Long crank pins

[Dave Harris sctchbld]

I see now. I wonder if they make small dies to turn threads on the outside of a rod... What size screw are you using? 2-56? I basically drilled a hole in the counterweight, inserted the appropriate size brass tube, and then tapped the inside of the tube for a 00-90 screw. That may not work for you if you are using a larger screw, because the wall thickness of the brass tubing may not be thick enough to allow for the threads on a larger screw.

Edit - I just looked, and K&S makes a 2-56 die. You could use a brass rod, drill out the driver, and press/epoxy the rod in. Then thread the outside of the rod, and attatch the mainshaft with a 2-56 nut.

Yes , small dies & taps are made . The die is properly called a watchmakers draw plate. it has both tapered holes to pull a wire thru to size it in steps to what is needed, it also has the slotted hole which will then thread the wire . To give an idea of how small a piece can be threaded the hole marked 8 will just pass an.020 wire --7 won't!

The taps are also the same sizes. They are both Metric, but if you are making your own studs & nuts it makes no difference.
I found these on E Bay in jewelers supplies , between them I think they were about 20 -25 bucks , a bargain as far as I am concerned .
I once asked a Swiss trained watchemaker ( they are by & large a snooty bunch) how to how to get something like this & he informed me almost nobody made them any more & it would cost BIG bucks --hundreds!!
I guess , considering that in order to graduate watch school they have to SCRATCHBUILD an entire watch, ALL of it , gears, springs, case , screws, every thing & each piece is examined by the teacher as it is finished-- any flaw == even a scratch & it is instantly smashed with a hammer -- make another!, they have a right to be snooty.!