Appears to be a Horizontal Mill Arbor... but for what machine?

[Scott(GA)]

I recently purchased a Delta-Rockwell 11-inch Metal Lathe via Craigslist. Inside the cabinet - along with other items - was this box.



The object inside is 16-1/2 inches from end to end.





The diameter of the shaft with the spacers removed is 1". The spacer's outside diameter is 1-9/16" .






The thread inside this taper is 1/2"-13. I measure the wide part of the taper at 1.23". Most anything I've seen on the interweb that looks something like this is usually 1.25 as a spec.






The only marks I've found on this item - or the box - is this "21" stamped inside the flange.

I've been told it appears to be an arbor for a Horizontal Mill and that is certainly what it favors. However, I haven't seen an example on the internet that has a taper on both ends.

Regarding the seller being asked for details... I am confident he would have no idea based on my interaction with him during the purchase.

Anybody have any thoughts?

Thanks,

Scott

 

[Bob Korves]

It looks it has a 30 taper spindle taper at the drive end. It will fit most any horizontal mill with that taper which can use that length of arbor. The other end looks like a Brown & Sharpe #9 taper, or perhaps a #3 or #4 Morse taper. Never saw one like that before. Usually, there is the drive taper at one end and then a hardened straight shaft at the other end that goes in a bushing in the arbor support.

 

[4GSR]

Must of had some kind of tapered bushing in the overarm support instead of a straight hole. At least with a tapered bushing you can compensate for wear. On the other hand, that could have been for a roller bearing overarm support that you used to find on the much larger horizontal mills. As bob said, most likely a No. 30 taper, CAT style. Person may need a slightly longer draw bar to use with this one.

 

[Scott(GA)]

A few more pictures that may be useful...





Note the lack of a key on the arbor.






No keyway in the spacers and it is a more complicated part than I expected when I first examined it. Note the Inside Diameter is not constant but is actually a larger value inside the spacer a bit.










Just some pictures of the tapered ends with the threads.


Scott

 

[benmychree]

The larger diameter inside the spacers makes it cheaper to internal grind the hole; I have seen arbor spacers before with no keyway; is there a keyway in the arbor? If not, this arbor was intended for very light work, driving the cutters by friction alone, which does work fine for such as slitting saws.

 

[Silverbullet]

I'd guess it's a 30 taper, any name on it anywhere? Why not sell or trade for something you need it may bring $100. Or more

 

[Scott(GA)]

I'd guess it's a 30 taper, any name on it anywhere? Why not sell or trade for something you need it may bring $100. Or more

Silverbullet,

I probably will attempt to sell it at some point. I thought it would be easier to attract a willing buyer if I could identify it. Ha!

Best regards,

Scott

 

[Bob Korves]

I probably will attempt to sell it at some point. I thought it would be easier to attract a willing buyer if I could identify it. Ha!

I am reading "Gears and Gear Cutters" by Ivan Law. The book is downloadable on this site at:
http://hobby-machinist.com/resources/17-gears-and-gear-cutting-pdf.173/
Just so happens that on the last page of chapter 9 there is a gear cutting setup with an arbor like the one we are discussing. It is on the last page of chapter 9, page 84 in my hard copy version. The book was written by a hobbyist in England for hobbyists, and #2 Morse taper is mentioned in relation to gear cutting arbors on the horizontal mill. So perhaps some British or hobbyist mills use that arrangement. By the way, he states the Morse taper #2 is typical for all arbors in the drawing on that page. I suppose from the photo you posted that yours might be MT3. So, maybe it is not so rare after all. The book is copyrighted 1988, so the arbor might not be an antique, but rather something in relatively common use. FYI, and send me my share of the sale price...