Any clue what these might be from

In among some bits I picked up at a business closing auction, was a set of these small tapered arbors, but I'm lost as to what they might be from. I'm guessing that they might be specific to some sort of tool grinder (the business was a toolmaker), but haven't found any clues as yet.



The tapers are small, but don't match any tapers I know. At the big end they are around 14mm diameter, 10.5mm at the small end, and around 36mm long (in imperial around .55", .41" and 1.42" in length). This gives a taper angle of 2.8 degrees, or 5.6 included, which is much steeper than the self locking tapers such as Morse, but a lot less than the non-locking tapers such as ISO. From the thread at the base, I'm guessing that they have an active locking system. From the various dimensions, they look like they are metric (spanner flats are exactly 12 or 14mm).

There are a variety of different arbors, including the ones in the picture. The one on the right is a cute little collet (again looking like nothing I've seen before), others just hold the tool with a set screw (so guessing they are not ultra precise). They came with a number of diamond points (similar to the one mounted in the middle arbor), and other small grinding stones. One of the boxes had C.B.N written on it, which I'm guessing might be an indicator to Cubic Boron Nitride points or stones, another BTS?

I'd appreciate any ideas or clues!

Andrew

They are grinding wheel arbors from an internal grinding quill......like an Ex-Cell-O or similar......I have a tinfull of them with each internal spindle ,but they are obviously different size taper ,so I ve never tried to interchange them....or thought much about them...........Anyhooo,they probably also will fit some toolpost grinder or other,as well.

Tool post grinders, like the USA Dumore and Themac, use arbors like that. Also, Boyar Schultz slot grinding attachment for a surface grinder (pictures below) has arbors like that. Like, not exactly. I have a few orphan arbors like those that do not fit anything I own.

Larry

The collet chuck looks a lot like one of the ones that came as part of a set with the high-speed/internal quill for my Cincinnati tool & cutter grinder. However, as others note, kind of hard to say without taper specs opr engraved id.

smt

Moore jig grinder?, possible
Mark

You may want to go back and look at the machines listed for auction where you got these from, that should narrow the search?

Kevin

Thanks for all the comments. It looks like I was on the right track with some sort of tool grinder. It was a good idea to look back at the machinery included in the auction - I've been and done that, but nothing there looks likely. Of course it could have been disposed of earlier or via some other channel. No marking on anything, but definitely metric, so I'm guessing its probably a European machine - I assume any US or UK stuff would be imperial (though there is definitely metric based machinery coming out of the US now). Anyway, hopefully at some stage I'll figure out what these belong to - it's a pet peeve when very specific tooling gets separated from its machine!

Regards - Andrew

Good to mention the thread along with R or L, Indicator strike the taper at a one-inch distance, and micrometer the big end of the taper, and add taper length. that way someone may decide if they can use them.

Hi Larry i was wondering do you have a quill arbor for my Boyar Shultz slot grinder attachment for sale? Thanks