# Vise tramming



## Aukai (Jun 12, 2020)

How anal do you get for general purpose vise tramming? I seem to get down to the tenths, and then start chasing my tail. I'm using a DTI with a Noga holder in a R8 ETM ER40 collet. I'm at .0005 right now, I took my Kurt D688 off(78 lbs), and put the Glacern 4" on to see how I like it as an everyday vise.


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## benmychree (Jun 12, 2020)

As anal as you want, but how crazy is that?


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## Aukai (Jun 12, 2020)

That's what I'm wondering, do I want a padded room, or it'll do. My repertoire of precision machining is pretty slim, but I was practicing on this. Kinda answering my own question.


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## JimDawson (Jun 12, 2020)

I normally tram to +/- 0.0002 or better, normally takes me a couple of minutes.  Takes longer to set up the indicator than it does to tram in the vice. There is a trick to it.

I snug the the left screw a bit tighter than the right.  The set the indicator on the left side.  Then as I'm moving the table to the left, I'm bumping the vice with my hand in what ever direction it needs to go to reduce needle movement.  Then move back to the right, and set 0 on the indicator again.  Rinse/repeat as needed.  With a bit of practice you can do it in about 3 passes.  Then finish tightening the vice down. Check again if you like, but my vice never moves when I do the final tightening.


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## Aukai (Jun 12, 2020)

I do get needle movement when snugging down the right side hold down....


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## DavidR8 (Jun 12, 2020)

JimDawson said:


> I normally tram to +/- 0.0002 or better, normally takes me a couple of minutes. Takes longer to set up the indicator than it does to tram in the vice. There is a trick to it.
> 
> I snug the the left screw a bit tighter than the right. The set the indicator on the left side. Then as I'm moving the table to the left, I'm bumping the vice with my hand in what ever direction it needs to go to reduce needle movement. Then move back to the right, and set 0 on the indicator again. Rinse/repeat as needed. With a bit of practice you can do it in about 3 passes. Then finish tightening the vice down. Check again if you like, but my vice never moves when I do the final tightening.



That’s pretty much exactly what I do. 
It took me a bit longer the first couple of tries but now it’s about a 2-3 minute affair. 


Sent from my iPhone using Tapatalk


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## JimDawson (Jun 12, 2020)

Aukai said:


> I do get needle movement when snugging down the right side hold down....



Is that from backlash in the table or is the vice actually moving on the table?


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## Aukai (Jun 12, 2020)

I did not check that. I also have to go back and see how tight the gibs were, Normally I just have them snugged.


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## MrWhoopee (Jun 12, 2020)

If it's less than one of those little lines, it's close enough.


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## mikey (Jun 12, 2020)

I get it to zero. It doesn't take long to do and basically I do it similar to what Jim does. Just takes a little patience, practice and you'll get it. I use a Kurt 4" vise, a Compac 214GA 0.0005" DTI and I can dial it in a few minutes or less.


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## Aukai (Jun 12, 2020)

I'll get a little more practice....


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## ThinWoodsman (Jun 12, 2020)

Saw a two-indicator technique in one of the home machinist mags. One indicator on a magnetic base on the table, its tip on the top right of the fixed jaw. The other in the spindle. You start with both indicators in the same corner, and zero them using the X and Y handles. Then you traverse the fixed jaw using the X handle, and adjust the vise until both indicators read the same (usually nonzero unless your vise was already aligned) number. Finally, you monitor the dials while tightening the vise, and compensate when one of the needles moves.


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## Bob Korves (Jun 12, 2020)

The only thing I tram on the vise is the fixed jaws to be parallel with X and Z axes, and then cut soft jaws in place to make the vise match them, if necessary.  The more important part is getting the movements of the 3 axes of the mill perpendicular to each other.  We want a square and parallel part.  The vise just holds the part.  Of course, not much of the work I do needs anything near perfect geometry...  It is only worth achieving what is required to get what you need for the job at hand.


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## Lo-Fi (Jun 12, 2020)

I've taken to power feeding when tramming, saves any movement induced from turning the handle.

I don't tend to bother to zero the indicator - all I'm interested in is movement of the needle. Just let the table move, bump the vise until the needle stops moving. Possibly zero on the last pass if I'm wanting super accuracy. I'm down to about 30 seconds for a 0.0005" tram, which is good enough for me usually. Below that precision I don't find bumping really practical - too hard to modulate tiny bumps - and an arrangement with more finesse is better. A bar clamped to the table next to the vise with a screw/machinists jack pushing the corner works pretty well.


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## ErichKeane (Jun 12, 2020)

I always seem to screw it up when bumping, and had thought about using a special made device in the T slot to do so, but cannot believe I never thought of just clamping something with a thread to it!  That would make it so much easier!  Between that and the 2 indicator method, I suspect you could get this down to zero!


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## benmychree (Jun 12, 2020)

For most work, all I do is to have fixture keys fit my vise and the table slots, near enough is close enough!  Of course, the keys need to fit snugly, this works best on a swivel base vise, so final adjustments can be made only as needed , not necessarily frequently, as the vise should go back to accurate position when replaced on the machine.


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## tjb (Jun 12, 2020)

JimDawson said:


> I normally tram to +/- 0.0002 or better, normally takes me a couple of minutes.  Takes longer to set up the indicator than it does to tram in the vice. There is a trick to it.
> 
> I snug the the left screw a bit tighter than the right.  The set the indicator on the left side.  Then as I'm moving the table to the left, I'm bumping the vice with my hand in what ever direction it needs to go to reduce needle movement.  Then move back to the right, and set 0 on the indicator again.  Rinse/repeat as needed.  With a bit of practice you can do it in about 3 passes.  Then finish tightening the vice down. Check again if you like, but my vice never moves when I do the final tightening.


