Brain Fade

[escowizard]

Ok, I know I am getting too old for this but..................

Please clarify for me.

1 Degree = 60 minutes

So on a rotary table, each degree line is divided up into minutes?
What about seconds?

For acuracy purposes, a table that is accurate to 40 seconds is pretty good, right?
Or am I just nuts?

I thought it went degrees, minutes, seconds.

[RICHARD ZASTROW]

Depends on the diameter of the rotary table. On a 60" dia. table 40 seconds = .0058". on a 6" dia. table 40 seconds = .00058".

It also matters what the measuring device is and how accurate it is.

What size is the rotary table? How accurate must it be? You can calculate backwards to find the accuracy you need. Then you'll know if 40 seconds is good.

Example: For a 60" table on a Horizontal Boring Mill the table was accurate in positioning to +/- 4 arc seconds. This was considered junk by a gentelman who made satelite tracking platforms.

Back to that old hack, "speed costs money, how fast do you want to go?".LOL

Dick Z

[escowizard]

ahhhhh
I think I do understand it in the direction I started from. lol

Its a 6" table.
My current table (being returned to vender) gave me .005" diff in 4° movements.
Completely unacceptable for my needs.
I think the prob is the gear cuts in the table itself.

There next better table claims 40 seconds accuracy and I thought that was pretty dam good.

So for a 6", that is pretty good to me. I need +/- .001 or better
I am grinding teeth that are 30° apart 12 total on a dia. of 3"

Money makes it better. Cant afford to finance the pentigon.

[RICHARD ZASTROW]

If it's just a matter of indexing to discrete positions, you might consider a "Super Spacer" or other indexer. They use replaceable indexing plates which can be made to precise spacing. Much less expensive than either a rotary table or dividing head.

If you have access to some machines, you could make your own.

Dick Z