Tramming a vise- the easy way

[682bear]

I've read several times on here where it's mentioned how difficult it is to tram a vise on a milling machine, so I decided to do a quick write up in hopes that it may help make this easier...

First, get the vise on the mill table and install the hold down bolts... do not tighten them, just snug them...

Set an indicator up in the quill... or however you would normally use your indicator... zero the indicator on the left corner of the fixed vise jaw, then lock the saddle (to eliminate error from any saddle backlash)...



Then move the table until the indicator is on the right corner and note how far it is out of parallel...



Now it is on the right side of the vise, so you want to loosen the hold down bolt on the right side and bump the vise until the indicator is back at zero...



Now snug (not tighten) the right hand bolt.

Move the table until the indicator is back on the left corner...



the vise will probably still not be perfectly square, so loosen the left bolt and tap the vise until the indicator is back on zero. Snug the left bolt.



Now move the table until the indicator is back on the right corner...

Keep repeating this sequence until the vise is as accurate as you want it... don't forget to tighten the bolts good when finished, and always double check the tram after tightening the bolts... in case the vise moves while you are torquing them.

I can usually have the vise within 0.0002" or 0.0003" the second time I move to the right corner... the entire process should not take more than 3 minutes... 5 at the most. It's quick, easy, and painless...

I hope this helps someone...

-Bear

 

[Winegrower]

There must be more ways to tram a vise than there are machinists who tram vises. Your method is good, and if speed is the issue, what I do is move the table left and right a bit while watching the indicator, and tap the vise in the direction that minimizes movement. It's surprising how quickly this converges. I like to check the other two axes just to make sure there is not a chip caught somewhere.

 

[benmychree]

Or, just install tight fitting keys in the slots in the bottom of the vise, snugly fitting in the tee slots in the table, should be close enough for nearly any and all work.

 

[RJSakowski]

Here is what I do:

1. I lightly clamp the left side of the vise
2. zero the indicator on the left side of the jaw as close to the anchor point as possible
3. move across to the right side and tap the vise to remove half the difference
4. move back to the left side and repeat 2, 3, and 4,
5. Lock down the right side and tighten the left side clamps
6. Recheck alignmnet

The error after steps 2 and 3 arises because the left zero point isn't above the pivot point but amounts to around 10% of the error before correction. You can use "Kentucky windage" to allow for the error. Usually, no more than two iterations are required.

 

[RJSakowski]

Or, just install tight fitting keys in the slots in the bottom of the vise, snugly fitting in the tee slots in the table, should be close enough for nearly any and all work.

I use the keys also. It is close enough for most work bur for precision work, I will sweep the vise. I habe learned the hard way not to assume alignment. One little chip can do so much damage.

 

[Doug Gray]

Second the tap as you go methode.

 

[Suzuki4evr]

Second the tap as you go methode.

I concur

 

[homebrewed]

The need for an iterative procedure arises if the measurement points are not coincident with a pivot point. So (say) when you bump-zero the indicator when it's on the left side, the right side of the jaw also moves. On my flat vise the hold-downs are very close to the left and right sides of the vise jaw so I can get to under .001" with just one pass. That's if I start out with the DTI as far right (or left) as possible.

On the other hand, I have a tilting vise whose hold-downs are significantly further away from where I can place the DTI so it takes a number of passes to get into tram. It doesn't help that the only way I can mount it on the table is with the jaws parallel to the Y axis, but the hold downs are spaced apart on the X axis. About worst-case for ease of tramming. To make it a _little_ easier I usually place a 123 block in the vise and indicate off that, but, still, the measurement points are a significant distance away form the hold-downs.

 

[T Bredehoft]

But if you happen to have a parallel that lets you position the indicator over the hold down bolts....

 

[mmcmdl]

Tramming the vise should take no more than a few minutes as bear said . My only addition to his post would be , if you have a power feed on the x axis , throw it on and bump the vise while traversing . Pretty simple to dial it in in a minute or so .