Hi all
One thing that really impressed me when I began the overhaul of my #13 was the care and craftmanship put in each part.
You gotta be pretty dedicated to your work to be willing to make such a cog, just because you think a key isn't the *very best* way to drive a shaft...
It is probably true, from a purely mechanical point of view, that a key isn't the best system, but it did and does the trick for 99,999% of machine tool builders ! Take a look a that spindle : wow
!
And as you guessed, the fit is *perfect*. On the other hand, such a work of art also has its downsides : try to go to your local industrial supplies store and ask for such a cog !
"Somthing's strange with the bore... Dunno why, but I can't seem fo find the same diameter twice...
"
For Bernard, here's the boring head I told you about (here shown with a SGIP removable schrank).
The pics don't do justice to that device, wich has more to do with a surgical tool than with a machinist one.
I recognized this boring head on a #13 sale brochure, and it was sold as an accessory by Schaublin. I'll let you do the conversion to imperial but even in metric, 0,005mm is pretty tight a tolerance !