Tuesday, 13 June 2017
I forged a small spring to hold the tumbler down after it has been shot to stop it bouncing back. It took a couple of tries and snapped once, all good fun though.
There are 3 springs in total, one to operate the safety catch peg which also acts as a trigger return spring, one small leaf spring (from a bit of clock spring) to operate the little detent pin which gives a nice click to the safety catch and the forged spring to stop the tumbler bouncing back. I've kept the mechanism compact by having the 3 springs sort of overlapping each other. The safety catch is in the centre with the ident spring one side of it and the non return spring running along the other side.
It was built with very little actual measurement, basically it all starts with the nut and trigger made of plywood first.
I'll let the pics speak for themselves.
The pic of the spring shows the one that broke, however I softened it and re-shaped it. This time I heated it red hot and let it cool slowly, it was springy enough, but could be bent, so I didn't bother hardening and tempering a slightly soft spring is going to be more reliable than one which might snap. It was made from a length of silver steel.