Canopy locking mechanisms
 

Hi All,

I wanted to change my canopy lock on my RV-4 canopy frame/skirts etc from the Vans supplied method which means you "pull back to lock" shut for flight to one that is forward to lock - previous experience has always been "forward to lock" and I would like to be consistent about it. Maybe not the biggest deal but its just something that concerns me.

I have worked out how I would use a quadrant attached to the handle to change the requisite angles of the locking rods that slide through the canopy frames and lock into the fuselage structure forward and aft. The back one will work fine using the existing hole in the canopy frame. The front one is more of a problem because of the angle it is now working at -i e it runs down at about 30-40 degrees if I want to get it locking the frame near the base. If I run it straight across it will be locking the frame about 8 inches above the base and at about 30 degrees off its travel in a horizontal plane, because of the curvature of the canopy base and skirt.

I know some others have also rebuilt this mechanism to a "forward to lock" system, so I'm interested to see how you did it. Any information will be useful - ts something for me to work on while locked down from the Coronavirus.

Many thanks

Chris

I'll shoot you a picture of mine later today. Forward to lock definitely seems more natural to me.

A picture of the dilemma would be helpful
 

If I understand the challenge, it is the steep angle the front rod approaches the instrument panel.One thing to consider is mounting a bullet shaped rod in a guide tube at the panel that is driven by the forward rod with a clevis type connection. This will allow automatic alignment both laterally and vertically as the forward rod moves through its arc, but the bullet stays square and centered with the hole in the panel.

My thoughts..
 

A lot of RV-4's have that conversion, but I built mine "per plans" with the Pull to Lock scenario. I also have the additional safety catch provided by VAN's. Its nearly impossible to loose the canopy, and requires a concerted effort to open against the springs . I recently flew an RV-4 back from Fla. for a friend that had the reversed Push-to-latch set-up, with no secondary safety latch. I was so nervous about it, I attached a short bungee I took along from the knob to the underside of the panel preventing me from blowing the canopy by accident. The forward lock also puts another "round ball" in the region of the throttle, something that in a busy cockpit could be pulled aft during decent...bye bye canopy...I embrace the original design(with safety latch), even know its opposite of the natural thought process.

Thanks for replies.

I don't want to do anything complicated; I take the point about the extra lock and the proximity of levers with balls on the end! Nevertheless, having to install a second lock because of the insecurity of the first seems counter-intuitive.

I'll sit and stare at it a while longer. I hadn't thought of the locking rod ina a guide tube articulated with a clevis. I quite like that.

Skysailor (or indeed anyone else who has made this change) - love to see a photo if you have time.

At least I have plenty of time to think about this and enact any change. going nowhere quickly.

Chris

The second lock..
 

Chris,
I would post pictures, but my computer firewall does not allow photo sharing links, so in short, the original design is not insufficient per say, as it has a spring that helps keep the latch rods engaged. The secondary safety latch is a very simple little blade hook that utilizes the existing pivot, and drops in a small slot on the Longeron cap. In the event you failed to pull the lock lever back, the secondary safety latch would be engaged . Only full forward travel of the lever would disengage that...complicated but simple!

Accidental release
 

Chris, the comment about bumping the knob if it is locked forward is a valid concern. My system is toggled over center in the locked position so any force to withdraw the bullet from the panel only intensifies the locking geometry. That said, a bump from shoulder or elbow vertically is a negative concern.

I would appreciate ideas for a ?backup? latch function that does what the bungee cord did, yet is elegantly simple and functional.

If you do this you can have a taxi position hole in the instrument panel an inch or two above the normal lock hole.

https://drive.google.com/open?id=1mB...iQRdM-_7wu1naK

Canopy latch
 

Canopy latch either direction works for me I'd be curious to see what the safety lock looks like

Safety Latch on VANs webstore
 

The safety latch is a stardard VANs part and the install is on my drawings.Its sold on their website as RV-4 Canopy Safety Latch" Bag 951" for a whopping $15.60. Small, simple and effective. Its standard in kits after about 1990.

Door latch
 

I am extreemly pleased with the Hendricks latch I put on my 4. Here is their website, you should take a look at this at least.

http://store-hendricksmfg-com.3dcart...ches_c_11.html

My Rocket came to me as a "forward to lock" but I further modified it to have a stout over center action as well as a warning light. The mod was amazingly simple and really amounted to little more than changing the fwd rod from a clevis to a rod end.

use of rod end
 

Some questions to Michael (Toolbuilder):
I assume the rod end was needed because the over center lock or is there another reason?
Did you use other rods than originaly specified to screw in the rod end?

Take a look at the Hendricks door latchs for the RV4. I put one on mine and love it, I also got the one you can lock with a key.
http://store-hendricksmfg-com.3dcart...ches_c_11.html

Here's a pic( I hope) of the Vans safety latch. Like Bill E. says simple and effective

Skip

Yes, to allow the handle to rotate through 180 degrees. A fork on the front rod won't work (double shear).

I changed the front rod to steel so I could weld in a threaded stud for the rod end and also a washer at the front guide location to act as a positive stop for the over center action. The rod end simply adjusts to set the tension.

Pull to lock
 

One consideration is that will the " pull to lock " if pilot is incapacitated in a mishap the backseater can put their left foot on the knob and push it forward a **** of a lot easier than trying to reach the" forward to close " knob and pull it back. Just my two cents Cheers. Stew