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Here’s how Allyson and I set up to lock our Legacy’s canopy. 

First, we purchased this Medeco high security cam lock with these specifications:

This Medeco Cam Lock can be ordered from the RA-Lock Company of Cedar Hill, Texas  (800.777.6310).  The lock is $23.25, the cam is $0.59, and the keys are $1.75 each. We placed the cam lock just behind the latch handle assembly.  This allows us to hide the key hole behind the latch handle when in the normal latch handle position.

With the canopy latch handle in its normal aft trailing position, trace its outline onto the fuselage skin with a marker pen. Draw a horizontal line down the center. Measure two inches from the latch handle body edge and mark the center of the hole for the lock. Drill a *” hole for the cam lock at this location. This hole is big enough for the body but not the head of the lock.  Place the lock in this hole with the head against the fuselage skin and draw a circle around the head.  Grind away the outer skin of the fuselage to this line so that the cam lock rests flush with the outer skin.  De-core about a half inch into the fuselage skin around the lock head.  This area will eventually be filled with epoxy/flox mixture for final bonding.

We built a strong fuselage housing for the lock out of 1/4" thick phenolic. The body of the lock has two flat sides that need to be firmly against phenolic sheet to ensure that the entire lock housing can not be forced to rotate. The phenolic housing sides are basically one inch square pieces and the flanges are 45 deg triangles with one inch sides. 

The lock head face should be bonded in flush with the fuselage skin. Tape over the key hole to ensure no epoxy/flox enters during bonding. We put the fuselage on its left side for this so that gravity was more helpful and duct-taped a piece of wood against the hole on the outside to provide a platform to rest the lock on and ensure it was perfectly flush with the fuselage skin. 

Before bonding it all in, hold the lock with the cam in position to ensure that the rotational orientation for locked and unlocked positions is correct and that the cam has been bent to the correct shape.  We hammered the cam out straight and then bent it about two inches from the attached end to get the right geometry to block the canopy latch torque tube.  The key hole slot should be approximately vertical and at the bottom for the locked position and horizontal and on the left side for the unlocked position.

Bond everything in place with an epoxy/flox mixture. Be sure to tape over everything you don’t want epoxy on.

We’re pretty happy with this solution.  It’s simple, light weight, and the key hole doesn’t show.

If you have further questions don't hesitate to ask us,
Valin and Allyson Thorn

I have incorporated two modifications to my Legacy that Valin Thorn posted on the LML; one which slightly raises the canopy when the canopy handle is opened, and the other which hides a lock behind the canopy handle. Both are elegant improvements to the Legacy's canopy system. However, I want to let readers know that I felt the need to modify the locking system. This is a result of playing an "avionics theft" on my own Legacy. Following the "prove it to me" approach, I tried to break into my Legacy with the canopy locked by wrenching down hard on the canopy handle. Don'tget me wrong, this was not some casual attempt to see if the canopy was locked, I really tried hard and there are still marks in my hand where the canopy handle dug into my flesh. Thieves won't care if they break something on your airplane. Well I did break something and it was the endof the lock tumbler where the striker is attached. My analysis of the failure concludes that the geometry of the system allows the canopy latching system to apply a force on the striker which applies a torque to the lock tumbler that the lock is not designed to take. Consequently the lock failed by the striker rounding off the tumbler.

Now I have to say that I would not put a lock on my Legacy unless it was hidden so relocating the lock was not an option (also it was already bonded in). As a result I noted that the best solution was to put the striker in tension on the tumbler with no torque. I recalled the solution Leighton M. used on John Halle's Legacy, which was to build a catch on the canopy torque tube off the existing weldments. I built a *" thick aluminum catch and mounted it between the weldments using 3 each #6 screws in double shear and bent the spare striker I purchased (it was a cheap .89 cent investment) to engage the catch. Playing avionics thief again I tried to break into my Legacy with the new lock. Maybe I am a masochist (and I have the bloody palms to prove it), but now I know I'll be replacing a shattered canopy instead of replacing a $25 lock and some soon-to-be-out-dated avionics. If I recall correctly, I have more time into building my canopy than any other part of my plane…… this lock idea really worth it?

Jim Thomas
L2K #166

In addition to Valin's solution, I?ll offer up another that I am using on my Legacy.

I guess I'm young and from the electronicsage, and probably a little spoiled by my gizmos. Therefore, I decided I wanted a keyless entry and lock. The above images shows what I came up with.

I built a base out of prepreg under the handle behind the seat. I have a latch that I bought from Aircraft Spruce that I modified to attach a door lock actuator to. This latch is spring loaded, and its plunger lines up with one of the holes in the canopy handle. It is also tapered, so it is self locking. Push the handle all the way down, and it locks when the plunger goes through one of the lightening holes in the handle. Hit the keyless or remote switch to unlock. There will be a remote pull cable just in case, but it will be well hidden.

Any questions, feel free to ask,
Shannon Knoepflein

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