Dave, a fine pair of pistols. I am sure that between you and Roller you can get those tumblers cut correctly.
Now, can either of you tell me, or show me, how the little shelf is cut for the fly? And some flys ride on a pin in the tumbler, some have a pin on the fly that sticks in a hole in the tumbler. Between the two, can you tell me why the difference? I can see a vertical pin installed in the tumbler - is the fly with it's own post usually cast or milled?
And a Merry Christmas to all!
On my locks the fly and pin were made from a piece of 7/32" 0-1 oil hardening steel.I used a hollow mill I made with a reamed hole of .086 diameter and the inverted "V" it set in was .075 deep.The fly that hangs from the small bearing of the tumbler will have to be stopped with
two tiny pins exactly placed to stop the fly as it cams the sear over the half cock and the rear one must allow the sear to engage full cock.
I milled the inverted "V" on a heavy drill press,old American Delta running at maximum RPM and used a 5/64 or 3/32 stub lenght end mill with 3 flutes at a depth of .075.The "wing" of the fly was .070-.072 so it had room to work with no interference from the bridle.I have never made one with the fly between the tumbler and the lock plate.The fly and pin are integral.
The reason for the difference goes to the personal ideas about lock making.I think I made one with the fly hanging off the small bearing of the tumbler and pins for stops but it was a very long time ago.The 7/32 0-1 was milled to a thickness of ,070=.072 with a narrow strip of about .080 to acommodate the little hollow mill which is a shop made tool. Lock making as opposed to assembly of prefabricated is another skill set altogether.Selecting what material to use and the finding it in affordable quantities is step one and then comes at least SOME machine shop skills plus a bit of blacksmithing (springs) and in the absence of a milling machine,saws and files must be used instead.
I combined both.I also make my own screws from 12L14.The lock screws were copies of those found in high end English locks of the mid 19th century and I used 5/32 diameter which is the size of the screw heads and the threads are 4x40 or 4x48 or .107-.110 diameters.
I found both sizes in a fine Brazier lock made in 1865 so it's not a critical thing.Drill rod of 5/32 is also used and I used it for years.
Bob Roller