I have two Wolf Jahn 8mm WW pattern lathes. One is a (probably) newer standard type with a 12" bed and a single foot. I just purchased the other one. It has a 16" bed with two feet and, judging from the condition, it is quite a bit older.

To my surprise, the head and tailstocks for these lathes are not interchangable.

On the 12" bed, the distance from the top surface of the T-slot to the flat top surface of the ways (not the beveled surfaces) is about 0.019". On the long bed, the measurement is about 0.0205".

The difference is enough so that the locking lugs on the short bed fixtures won't quite engage the T-slot on the long bed. Conversely, the long bed fixtures won't lock tightly onto the short bed.

I have been under the impression that components for WW pattern lathes, especially those from a first quality manufacturer, would be interchangable. Apparently, this is not the case.

Can somebody explain what is going on? Do these precision machine tools vary that much from one run to the next? Are there different grades or vintages of these WW lathes with different mounting surface dimensions? When buying attachments in the future, is there a way to know which items fit what beds?

Any information would be appreciated.

Maybe one is designed for production work? Here's a link to some information. Wolf Jahn 50 mm WW Lathe

RR