Need Help!- centering a vise

[Micro Milling]

I want to make my vise perfectly center or straight on my table. I use a square, but when I check for straightness it is off a bit on my dial indicator.

When running a dial indicator over my vise, and only using the left to right axis, I have run out.

So then I try and have no run out by running the idicator over my vise and tapping it slightly. The problem with doing this is it takes forever to get it to have acceptable run out.

So I thought I would take a measurement on the left side of the vise, and then move the indicator to the right side and make it the same measurement on my dial indicator.
Well that didn't work because when I went back to the other side I had a diffierent measurement.

Seems like when I tap a corner of a vise to move it the whole vise moves.

I then spend another 15-20 minutes of tapping the vise and moving from left to right like 50 times trying to get acceptable runout on the indicator and I finally get it after a while.

Does anyone know an easy way to use a dial / test indicator on a vise to get it to be straight? Simply running the test indicator from left to right and lightly tapping the vise takes ages to get it straight.

[Torsten]

It actually goes pretty quickly, once you have done it a few hundred times before.
How dose your vice bolts to the table?
Usually next to the solid Jaw (backjaw) are 2 bolts to clamp it down.
First setup the vice visualy as close to square as posible.
Now use your indicator and move it against either the left or right side of the fixed Jaw, set it about .01 deep and lightly tighten the holddownbolt next to it. Make sure the other holddownbolt is loose.
Now move the Table towards the other end.
The Dial indicator is likely to go up or down, tap the vice in the apropriete direction so it will turn around the tightened bolt.
Notice the spacing between the bolt, the original dial start point and its current location.
If they are about equally spaced your original startpoint will also be moved by half the indicator reading, so you have to overshoot your adjustment by that much also.
Repeat this going back to the original start point untill you get it close enough to maybe .003", then move over the entire width of the Jaw, correct and lightly tighten the other bolt also.
Now go back to the start point and tighten the Bolt closest some more then back and tighten the other one some more.
Note that the vice can shift if you dont tighten the bolts carefully.
The Key to doing this is to be aware of the spacing between the Holddown Bolt and your current indicator location.
Good Luck

[leggazoid]

Tighten screw slightly on one side only. Zero indicator out on side with tightened screw. Move indicator to other side and tap vise until zero. Check again and repeat if necessary.

[Cknoble1]

Just a tip. When you are indicating your vice, select one side to work off of. Make sure you smack the vice away from the indicator opposed to smaking it towards the indicator. It will give you a better readout. If you want any advice on a simple way to indicate accurately let me know. either for a cnc or manual.

[christinandavid]

Agree with previous comments - clamp on one side to create a pivot point to make it easier to anticipate the movement from one end to the other. Eventually you will get the knack. Best results are achieved by clocking a parallel clamped in the vice.

One you have it perfect, drill and ream through the vice into the table. Then you can locate it in the future using a couple of extractable dowels.

DP

[AiR_GuNNeR]

I saw a post where a person took a plate and cut a chunk out of it so that it looked like an upside down U shape. The thickness matched the slot width on the table. He simply set the vise down, put the upside down U shape over the vice, between the jaws, fitting the two ends into the table slots. Then he tightened the jaws down and the five centered itself. Now just tighten the bolts!

[BobWarfield]

Originally Posted by AiR_GuNNeR I saw a post where a person took a plate and cut a chunk out of it so that it looked like an upside down U shape. The thickness matched the slot width on the table. He simply set the vise down, put the upside down U shape over the vice, between the jaws, fitting the two ends into the table slots. Then he tightened the jaws down and the five centered itself. Now just tighten the bolts!

Sorta like dat:



Been meaning to make one, but heck, once you've done it a few hundred times, it does go fast, LOL!

Cheers,

BW

[Micro Milling]

When you guys use a machinist square, does your vice become centered, or do you still need to check with a dial indicator?

[TarHeelTom]

I start with a machinist square, but that only squares to the piece of the table you're referencing. The final answer is always a dial indicator against the fixed jaw of the vise. Also interesting to run the dial indicator down the length of the vise, via the Y axis, of course.

Tom

[BobWarfield]

For getting close before the dial indicator, I use a 36" straightedge made by SPI. Chuck it up on end in the vise. Stand still and sight your table's T-slot edges against the straightedge.

You will be within a few thousandths and the dial indicator will take care of the rest.

Cheers,

BW

PS That one is from Machine Shop Trade Secrets.

[nicko17]

Set up the vice on the table with all the clamps to hold it down , but dont tighten them , keep it very loose.

Then using a text guage/dial indicator run it along the vice clamping area from one end to the other. Lets say there is a 50 thousands out , tap the vice very slightly on the one end if its lower or higher till it moves 25 thou. You always want to move half. Once you get it pretty close then tighten up you bolts slowly!! Check it again , loosin a little if its out again.

It gets easier each time you do it.

[HuFlungDung]

What is wrong with using the keys in the bottom of the vise? Granted, you may have to accurize them, but it is well worth the trouble, IMO.

Set up a 10 or 12 inch long straight bar, clamped directly to the machine table, and dial it in to perfection. Take your vise, invert it and clamp the jaws directly onto the trammed bar.

Now check the existing keyway slots for accuracy and touch them up if necessary, or cut new ones in a different place if that would be handier for your particular machine.

Make some close fitting keys that are tight in the vise keyways, and about .001" loose in the mill table slots. You might need to make step keys to accomplish this and you might also want to install them into the vise keyways and take some light truing cuts on the oversize keys with the vise upside down as described earlier.

I've done this for my Kurt vises and it works well. I simply place the vise in a convenient T-slot and clamp it down lightly. The .001" clearance means it could be out that much in 6 inches, so then I adjust it with a soft hammer, one way or the other. I'd be ready to go in a minute or so.