"Harold & Susan Vordos" wrote in message ...
"KD" wrote in message
om...
I just picked up a van norman no 12, and it doesn't have any arbor to
use for over arm support, it has some small arbors and such, but that
is it. I know people have made some on there own, can someone explain
the process? Are you actually cutting the taper to slip into the
spindle or can you just make one in like 1/2 inch and use a collet and
the other end supported by the overarm? Appreciate any help.
The large taper of an arbor is intended to lend stability and provide the
driving force when using side cutters. When properly applied, horizontal
milling machines are capable of breath taking feed rated due to the large
number of teeth found on these potentially large diameter cutters. Based
on that, imagine the amount of torque necessary to drive the cutters without
slipping. Driving with a 1/2" collet would certainly not be in your best
interest. Even the largest collet you might have would be woefully lacking
if you ran a large cutter. I've seen up to 12" diameter cutters used on
#4 K&T mills. The mechanical advantage the cutter has is so great there's
almost no way you could drive it with a collet. Not taking a reasonable
feed is not the solution, either. Cutters that are not doing much work also
don't have much of a life span. Milling cutters that just scratch away at
material wear faster than one that is doing serious work, but cooled
properly with flood coolant.
Making or buying an arbor or two is really the best solution.
The Van Norman #12 has keys on the spindle nose that are intended to drive
the arbor. I don't have a photo of an arbor handy, but the keyways can
be seen (not very well) at:
http://www.metalworking.com/DropBox/...les/Worm09.jpg
The spindle in the photo has a 3/8 collet installed. The keyways are
at about 1 o'clock and 7 o'clock in the photo. The keys themselves
have been removed to prevent interference - they are of mild steel
keystock, and held in by socket head cap screws.
If you aren't feeling up to making a complete arbor, perhaps an alternate
design could have a straight shank to be held in a collet for centering,
and a disk to be driven by the keys?
I have an accurate drawing of a Van Norman collet on my webpage at:
http://home.att.net/~JEKasunich/vann...VN_Spindle.htm
Unfortunately the arbor drawing is still "under contruction" (and has
been for a couple of years, sorry).
Further looking found these on ebay:
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=2580871553
this is a 7/8 stub arbor without key slots. The smallish keyway shown can
engage a small key in the spindle, but I wouldn't trust it for high torque.
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=2580871974
this one is a long 7/8 arbor. Note the much larger disk - you can't see it
in the photo, but there are two notches in the disk to engage the keys in
the spindle nose for high torque driving.
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=2581712586
this one is a 1/2 arbor which also has the large driving disk.
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=2580873738
this is a flycutter (shop made as far as I can tell). The second photo
down on the left shows the key notches and small keyway very clearly.
Hopefully this info will be helpfull!
(BTW, I am _not_ the person running the auctions - they just came up
on a search).
John Kasunich