I do it the same way with about the same number of passes.  My results are consistently right on top of zero with a good DTI.  Took a few trial-and-error iterations to get the efficiency down, but it is now pretty simple and straightforward.

Jim, I think, however, you're making one fatal error in your approach: you should tighten the RIGHT screw a little tighter than the left and do everything else in the opposite direction.  It's my understanding there is solid scientific evidence that this is more accurate.  I think it has something to do with the direction of the earth's rotation.  I learned this from the same guy who told me when you're framing a building to never throw away the nails that have the heads on the wrong side.  Save them because they go on the other side of the building.  Works every time.

Regards


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## homebrewed (Jun 12, 2020)

tjb said:


> I do it the same way with about the same number of passes.  My results are consistently right on top of zero with a good DTI.  Took a few trial-and-error iterations to get the efficiency down, but it is now pretty simple and straightforward.
> 
> Jim, I think, however, you're making one fatal error in your approach: you should tighten the RIGHT screw a little tighter than the left and do everything else in the opposite direction.  It's my understanding there is solid scientific evidence that this is more accurate.  I think it has something to do with the direction of the earth's rotation.  I learned this from the same guy who told me when you're framing a building to never throw away the nails that have the heads on the wrong side.  Save them because they go on the other side of the building.  Works every time.
> 
> Regards


Unless you live in Australia/NZ?  The Coriolis Force, ya know.


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## tjb (Jun 12, 2020)

homebrewed said:


> Unless you live in Australia/NZ?  The Coriolis Force, ya know.


Whoa!  Never thought of that.  Still can't figure out why those guys don't fall off the planet.  I wonder if they ever get tired of hanging upside down all the time?


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## higgite (Jun 12, 2020)

I do what Jim does, but like tjb, I cinch the right bolt down pretty snug and leave the left one just snug. Backwards from Jim, but I’m left handed, sort of, but that’s another story. The last time I trammed my vise, I got the fixed jaw down to .0001” over its 3.5” width. Took me 4 or 5 minutes to get there, but I had coronavirus lockdown time on my hands.

Tom


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## mmcmdl (Jun 12, 2020)

MrWhoopee said:


> If it's less than one of those little lines, it's close enough.




You got that right . And my " little lines" are now on tape measures !


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## Mini Cooper S (Jun 12, 2020)

I assume that you are working with a knee mill. That said, something that you need to remember, is that those machines are inherently not capable of working to tenths.  You are in reality lucky to maintain .001" accuracy with a knee mill, there are just too many areas the will allow movement.  The X axis, Y Axis, knee, ram, turret, quill, and joints for tipping the head all impart some level of error.  If you need it that close, it needs to be ground.  As benmychree said, use fixture keys.  Set them up good and they will save you a lot on time.  I personally am not a fan of swivel vises, they are handy for angles but unless you do a lot of angles, why bother?  I have seen too many guys assume that they were indicated in and scrap a part because they weren't, or the swivel slipped under the load of a heavy cut.

Richard


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## BGHansen (Jun 12, 2020)

I tram the same way with a DTI in an Indicol holder on the spindle.  Tighten the LH side pretty tight and start with the DTI in line with the vise bolt to the table.  Then sweep to the RH side and adjust the RH side to the LH number.  Theoretically, I should be really close in one pass if I was in line with the LH bolt.  Usually get better than 0.0005" in one pass back and forth.

I use gauge blocks from these sets in the vise(s).  Use an 8" one in the Bridgeport's 6" Kurt.  Use a 20" one when tramming in my Tormach's twin vises.  Works pretty slick on the Tormach's Glacern vises.  I pin the gauge block to the fixed jaws with a 2" length of Delrin which leaves access to the 1/2"-13 vise clamping bolts.  Tighten up the vises on the block, snug up the LH vise LH screw and start to sweep.  Get to the RH side of the RH vise and adjust to match the number on the LH side.  Snug down the cap screws and am usually better than 0.0005" with one pass back and forth.

Bruce


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## Buffalo21 (Jun 13, 2020)

I’m waiting for the device that you clamp into the vise and the high quality NASA/Military grade GPS tells me its right.............


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## ddickey (Jun 13, 2020)

I use a 12" ground parallel in the vise just so it's barely snug. Tram as normal.


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## higgite (Jun 13, 2020)

Buffalo21 said:


> I’m waiting for the device that you clamp into the vise and the high quality NASA/Military grade GPS tells me its right.............


I keep it simple. I hire a surveyor. 

Tom


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## Asm109 (Jun 13, 2020)

I am right handed and the access to the right handwheel is better on my mill.
I snug the right side vise bolt and just barely snug the left. I intentionally slew the vise so the left side is away from me.
Indicator starts on the right side of the fixed jaw.
I have a soft face hammer in my left hand.
Start cranking the handwheel and tapping the vise while watching the indicator.
Because of the location of the pivot point the indicator reading when it is perfect is 4 or 5 thousandths higher than the initial reading.
Keep cranking and tapping and before I am halfway across the vise the indicator is barely moving. A few more gently taps and the last inch of travel has no motion.
Reverse direction and see how close you are.  If it is around .0005 I call it good. If I need better I take one more pass.
Snug the left bolt more while watching the indicator for motion.  With a good Kurt vise it never seems to move.  Old worn out vises, sometimes.
Done.  Takes longer to get the indicator into a collet and lined up with the jaw than the rest of the exercise.


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## Mitch Alsup (Jun 13, 2020)

I usually only tram to 0.000,5. When I need to tram better than that I use a parallel because the faces in the jaws have 0.000,5 scale bumps in them.
But my vise is sitting on a 10" rotary table, so I can tram without undoing the bolts and knocking the vise around, much faster.


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