Rotary table ? What is the right tool for making bayonet lens mounts ?

I am not sure what your exact setup would be but I would try to use a compound topslide with the taig lathe.

------------------------------------------------------------ Bo-Ming Tong Jan 11, 4:56 pm

I wish to buy a manual lathe to turn predominantly cylindrical parts. I will be trying to machine some bayonet mounts for a photographic lens. Also, I would be drilling a cylindrical screw hole pattern. It appears that I need both a lathe to turn the basic shape and a mill with a rotary table to mill the bayonet and drill the hole pattern.

However, I do not wish to put hundreds of pounds of gear at home. I would like something really small like the Taig micro lathe, and use only one machine to do the whole job. I can put milling cutters on the spindle and the workpiece on a milling attachment, but that only lets me mill in x-y directions. However, making a bayonet mount requires circular cuts.

If there is such a thing as a rotary table for a lathe, or you have some other ideas, please let me know. Thanks in advance !

What it looks to me like you might want to look at is a cutting spindle that you can mount on the cross slide of the lathe to allow the arcs to be cut. Could be as simple as clamping a Dremel Tool to the cross slide or building a miniature milling head along these lines

though you don't have to get that complicated, unless you want to.

Cheers Trevor Jones

Trevor,

Thanks for your informative reply.

I think this is like using the spindle as a rotary table, but I am not certain if I could dial in angles accurately that way.

It also looks a little bit like a "3-in-1" machine... Well, I never really understood how a "3-in-1" works having never seen one in action or even pictures thereof, but my guess is...

- in lathe mode, the headstock holds the workpiece and the tool rest holds the tooling

- in milling mode, the tool rest holds the workpiece and the mill holds the tooling.

Is that right ?

Yes it is using the spindle as the functional equivalent to a rotary table. It has it's limits, but can be useful.

To dial angles accurately, one attaches some form of angular reference to the spindle. This can be as complicated as a full featured dividing mechanism, with (usually) a worm gear and a dividing plate, or as simble as a protractor and a pointer of bent wire. This is nothing like a 3 in 1.

To see a 3 in one machine the Harbour Freight website has about the best pictures that I can find on short notice.

Outside of some careful planning, it is difficult to use a 3 in 1 to mill an item held in the spindle.

If you get one of those, you still have to deal with how you will deal with rotary motion, which will pretty much mean a rotary table or using the spindle as previously described.

Cheers Trevor Jones

I found this item when I googled Taig and rotary table.

it helps... I might get one of these for my Taig lathe.

---------------------------------------------------------- Bo-Ming Tong Jan 11, 4:56 pm

If there is such a thing as a rotary table for a lathe, or you have some other ideas, please let me know. Thanks in advance !

Thank you. You helped me eliminate all 3-in-1 machines in my consideration because I cannot easily mill something mounted on its spindle.

As a beginner, I have no confidence at all at angular accuracy, which is good for me in the sense that by method of elimination I would have to get a rotary table which is accurate out of the box. However, all rotary tables take up enough space to kill my "micro" plans, moving me up to the "mini" class, a fact that I am still trying to accept. The reality is that although the parts I am trying to make are small, the accessories I need to make them accurately aren't. Particularly, I am looking at Mike suggestion of just mounting a mill rotary table on a lathe. I am trying to work out how to align the rotary table, especially in a vertical position, to the spindle. (I need both vertical and horizonta because I need milling both from the side and on the face.) The center of the rotary table can be no more than 1 inch higher than the center of the spindle because my milling cuts are all more than 1 inch away from center. (As a lens mount, the center is always bored out.) And I still to keep the cross slide so that I have control over the radius. Does this sound like I will have enough room for let's say a Chinese 7x10 ?

Once again, I wish to thank all of you for helping me on this.

According to Bo-Ming Tong :

Hmm ... maybe not. Take a look at the following web page:

That is the web page describing their 4" rotary table, and it looks like an excellent guide to what you will need to consider when using one. I would suggest printing it out for later perusal, whether you get the Sherline table or something else.

Note that the Sherline table can be obtained with a hand-held electronic controller, to allow partial CNC operation.

IIRC, from the early part of this thread, you were talking about making things like bayonet mounts for camera lenses, and I think that this would be within the capabilities of this table, along with a Sherline chuck (for workpiece holding), and even a Sherline tabletop milling machine.

You can back up from that URL to their main entry point:

and read about their lathes and mills. A lathe would be nice for making the round part of such bayonet mounts, and the mill with rotary table for generating the bayonets. (I'm assuming that the size range will be similar to the old Nikon F lens mount. I'm not sure that you would do as well with something the size of the Hasselblad lens mount.)

Other projects may still force you into a larger series of machines, but lens mount bayonets for 35mm sized cameras should be well within the range of the Sherline.

You could also use the Sherline rotary table on a Taig tabletop milling machine.

Good Luck, DoN.