Truing Round Work in the Taig 1030 4 Jaw Independent Chuck

The Taig 1030 4 Jaw independent chuck is a versatile and strong accessory. I generally prefer to use it for round work over the 1050 3 jaw chuck as it grips strongly, and the work can be trued to almost no runout in a few minutes. Truing work in the 4 jaw chuck can be daunting to the novice however, as it requires the use of a dial indicator to true the work. Here are some pictures and notes about the process of chucking round work in the 4 jaw chuck.I may add more details on truing other work if people want.

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4 jaw chuck

The 4 jaw chuck. We want to true work by pairs of jaws. Get the work centered as close as possible by eye. Use the rings scribed on the face of the chuck as a guide.

If we loosen jaw #3 and tighten jaw #1, The work (the red circle) will move to the right. If we loosen jaw #1 and tighten jaw #3, then the work will move to the left.

Always loosen one jaw before tightening the other jaw.

dial test indicator 4 jaw

A dial indicator. When the tip of the plunger is rested on the work in line with one of the jaws, the dial set to zero, then you can rotate the chuck 180 degrees and see which way the pointer moves, and how much. You want to adjust each jaw half of the pointer movement, in stages. Take it slow and check the indicator often, as it is your friend!

Tightening the screw on the jaw bearing on the side of the work the indicator plunger is bearing on will cause the pointer to move CCW, after loosening the opposite jaw.

Loosening the screw on the jaw bearing on the side of the work the indicator plunger is bearing on, and tightening the screw on the other side, will move the pointer CW

Always view the dial square on, so you don't make an error.

open 4 jaw chuck The chuck opened up to accept the work
bar chucked A 1" bar chucked and roughly aligned by eye.
indicator 4 jaw How I use an indicator on the lathe. It is a bit more cumbersome to measure from the top, as the opposite screw is harder to access but I prefer to look at the top of the taig due to it's height. I made the indicator holder and it is always mounted and ready to use.
indicator magnetic base Using a typical large magnetic base.
small test indicator base A small test indicator magnetic base. You can also use the toolpost to hold an indicator. A test indicator will usually give a more accurate result but allows less leeway in setting up as the range is smaller (as is the dial) You can get it close with a .001 indicator then switch to a .0005 or even a .0001 if you are feeling somewhat crazy.
truing work in 4 jaw chuck Indicator at Jaw #1, the dial has been turned so the pointer is at zero. Indicators are relative, rather than absolute measuring instruments, so don't be afraid to rotate the dial.
truing other jaw in 4 jaw chuck

The opposite jaw reading (remember it was set to zero on jaw 1) showing the runout is about .045"

Sorry about the poor quality of the pictures, I got too much shine from the dial indicator crystal.

again chuck truing... Rotated back to #1, I loosen the jaw a tiny bit
another chuck truing shot rotated back to #3 and the jaw is screwed in, moving the work away from that side, and causing the pointer to move CCW (about .038")
and yet another 4 jaw chuck truing picture #1 is now at about .011, so we have runout now of .038-.011 or about .027 runout. Getting better. Loosening the screw on #1 again a bit
another one, gosh! Tightening the screw on #3 now moves the pointer to about .022"
this is boring And #1 is now reading about .024" I have overcompensated a tiny bit, but the runout is now about .002"
really, really boring One more adjustment (loosening #3 and tightening #1) and I get the #1 jaw to read .023"
when will this end? Which means the #3 jaw also reads .023" Don't be afraid to rezero the dial if you start forgetting where each jaw is - it can be convenient to always make jaw #1 zero.
not now... rezeroing the #1 jaw
last 4 jaw chuck truing picture...

and rotating around #3 is also at zero.The work is now true between #1 and #3. You now repeat the process for jaws #2 and #4, then recheck #1 and #3 in case you threw everything off a bit.

Remember that round stock is rarely round, and sometimes not that straight, so try and true it at an average point.

Believe it or not, it only took me the few iterations above to true the work. Sometimes it takes longer, especially when trying to get to .0005 or less runout. You can use the same technique to indicate a bore true, using a test indicator or hole attachment.

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