Tony Duell wrote:
My Myford
Super 7 Lathe (about 7 years old) has a seemingly random mix of
Whitworth (BSW), BA, and metric screws. Mind you, you do get a toolkit
(spanners, allen keys, oil gun, C-spanner for the headstock bearings,
etc) with it, so it's not so bad....
Sometimes you just have to wonder "What were they *thinking*?"
There is, I believe, a reason for it. Originally (the design is something
like 50 years old), it was all Whitworth for the large size bolts and BA
for the small stuff. That was, of course, typical for British engineering
at that them.
More recently they found that Whitworth allen-head screws were _much_
more expensive than the equivalent metric ones. So they went over to
metric for things like the bolts holding the headstock to the bed, but
kept Whitworth for the bolts used in the T-slots of the cross-slide, for
the spindle thread, etc. THat was so all accessories fitted all machines.
After all, if you buy a lathe, you expect to be able to get bits to fit
it in 10 or 20 years time (the computer industry could learn a lot from
this....)
-tony