Gents - the spinners will be on the website but not for a while. Please direct your questions by e-mail or phone.
I'll do my best to help on this end.
The thread is 3.0 MM x .5 MM. Why? Who knows?
The probelm as I see it is that there are so many different 1/2 A shaft configurations - male or female thread, 4-40, 5-40, various metric, and so on.
Even our two .049s have different threads - male and female.
Our "big" engines make it simple - just about every crankshaft thread is 1/4-28 UNF male.
So, how about some suggestions - what would you like to see?
I'll take all feedback and maybe we can come up with a reasonable solution.
Bob Z.