Chapter 18/22 – CAD Attack!

As has been evident many times before in this build, there is often layer upon layer of interdependencies that drive design changes (aka “mods”).  This very point became evident after I received my GNS-480 —and after I placed it in just about the only place it could go in my panel— when I realized that my EZ Rotary Canopy Latch from Jack Wilhelmson was just not going to fit.  And believe me, for the price I paid and the beauty and quality of Jack’s latch, it was not something I chucked aside in a momentary flight of fancy for something else!

At the time I remembered that both Bill Allen and Mike Bowden had rather unusual canopy latches, somewhat similar in style and appearance, and both of which I had seen at the Rough River fly-ins.

Well, through Alaska Long-EZ builder, Brian Ashton, I was linked up with Mike Bowden… who graciously gave me a very thorough run-down of the dimensions on his canopy latch. These conversations took place almost a year ago.  

Well, today I finally got around to plugging in all the known dimensions and extrapolating a few of the others to draw up Mike’s canopy latch in CAD.  The one significant mod I made is that I added a triangular pivot plate to the canopy latch arm which will allow a forward reaching pivot arm to manipulate the forward canopy hook.  If you’ve seen Mike’s Long-EZ than you know he has no need for one of these since he has a permanently attached windscreen portion on his canopy (like an F-104 Starfighter).

The shot above is a somewhat straight-on view of what you’d see in the cockpit.  The one below would be an upward view of the latch from the pilot seat area.

This is an outboard view of the canopy latch, shown with the 4 mounting screws that will secure it in place on the fuselage sidewall.

Here’s another outboard view, but here I’ve highlighted (blue rectangle) the exterior handle part of the canopy latch that will be visible from outside the aircraft.

And a snazzed up version of the canopy latch.  As I’ve mentioned over the past few weeks, I plan to machine the majority of these CAD-drawn components using CNC once I get down to North Carolina and settled in.  That being said, I should also note that I’ve been quite sick this week, so I’ve been doing some CAD work to pass the time (when I haven’t been passed out!).

With the canopy latch design and CAD drawing pretty much finalized, I then set my sights on the Instrument Panel.  I don’t have the exact dimensions on-hand since my project is down south, but I can always easily tweak those numbers later.  In addition, I simply started out by placing and “cutting out” the holes for the major panel avionics and instruments.  As time goes on I’ll tweak this drawing to account for switches, circuit breakers, etc.

Besides, a little birdie told me that if our schedules sync up that I may just be able to get this panel plasma cut (vs CNC’ing it), which would save quite a bit of time (wink, wink)!

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