How do you center your rotary table on your the xy axis?

For my router I am happy with low precision (0.5mm) so I use optical alignment. It is easy to measure the offset between the tool and the cross - once this figure has been entered into Mach, alignment is a straightforward procedure.  http://www.cooperman.talktalk.net/files/17.htm

Tweakie.

I dont have a rotary table but often set up a chuck on the table or shove the manual indexer on. Way I centre, or for that matter find the centre of a circle on anything clamped to the table , is I use an edge finder and move on one axis and touch off, I then zero that axis DRO then move and touch off the opposite side and then clcik on the DRO and type /2 and press the enter key, you have now just found the centre distance on that axis. Repeat for the other axis and you have now found the centre of the circle. It is exactly the same procedure if you want to find the centre of a rectangular part.

Hood

Hood,

There is a wizard that does just that. You touch off 3 points on a circumference of a circle (or 4 if you like) and it automatically calculates the centre. You probably knew it, but just in case

And while on the topic I will add another method I use to centre a chuck on the mill's table. Hold a round bar in the mill, lower the head and chuck the other end of the bar in the chuck. Now it's perfectly centred, zero the DRO's and use clamp the chuck to the table. Fast and easy.

Dan

Dan, yes I knew that but too much hassle going in to a wizard for me, much quicker to just jog via the MPG and zero out the DROs as I have full control over Continuous and step jog via rotary switch on the panel. I can have it done before the wizard has opened, but everyone to their own

Hood