I realized that the spring on the lever was effectively duplicating the one in the micro-switch so in the best traditions of trying to keep things simple I tried to build a version which doesn't bother using it. The revised lever arrangement is a bit simpler but it takes a little bit of adjustment to:-
- get the springing in the lever right,
- the micro-switch to change correctly as the catch handle is pulled and also
- the screw which fastens the attachment to the lever not to foul the micro-switch on the lever.
The resulting modules fasten on the levers quite well. (though I realized after I took this picture I'd got the one on the end with the mounting bracket upside down.
Then I thought I'd turn to the locking bar. This is very much option 1 so I'm expecting to have a load of different arrangements before I settle on the best way of working. This version using the push rods on the frame which pass through a 'key hole' shaped hole. A piece of brass tube will only go through the large part of the 'key hole'. I used a piece of square brass tube as the basis of the locking bar as it is stronger than a sheet material. I drilled 2 1.2mm holes 5mm apart for each lever and then opened both the holes out to 4mm on one side and one of them to 4mm on the other. The I joined the holes up with a piecing saw and a dremel to make the shape required.
The photos below show the operating sequence.
Initially all the levers are locked as the piece of tube around the push rod is trapped behind the lock in the small part of the 'key hole' shape.
The lock moves the the left aligning the large part of the 'key hole' with the push rod.
A lever (in this case lever 2nd from the left is reversed, pushing the piece of tube through the larger part of the 'key hole'.
Finally the locking bar slides back to the right locking the push rods again, in this case with the piece of tube on lever 2 on the other side of the lock.
It works in theory, I just need to try and connect a servo to the locking bar now!
I think I'd like to make the locking 'spring loaded' so the servo pushes the locking off, but a spring pushes it back. That way if you release the catch handle, but the lock isn't quite aligned exactly the servo can just go back to the locked position but a spring actually does the work.
Any one got any better ideas?