The Murphy Builders Site

OK, doors are installed, but I'm still waffling on what to do about a latching mechanism. The SR doors are built on a one inch square frame. At the aft center, you cut a 1/2 inch square hole through the tube for a piece of delrin that rides in a corresponding square tube. It has a spring in it to keep the latch closed. Probably similar to Rebel systems. etc. I've installed the delrin and tube that it slides in. That's where I stopped. The plans have a simple cable mechanism and pivoting flat latch. You open the door on the inside by pulling the cable. The outside by pulling on the flat latch. Simple and it works, unless you want to do something on the inside such as upholstery etc. I ordered a truck bed cap keyed latch with a cam, but was surprised at how heavy it was. They do have something made out of composite, but I'm getting tired of spending money. I don't want to spend a lot of time on this or reinvent the wheel. I'm inclined to just go with the plans. Simple and light weight. No lock. Convince me otherwise!

Hi Jerry
Glad you're making good progress.
I used the simple cable on the inside
I glued fabric to the foil that has air bubbles inside
Very cheap at home depot
Also I used chafe tape around the outside door frames because the door vibrates in flight and was wearing on the outside skin badly.
Hope the pic helps

Jerry, if you are planning to go on floats ever, you want a latch system that is easy to open. The cable system as designed by MAM works very well, and makes it easy to egress if you should ever find yourself upside down in the water.

I have seen some really bad latch implementations, where you had to reach back to the rear of the door to turn or pull a handle. That is a very unsafe, and wouldn't even want that in a wheels airplane.

Not sure if the top window latch is the same in the SR as with the Rebel, but if you only have one latch in the middle, might have an issue with the front pulling out at higher speeds. Some have moved the latch more to the front (which I would do if I was building again) or have added a second latch at the front. Since I did mine initially in the middle, I just added a velcro at the front to keep the window from pulling out. I just make sure to have it undone for take-off and landing.

Today, I made the latch for the passenger door based on advice from Fred Darnell. I used a 1 inch piece of soft aluminum angle on the inside, and bolted the outer handle hole to it with a nylon bushing. This allowed the handle to fold aft instead of forward as in the Murphy plans. I used a piece of case hardened steel (Bowden Cable) to connect the latch to the delrin sliding block. I will go forward with the 1/16 inch cable but had to order some nicopress sleeves. Fred had a good idea on an interior handle and I'll incorporate that as a pre-planned product improvement. In the meantime, the 1/16 inch cable will go forward to the next crossmember, a vertical 1 inch square tube, per the plans.

One of the issues that encouraged me to go in this direction was the way the Murphy supplied paddle handle was pre-drilled. The inner hole allowed no clearance from the aircraft skin or the doublers to install a bolt per the plans.