I spent a little time in the shop today and got the mounting screws made for the sight and most of the frame re-made with the latest design changes.
The screws were #5-40 oval head machine screws. Nothing to difficult, but I'll post pictures just the same.
The screws were made of O1 and the first step was to turn the major diameter for the #5 screw and form the 100º angle on the head. There are many ways to form the angle but I chose to generate it by setting the compound to 50º and machining it with the point of the turning tool.
Short, small diameter threads like this are a pain to single point so I decided to cheat and use a die. Besides, how often do you get to use a #5-40 die? The body of a drill chuck in the tailstock was pushed against the die stock to ensure a square start.
Once the thread was cut, the screws were parted off a little long.
They were then held in a collet and the crown machined with a form tool.
After "crowning" they were held in a collet block and a .032" x .050" slot cut for the screwdriver.
Next, the base needs a little more modification, the frame needs to be finished and the leaf spring made for the detent. That will pretty much wrap up the sight project.
Tom