Arbors for Clausing 8540 Horizontal Mill

I'm in the same boat but have one fairly decent original arbor. Near as I can tell, the standard NMTB 30 arbors that are sold by the tool supply places will fit the spindle but are too long to mate properly with the arbor support at the other end. Clausing must have used a custom arbor, no longer supplies them, and doesn't even have the dimensions, though another owner supplied them to me before I got my original arbor. If you find a stash of original arbors, please let me know

I do have a couple of import arbors and it should be possible to retrofit them but I haven't attempted it yet. They are probably hardened steel, and I assume that the arbor end would need to be ground to fit length and diameter.

BTW, I have most of an 8550 (8540 sans power feed) left and am perpetually intending to part it out on Ebay later this year. Let me know if you need something.

Mike

There are plenty of aftermarket arbors out there. Reliable Tool has bins of them.

The key..is the bearing stub on the outboard end. It must be the same or larger diameter as the bearing in your arbor support, or you must make a bushing. If its larger..you simply turn it down on a lathe.

I too have an 8540, was using it extensively yesterday. Ive 3 arbors..a factory 7/8ths, a factory 1" and a home made 1 1/4"

They are quite easy to make. Get a standard 3 taper end mill holder,..say 1", which is about the best size for the Clausing..and a

1" piece of round bar stock (preferably ground) and fit them together. Machine a bearing stub on the outboard end, thread just beyond that for a nut to hold the spacers and cutters tightly..and if you want to get fancy..mill a keyway to fit the cutters and Voila! You have a new arbor for your miller.

Gunner

"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner

Gunner,

I'd thought that the aftermarket arbors were hardened - am I mistaken?

Mike

Aren't most arbors hardened?

That's an interesting idea - do you use anything to hold the shaft to the EM holder? LocTite? Weld?

Mike

Shrug..I dont know. Ive modified several of them (originals) over the years, shortening and rethreading to repair badly damaged threads in both cases, and they didnt appear to present much resistance as would hardened material. I would assume that a bit of heat with a rosebud on the end you were going to modifiy, would anneal them well enough, and the machining would repair any warping if any occured. Stick them into a tube of water or wrap them with a damp rag below the area to be heated would seem to be indicated ...

YMMV of course.

Gunner

"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner

On the 3-4 Ive manufactured, I simply ground a bit of a flat on the stub that went into the endmill holder, and then tightened up the setscrews pretty tight.

The hardest part is making the spacers, as they need to be completely parallel in both axis and the ends perpendicular to the bore. I made up a tool to grind the ends, by turning a stub the proper diameter, on the lathe, then parting it off, and then facing the fat end (think inverted mushroom) while holding the stub in a collet or indicated 4 jaw.

If I get a spacer that is damaged, I put the stub on th surface grinder, slide the spacer over the stub, knock off a grand, reverse it and knock off another grand. Now I know the ends are perpendicular to the bore, so there is no tendency to tweak the arbor when tightening it up.

While not perfect..its close enough for me, using the old machines I have to work with.

Gunner

"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner

I think the ends perpendicular to the bore is sufficient, isn't it? That's enough to ensure that the ends are parallel. Doesn't facing, boring, and cutting-off give you that? How out-of-perpendicular would they be?

Bob (I am especially interested in this as making an arbor for my Atlas baby mill is on my to-do list.)

Not much apparently - I just checked an original Clausing arbor and an aftermarket arbor and neither were hardened. At least not on the arbor support end.

Mike