Time for the Wilhelmson Rotary Canopy latch install. It’s been a long time coming. If you want one, here it is. This solves a lot of problems. Access from outside of the aircraft is via a 3/16 allen key. So if I get locked out I just need to find the nearest IKEA outlet. It needed to be outside my shortened custom designed stakes. I also needed a latch that wasn’t in the way of my enlarged throttle. It needed to be away from my intended ‘below the longerons’ window too. I needed to be able to place the mechanism exactly where I wanted it so it was not in the way of my left arm despite being in the vicinity.

Quite a list. This unit ticked all my boxes.

I bought it from Jack Wilhelmson quite a while ago but in all that time could not understand how it worked. Call me crazy but I thought I should know this before I installed it. Jack is a gentleman and and engineer. He made suggestions which didn’t help, but he tried which I appreciate. After all, I am only qualified as an eyeball engineer, not a real one. All I wanted was a video or some pictures of it working, no one on-line could help with that either. I made a test rig instead, that didn’t help much. In the end, I just blindly installed it per the instructions. It didn’t work 100% of course but by then, I was in problem solving mode knowing that I must be close.

Here’s the latch.

The instructions have you take it apart which is always fun.

This little nut comes out for now but its the one you eventually open the canopy from the outside with.

All set up per instructions.

I drilled where the instructions said knowing its only a small couple of holes initially so if I was wrong I could drill some more nearby without too many tears.

The metal plans latch I’d made two pictures ago didn’t quite work. So I made a dummy latch to try and find a position for the middle bolt that did work. The plans position certainly didn’t.

Yes I had a few goes at this. Candidate #3, plans was a no go. Test latch in the middle, #2, allowed me to find options. I though I needed a fatter latch in some places. I was wrong, things started to fall into place. So I made candidate #1. The only change I needed was to move that pivot point to the left. To be fair to the designer, I have separated the plans style latch to being a remote hook and handle, so I can fit my throttle in.  If I’d stayed as per plans it may have worked first time.

The next little issue was that I couldn’t open the three latches on the push rods enough due to the new latch bumping into that bolt on the oblong canopy push rod joiner. I solved that one with a countersunk machine screw instead of an AN3 bolt. Took a while, but we got there.

The latch was sort of working now! Its a bit strange still but magic forces seem to hold it closed despite the lack of a satisfying click.

This is the close position and it really does LOCK here. Oh another little snag was that this thing seems to be designed for where the plans door is. You glass up the door but you also have a nice indent there. I had to hack into the side quite a bit to allow the latch to sit flush. I’m not 100% happy with this and may add a clickbond female so I can secure the latch bracket firmly. I’ll consider this option later and after many happy hours of latch use during the next few months  of the build.

Another view inside the plane with the canopy locked. Of course when I went to drill it out for the proper countersunk longeron screws I hit a new snag. The rotary latch no longer closed because the latch was too close to the longerons now. A bit weird. I made a spacer and that fixed it but the spacer was too thick. I made another another at .060″ and this worked. There are more magic adjustments up and down as well as forward aft and the spacer then allowed those up/down to come into play for later fine tuning.

Here’s the cool part. It is easy to open the canopy from the outside when it is locked. I’ve positioned the latch just outside where the strakes go. If I went further forward it would limit where the window goes. Its always something. <grin>

Just more magic. I have a locking canopy what works off a common allen key. Please don’t tell anyone.