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:
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:
Unfortunately the arbor drawing is still "under contruction" (and has been for a couple of years, sorry).
Further looking found these on ebay:
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.
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.
one is a 1/2 arbor which also has the large driving disk.
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).
No it was off ebay a month or so ago, just finally got a chance to pick it up. Thanks for the ideas, I saw the ones on ebay, I just never seem to win. They pay as much for the arbor as the machine cost itself.....Thanks everybody.
If you watch your local auctions, you might be able to pick up a machine with tooling or a tooling lot at a reasonable price. The Bayport auction was unusual in that they had 12 #12's at the auction. Most of them went for scrap, unfortunately.
I recently made an arbor for a small Clausing horizontal. I used a 1" endmill holder as the root, and turned a bar to fit it, then placed the two between centers and turned the arbor to size. Worked very well until I stuck a pair of 6" cutters on the arbor, and spun the arbor in the endmill holder. Id only secured it with a single screw. Remaking a new one, now secured with a bit of loctite and both screws..it chews metal quite happily with both cutters.
BTW..doing it this way, was the fastest and most accurate way Ive found so far in making arbors.
The methodology of the left has always been:
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