Centering a Chuck to a Rotary Table..

[MWParticipant @mw27036]

Yeah, so the title is fairly self-descriptive but i need help centering a chuck to a rotary table thats Tee slotted. Its a standard 4 inch, 3 jaw lathe chuck, i never had a "big" rotary table before this one and my previous was directly threaded to the miniature table to avoid concentricity issues.

I need to do this because although its not too bad for cutting horizontal slots, when i need to produce a hole pattern everything is slightly off position, because the lathe chuck hasn't been precisely centered.

I've thought of a solution because the rotary table has a 2 MT center bore, i'm taking this as a heavy hint that i can use this to turn an appropriately sized ally plug to align the center bore of the rotary table with the lathe chuck center bore.

Am i on the right track, does anyone know of an easier way that i might've missed?

Michael W

[MWParticipant @mw27036]

[Ian ParkinParticipant @ianparkin39383]

I use a mt 2 test bar in the hole

grip the test bar with the chuck and bolt the chuck down

release grip and remove the test bar

[MWParticipant @mw27036]

I didnt think of that but it sounds like a plan, batman! I'd only do a duff job of turning a dowel to fit a MT. They're pretty cheap these days so i'll purchase one, thanks.

Michael W

[Chris Evans 6Participant @chrisevans6]

I have a 5" chuck mounted on a 5/8" thick rectangular back plate with two elongated slots in the back plate. I just nip it up on the RT and chuck a diameter similar in size to the component or the actual component then spin the table to set concentricity. Bolt down tight when set.

[Howard LewisParticipant @howardlewis46836]

If you want to be precise clamp down the table, and site a mag base beside it, with a DTI on it.

Clock a piece of round bar, held in the chuck and keep adjusting the position of the chuck to get minimimum run out.

If you can mount the chuck on an arbor (2 or 3MT Arbors are available with Myford thread/register, maybe Boxford also?), this will make centering on the RT an absolute doddle.

You could even make up your own, if you think that you will need to do this in the future.

Once centered on the RT, then you use the DTI and round bar to centre the R T under the Mill or Drill spindle.

HTH

Howard

[Author]

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