Precision Grinding a Hardened Shaft with an Improvised Toolpost Grinder

[tonyfoale]

Sounds intriguing, Tony - any follow-up posts with pics, per chance?
Any data on the ball screw cross slide enhancement would be much appreciated, at least by me...
ATB
Johan

Johan,

I do plan to make posts on both of those subjects and also another recent job, I converted the screw on chuck mounting to a Bayonet type. This provides for a quicker chuck change, a more accurate chuck change and the ability to run backwards. Here are some teaser pix.

[olderdan]

Nice work Tony, I am particularly interested in your bayonet chuck mounting conversion. I have long thought of a way to convert my screw on chucks while keeping the original mandrel (plain bearings) judging by the marks on your mandrel it would appear to be the original. I am thinking modern adhesives may provide the answer but any ideas would be well received.

[tonyfoale]

Nice work Tony, I am particularly interested in your bayonet chuck mounting conversion. I have long thought of a way to convert my screw on chucks while keeping the original mandrel (plain bearings) judging by the marks on your mandrel it would appear to be the original. I am thinking modern adhesives may provide the answer but any ideas would be well received.

Alan,

I'll make a post on that topic separately. When I got my lathe it came with a spare spindle with a bit more meat at the chuck end. So I was able to still use the lathe for preparation of the other.
BTW Did you get my email from a day or two ago?

[olderdan]

I didnt because my email address has changed,I will PM you with my current one.
Regards
Alan

[Saltfever]

Nice Tony! I’m kind of confused by the term “bayonet”. It kind of looks like the beginning of a Long style or “D” type taper mount. Or were you referring to sumptin else?

Your ball-screw conversion, as well as your very unique thinking for the mount, deserves its own post. Very much looking forward this work.

[tonyfoale]

Nice Tony! I’m kind of confused by the term “bayonet”. It kind of looks like the beginning of a Long style or “D” type taper mount. Or were you referring to sumptin else?

Your ball-screw conversion, as well as your very unique thinking for the mount, deserves its own post. Very much looking forward this work.

As I said in my original post here. I shall be doing dedicated posts on on each of the three things mentioned, but to answer your question briefly. My preference is for the long nose taper style but that would have required making a lot of swarf from big lumps of steel or CI for the chuck backplates, whereas the D style or bayonet only needed a minimum of work modifying the existing backplates. "Bayonet" is not my term it is a recognised standard. The taper dimensions etc. are mostly the same as a D type. There will be full details in the dedicated post. Meanwhile

[Saltfever]

Opps! . . . I was thinking of the Nikon, Pentax, etc., bayonet lens mounts requiring a twisting motion. Totally forgot the term applied to the lathe tapered mounts I used years ago. Age and cross-culture technology. . . sometimes an unfortunate mix! LOL

I’m very interested in converting my screw thread Sheldon lathe so will be watching with interest. Many thanks for the dimensions.

[tonyfoale]

Opps! . . . I was thinking of the Nikon, Pentax, etc., bayonet lens mounts requiring a twisting motion.

It does require a twisting motion, not the chuck but a holding ring (the bayonet??)