"tony" wrote in message
...
the good news: i'm a proud owner of a new-to-me bridgeport mill
the bad news: i live in italy and its almost impossible to find R8
anything
here

i've had the mill about 3 weeks now and have been running
around buying tooling. found a retired machinist who gave me
a great deal on drills/reamers/vices/blocks and... endmills.
he gave me 3 or 4 old (but never used) face milling cutters and
some dovetail milling cutters. also got some slotting saws.

problems is: no milling arbors.

the dovetails and slotting saws have a keyed hole.
the face mills, however, have a radial key (ie, the key
looks like it goes straight through the shaft, across
the top of the cutter. like "+" sign.

i'm wondering, should i try to make my own milling arbors?
and how? i dont have (or have access to) a cylindrical grinder.
i've got a lathe. (and a mill!)

i'm currently using collets in the mill. the work great as they
can accomodate metric tooling and my suitcase full of inch-sized
mills.

if i make a straight (cylinderical) arbor, will a collet hold it?
what kind of material should one use?

mail ordering anything from the USA takes AGES to get here.
and, if it doesnt fit the cutters right, sending it back costs more
than buying it.

suggestions on using the facing mills?
suggestions on making keyed shafts for the dovetail/slot cutters?

thanks,
-tony

ps.. can i change the R8 spindle for some kinda of MT spindle?
MT tooling is abundant here.

pps.. i have an adapter R8 - MT3 , but i can't use the draw
bolt through the adapter.

Tony,
You didn't make mention of the size of your miscellaneous milling cutters,
so it's difficult to provide a reasonable answer. Bridgeport mills are
not known for their rigidity (I own one) and don't lend themselves well to
large cutters. Assuming you have a collection of side milling cutters,
without a horizontal milling attachment, you'll be limited, for the head
won't tolerate unreasonable loading, especially when the arbor isn't
supported on each end. Overall, unless the cutters are on the small
side, you'll likely not be too happy with the results, and you could be
courting a crash.

If the cutters you refer to as face milling cutters are what are known as
shell mills, you'll have somewhat better luck with them, due in part to the
fact that they are run on stub arbors. Do be careful to not run them
excessively fast. HSS cutters in the larger sizes require relatively slow
speeds in order to avoid burning them. I'd suggest you check your
machinist's bible for proper speeds.

Side milling cutters are intended to be run under considerable load, which
requires, generally, more stability (rigidity) and horse power than you have
available, assuming you have a small Bridgeport.

If I was to make an arbor, I'd seek something like 4340, which you may be
able to buy already heat treated. If you can't find that material, look for
some already heat treated 4140, something in the Rc 30 range, so you can
still machine it. Full roughing, followed by careful finishing after
roughing, could provide an arbor that would run within acceptable limits.
It is important that you rough the item fully before taking any finishing
cuts. Otherwise you'll likely have an arbor that doesn't run true. If you
have the above mentioned shell mills, be certain to provide the drive keys
for them when making your arbor(s). Screw loading the cutters alone will
not drive them.

Changing the spindle could be more than you'd care to get involved in.
Personally, I'd just try to locate a few proper devices in order to use the
machine as it is. But then, I don't live in Italy! :-)

Good luck~

Harold