Milling Vise Alignment In 13 Seconds

Bob I have to disagree with you. Vises are ground parallel on all sides, a square in the shop should be up to snuff parallell and at 90 degrees. If not give it to a carpenter.
Tables and slots are parallel to the axis on machines. Why do you think they put key slots in Vises?
If so the machine tool is junk! I have never ever come across a table in a shop out of wack as you state not parallel on there axis!
We will have to disagree then, Mark. Nothing is machined perfectly, and tolerances can add up. I always try to measure the important surface directly when possible, and I do not trust anything to be correct as received. A single appropriate test takes all guessing away, no leaps of faith. Most work does not require extreme accuracy, and when it doesn't, then shortcuts can be taken, with often large time savings. If that type of workmanship becomes ingrained and carries over to important work, then there can and will be unacceptable inaccuracies.
 
Bob I would never put a vise square or anyhing to be machined that wasn t checked when i received it. If It s not up to tolerance I don t use it and send it back so if I come to a situation where I may have a strange setup I can trust what I am using.
Like I said if it s not up to tolerance give it to a carpenter. I was just stating the fact that a decent vise ground on all sides can be indicated in more than one surface and a table on a mill not parallel shouldn t be in the shop.
I ve checked all my kit as I always have so I can use it. I think your off on a Tangent!
 
Twenty feet is 240 inches. If the dot is 1/4" in diameter, .25/240 is about .001"/". I typically align my vise to be less than .001"/4" which would correspond to .060" @ 20 ft.

However, for many operations, .001"/" is sufficiently accurate enough and the 13 seconds mounting time is very attractive.

I wondered about the reproducibility because most laser leveling devices typically quote 1/8" inch accuracy.
Accuracy is not what you are worried about, repeatability is what you want. The accuracy number is what it can be off from perfect level. If it is perfectly repeatable then it will be fine.
 
I'm going to try to wade in here but I might get punched by both sides. :distress:

- I know of a toolmaker with 60+ years experience that has his vise set up with 1" long precision ground keyways that just fit the slots on his milling machine. He has pre-indicated in the precision ground jaws on the vise. Many hours went into this prep, and he has to force the vise down whenever he reinstalls it - but every time it is within one-tenth, end-to-end. Defrayed over the past 40 years since he made this setup, he has saved many hundreds of hours. The downside is that he has several scrape marks, where he accidentally marked the table while removing and installing the vise.

- On the other side, I also know of another machinist with 45+years experience that always indicates in his vise every time. He has made custom washers for the vise with flats on them that help him to get very close, usually within .001 or .002. I've watched him indicate the vise in in 10 seconds flat - to one tenth! No marks on the table, but a little extra time every install.

Who is right? well I don't know. I don't have the time to do all the work for option A, but one day I might. I have my own version of option B, but it takes me a minute or more to get it close.

To address the OP question -- I think the laser is fine for getting it to that .002 level. If that's all you care about, then just use that. If you always go for more accuracy, you have a good starting point. Everyone develops their own technique, and lives with the advantages and disadvantages of it.
 
- I know of a toolmaker with 60+ years experience that has his vise set up with 1" long precision ground keyways that just fit the slots on his milling machine. He has pre-indicated in the precision ground jaws on the vise. Many hours went into this prep, and he has to force the vise down whenever he reinstalls it - but every time it is within one-tenth, end-to-end. Defrayed over the past 40 years since he made this setup, he has saved many hundreds of hours. The downside is that he has several scrape marks, where he accidentally marked the table while removing and installing the vise.
I do exactly the same. I also use t-nuts that are carefully shop made from mild steel, and with all exposed edges and corners rounded over to smooth large radii. They do not mark the table if they slide on it, but I do try to keep them clear of the table until over the t-slot. The t-nuts fit tightly enough to have to wiggle and push down on the vise slightly to get them into the t-slots, and also into the slots on the bottom of the chuck when changing the vise from 90 degree mounting to longitudinal mounting and back again. I always get within .0001" by simply dropping the vise into the t-slots, and a simple light push in the known direction with the heel of my wrist when tightening it down gives zero movement of the .0001" needle over the 6" jaw travel. I no longer check the vise each time I put it on the table. I take my vise off regularly for mounting work on the table, or other tooling, and always mount the vise in a different place each time I remount it, to spread any wear over the entire table. I am lucky that the mill, a Millrite built in 1967, came to me having never been used before. It was quite grimy from sitting for decades in storage, but no rust at all, and while cleaning it up, there were no chips or scratches anywhere on the working and sliding surfaces. I am working hard to keep it that way.
 
Need a photocell on the wall connected to a beeper. No running back and forth!
 
A precion ground 24" bar clamped in my vice sure shows what a tenth out looks like. A brass hammer and some patience goes a long way for me.

FYI my machinist square gets me pretty close (+_.001) and for most of the work I do that is fine, however I can and do get 10 times closer when necessary.
 
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