started working on the canopy latch.  Instead of the latch included with the kit, I’m using the canopy latch from fairings-etc.com.  This will be perfectly flush on the outside of the plane instead of the protruding fingers of the stock latch.  The only disadvantage is the weight.  These are cut from 5/8″ thick aluminum stock instead of the 1/8″ thick stock used in the kit latch, so they’re quite a bit heavier.  I laid out a few lightening holes, but I may just drill holes part way through from the bottom side to remove weight without changing the appearance.

The quality of these as received is pretty marginal.  The cut edges are all very rough and will require quite a bit of hand work to smooth out.  Also, the predrilled holes are too large which makes for a sloppy fit around the pivot bolts.  I’m going to have to ream these holes out larger and fabricate some bushings to eliminate the slop.

The other problem with these latches is that the outer skin of the aircraft is used as the spring to keep the aft piece (on the left in the picture) engaged with the forward piece.  This seems like a pretty poor design as it will repeatedly flex the outer skin and could fatigue it over time. Fortunately, I knew this prior to purchasing the latch and ran across a good way to solve the problem on Roee Kalinsky’s site.

I double checked the measurements I made last night and found them spot on, so I got started cutting out the slots.  I used a unibit to remove most of the material.

I then spent a few minutes with the hand nibbler removing most of the rest of the material to just inside the lines I’d marked.

I then clamped a steel straight edge along the line I drew and filed down to the line.  The steel straight edge serves two purposes, it helps ensure that the filed edge is perfectly straight and it prevents filing past the line since the file basically stops cutting when it hits the straight edge.

After about 30 minutes of filing, the latch fits pretty well in the slots.  I had to round the corners of the latch pieces slightly since I didn’t want a sharp inside corner on the skins because that could lead to cracking.  At this point, the latch operates pretty well; good enough that I can go ahead and drill the attach angles to the skin.  Once the final position of the latch is defined, I’ll finish filing the edges to provide even clearance all around the latch.

I took a break from the canopy latch handle and went back to the latch itself.  I trimmed the lower ear as specified in the plans for weight savings.  After taking this picture, I used the touch-up paint that matches the powder coat to cover the bare metal.

Next, I drilled the bushing blocks out to full size and temporarily bolted the latch into place.

Finally for this evening, I fabricated the idler and linkage.  The upper hole in the idler will connect to a pushrod whose other end is attached to the canopy latch handle.  Here’s the mechanism in the latched position.

And here’s the mechanism in the unlatched position.

I laid out and drilled the holes on the attach angles.  I also put four layers of blue painters tape between the angles and the latch pieces.  These add about 0.018″ of clearance between the pieces to make room for the 0.016″ thick UHMW tape that will be installed in the completed assembly.

I then clamped the latch in place.

And backdrilled through the skins.  This is the opposite of the way the Van’s plans specify, but it ensures that the latch is perfectly centered in the slots and the holes are centered in the attach angles.

Finally, I fabricated the connecting rod that ties the latch handle to the idler.  I ended up needing to make mine about 1/8″ longer than the plans specify.  The tube has to be cut to length and then the ends tapped out to 1/4-28 for the rod-end hardware.

Here’s a closeup of the handle end.  You can see how I had to notch the upper attach angle for the rod-end.

With the handle in the closed position, you can see how the idler is pulled forward which pushes the latch finger into the slot on the bulkhead.

Here is the latch handle pulled back all the way.

With the latch handle pulled back, you can see how the idler is pushed back which pulls the latch finger forward.

I received some UHMW tape from Van’s yesterday, so I disassembled the latch and put pieces of tape between the attach angles and the latch handle pieces.  I then filed out the openings so that the handle has about 1/64″ clearance all around.  This required removing and installing the latch handle countless times to get the fit just right.  I still have a little work to do to get this where I want it, but it’s operating smoothly now.

I reassembled the subpanel along with the hinge blocks and clecoed on the top skin.

I drew a centerline down the aft tube on the canopy frame.  This will be used to ensure the holes drilled through the top skin will go into the center of the tube.

Several other builders have commented that some of the welds prevent the skins from laying down properly.  The instructions mention this, but a picture is much more clear.  Here you can see that the weld would push the skin up about 1/32″ or so.

30 seconds with the vixen file and the weld is nice and flush with the angle.

The instructions also mention that the flange needs to be filed square with the face of the forward channel through the center.  A few minutes with the vixen file also took care of this.  Sorry for the blurry picture.

I clecoed the skin to the forward channel of the canopy frame and drilled most of the aft tube (the one I drew the centerline on).  I’ve seen a number of other builders have a problem with these holes not lining up with the centerline, but mine was almost perfect.

I fit the canopy frame for the first time, but almost immediately I had an interference problem.  I couldn’t get the canopy frame far enough forward.  I had anticipated interference from the hinge spacers, and a quick check with a mirror confirmed that was the problem.

I pulled the spacers (which involved climbing under the subpanel and removing the hinge blocks which was a pain in the ass).  I trimmed 3/16″ off the back edge.

I reinstalled the hinge blocks and spacers and then reinstalled the canopy frame.  Another builder commented that using a strap helps pull the skin down tight.

That resolved the issue.  I now have almost 1/8″ clearance between the hinge arm and the spacer.  Do yourself a favor and cut at least 1/8″ off the back of these spacers from the dimension Van’s specifies.  It will save you a lot of headaches.

With the hinge spacer interference resolved, I could get the canopy skin almost all the way forward.  I’m still getting some interference somewhere because I can’t seem to get these skins any closer.  I have almost 1/32″ on the left side.

On the right though, I have almost 1/16″ gap.  I need to determine where the interference is so I can pull these skins tight.

I couldn’t find anything obviously preventing the canopy frame from moving farther forward, but I suspected the seal support flange.  I unclecoed the outboard portion of the canopy frame skin and sure enough the forward channel of the canopy frame was pressed firmly against the seal support flange.

A few minutes with the vixen file removed the interference and now the canopy frame could be moved far enough forward that the skins butt together.  The plans want you to put a 0.020″ spacer between the skins, but the fit isn’t perfectly tight along the whole joint.  Instead, I’m going to butt the skins tightly together and then file the canopy skin to create a uniform gap along the whole joint.

I put a couple of ratcheting straps on.  One is pulling the sides of the frame inward to ensure the frame is the correct width.  The other is pulling the frame down to ensure it’s tight against the fuselage.

I also use a couple of clamps to make sure the canopy frame wall pulled down tight.