squaring a vice for newbs

[DerHammer]

I have been trying to square my vice off of some large aluminum stock which has two factory edges. The stock is about 18" long so I figured as long as The vice jaws are clamping the two factory edges, then the part should square with the vice right? So far, the results have been unsatisfactory because it seems like no matter how close it looks at the time, the next stock doesn't square up when tightened down like the previous. I have tried to take the same strategy to fixed side of the vice jaw itself thinking maybe there are variations in the stock even despite being factory cut, but it seemed to have the same results when clamping in the next part. On top of that, it only gives me 6 inches to throw off of when my parts are 18 long so one or two mill off there translates into allot at each end.

What tools do I need to properly precision square my vice? I noticed somebody mention a dial indicator on another post but I'm a little confused where to mount the indicator so that its fixed and also how I'm supposed to get the probe to reach the edge I want it too. The parts I'm cutting are large as previously mentioned, so I have my Jaw caps moved to the outside of my vice, which is pushing my cross travel "Y axis" to its max. Leaves me about .5" on each side of the part to run past with an endmill. I don't see any way to attach a larger tool to the quill and run past the edge of my part far enough to indicate it? Can somebody plz explain how a dial indicator is supposed to be used to square a vice in the X,Y plane before I turn to drinking?

[wganders]

If you're trying to square up your vise with bar stock you would need precision ground stock. All sides will be square and parallel. But, I'm not sure what you mean by squaring up your vise.

If you're using a Bridgeport type of mill, you need to tram the spindle to the table. Get an Indicol with a dial indicator, clamp the Indicol to the spindle and sweep the table. All you should have to do with the vise is indicate it in so that the fixed jaw is parallel with the X axis.

If the parts are too long for a 6-in vise I usually use two vises, side-by-side.

[msomerville]

You should be able to put your indicator straight into a collet. For instance my Starret indicator has a 3/16ths shank on it. Put a 3/16ths collet in your machine and tighten your drawbar until the indicator is held firmly. Run your table back and forth (left to right) until the needle on the dial indiacator reads the same all the way across the fixed jaw of the vise. Make sure you have your table locked (if it is a manual machine) obviously not in your x axis but y axis along with your Z.

[DerHammer]

Thanks for the info, I suspected that there might be some variation on the stock, so ill go back to squaring off of the vice. It just doesn't seem like 6 inches of vice is enough to square off of when I haft to throw up to 18 inches at times for my parts. It is a knee mill, but its a rigid column mill so if I'm understanding what tram is correctly, I cannot adjust mine. When I face my parts it leaves lines behind about .001 high, just enough to feel so I suspect thats about how much the tram is off. There is no joints or pivots whatsoever on my column so I guess its something I just haft to deal with. Its similar to the old Boss Bridgeport's mills for those who are familiar with them.

So going back to the vice, I really only have control over how square it is with the travel of the machine in the X,Y plane. I use end mill holders similar to a CT40 that tighten up via a power draw bar thus I don't use your standard Bridgeport R8 type of holder. So, what I'm still unclear on is, how one would lock the Z,Y axis and what exactly an indicol is? Also, from what Ive read on other threads, you don't want to clamp and indicator to a tool holder like that do you because it can rotate as your jogging right? I'm new to this so I haven't actually ever seen a dial indicator used to do this before in person.

[Mitsui Seiki]

Here's a pic for you.

[under-dog]

Please note that this is a very generalized statemant as I am not farmiliar with your mill......


If you are getting a steps indicating that the tram is off in the y direction and you have no adjustment on that for your machine in that direction then you can try shimming (may take only a sliver of paper) at the pivot of your column or where the spindle head attaches etc. I have seen many reccomend this technique. But like I said I am not farmiliar with your machine and what is truly meant by "rigid"


I was lucky as my Taig seemed pretty dead on and did not require shimming

[DerHammer]

thanks for the info. I might be reading into the picture too much, but it looks as though the probe of the indicator actuates by a swing/lever rather then a push button style, which I previously assumed was a standard for dial indicators. Am I looking at this right and if so, what is this style of indicator called?

[Mitsui Seiki]

Precision Dial Indicator

[Geof]

Originally Posted by DerHammer thanks for the info. I might be reading into the picture too much, but it looks as though the probe of the indicator actuates by a swing/lever rather then a push button style, which I previously assumed was a standard for dial indicators. Am I looking at this right and if so, what is this style of indicator called?

Your interpretation is correct. There is a little lever and the dial has a very limited travel of about +/-0.030". The lever has a slip clutch so it can be moved around through about 180 degrees allowing the dial to be positioned to be seen easily but have the probe contacting the part being measured. This little thing is called a Dial Test Indicator.

[djr76]

Ive seen them as low as 50$ in the J&L catalog. Its a must have tool for machining.

[msomerville]

If you only spend $50 expect to replace it in a few months. Although you may not use it that much and it may last you forever. I would look into the test indicator rather than the plunger style. This will enable you to swing centers on holes where a plunger style would be too thick to get into the hole.
If your machine uses servos for travel in X & Y than you wouldn't need to lock your table.
No need to rotate your spindle just jog back and forth like you see in that picture.

[LeeWay]

Something else you could do once it is trammed our is to add precision blocks to the bottom of the vise so it will sit tight in the table slots. Some vise have little alignment blocks. Then make some softer jaws for the vise and let the machine mill them out. Either a step on the top ot most of the face of the new jaws. This is what I have done and it always sets up without issue and dead square to the table.
You can make a sub base out of a little larger material and leave it mounted on the vise base. You would be able to add more mounting blocks to it or even bars to catch more than one table slot. This is assuming the table slots run perfectly parallel to the travel too.