585,973 active members*
4,065 visitors online*
Register for free
Login
Results 1 to 12 of 12
  1. #1
    Join Date
    Nov 2009
    Posts
    81

    centering a vise

    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.

  2. #2
    Join Date
    Nov 2004
    Posts
    260

    Smile

    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

  3. #3
    Join Date
    Oct 2009
    Posts
    118
    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.

  4. #4
    Join Date
    May 2010
    Posts
    27
    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.

  5. #5
    Join Date
    Aug 2009
    Posts
    684
    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

  6. #6
    Join Date
    Feb 2010
    Posts
    371
    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!

  7. #7
    Join Date
    May 2005
    Posts
    2502
    Quote Originally Posted by AiR_GuNNeR View Post
    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
    Try G-Wizard Machinist's Calculator for free:
    http://www.cnccookbook.com/CCGWizard.html

  8. #8
    Join Date
    Nov 2009
    Posts
    81
    When you guys use a machinist square, does your vice become centered, or do you still need to check with a dial indicator?

  9. #9
    Join Date
    Apr 2010
    Posts
    486
    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

  10. #10
    Join Date
    May 2005
    Posts
    2502
    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.
    Try G-Wizard Machinist's Calculator for free:
    http://www.cnccookbook.com/CCGWizard.html

  11. #11
    Join Date
    Jul 2009
    Posts
    37
    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.

  12. #12
    Join Date
    Mar 2003
    Posts
    4826
    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.
    First you get good, then you get fast. Then grouchiness sets in.

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)

Similar Threads

  1. A BETTER TAP WRENCH! SELF CENTERING!
    By northernmach in forum News Announcements
    Replies: 20
    Last Post: 08-20-2015, 01:55 PM
  2. Centering my Tailstock
    By JWB_Machining in forum MetalWork Discussion
    Replies: 1
    Last Post: 05-14-2009, 07:56 AM
  3. Centering problem
    By daanmuller in forum MetalWork Discussion
    Replies: 6
    Last Post: 04-04-2009, 11:41 PM
  4. how centering new axis
    By Masi in forum Fadal
    Replies: 2
    Last Post: 05-28-2008, 08:53 PM
  5. Home Made Vise Stop - For 6" Kurt Vise
    By widgitmaster in forum Bridgeport / Hardinge Mills
    Replies: 20
    Last Post: 12-15-2006, 03:49 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •