# Machining A Vise Square



## lpeedin (Sep 24, 2015)

I purchased a new milling machine a few weeks to step up from my mini-mill that has served me faithfully.  When I did, I went ahead and got a larger vise to suit the new mill.  The vise was relatively inexpensive so I didn't expect it to have Kurt quality.  However, I found that when milling a pice of stock approx. 6" long, I was getting approx. .004 - .005" of variation along the X axis, which is a little more than I would accept.  I was getting approx. .002" of variance along the Y axis over 4", so that wasn't too bad in my opinion.  

I figured that now with my bigger mill, I could mill the vise flat.  I proceeded to flip the vise over on its ways, clamp it down lightly, just enough to hold it, and milled the bottom.  Then I stoned the bottom.  What I found is that when I flipped the vise back over, I had the slightest amount of rock in the base.  I could still fit a feeler gauge approx. .0015" thick under one corner.  

So, I lightly clamped the vise down and milled the ways. Then flipped it over and checked.  Same thing, there is a slight rock.  I then checked my mill table, and double and triple checked the vise.  It appears that the vise is flexing ever so slightly when I clamp it down and this is transferring into the cut.  

So, with the vise clamped lightly.  I actually hand scraped everything and stoned the ways again.  Now I am within .0005" in both axis'.  But, when I unclamp it, the vise springs back and then there is .002" or more deflection.  

I was thinking of using a feeler gauge to check where the base doesnt meet the table, then install shims as needed to insure the base is held flat when I clamp it down lightly.  Then mill the ways.  Then flip it over and repeat.  Anybody have any other suggestions? 

Thanks,


----------



## Vladymere (Sep 24, 2015)

Have your trammed your mill to the table and then the vise to the head?

Vlad


----------



## Andre (Sep 24, 2015)

The vise sounds like it's springing because the vise bottom isn't flat. When clamping it you deform it flat, mill everything parallel, then when it springs back everything goes wonky.

1. Don't clamp anything, scrape the bottom flat.
2. Make sure there is no rock anywhere on the mill table
3. Clamp the vise down lightly and dust the surface of the ways
4. Un-clamp the vise, bring it over to the surface plate and see if everything is flat and parallel.

If there is no rock after your good to go, stone the milled surfaces and tram your vise in.


----------



## kd4gij (Sep 24, 2015)

That is a good job for a surface grinder. That is how I did mine. But most don't have one.
The problem on a mill is unless you have a fly cutter large enough for 1 pass cut. The mill would have to be trammed  dead nuts and that is almost impossible


----------



## lpeedin (Sep 25, 2015)

Mill is trammed. Head to column, column to table. Not sure hot that would have any effect on the vise being square? The only issue an out of tram mill would ha e is that it would leave ridges with each pass of the end mill. 

Scraping the whole bottom is beyond my capabilities.  I wish I had access to a surface grinder, then this would be a non issue.   Anybody in central North Carolina have a surface grinder I can use?


----------



## Andre (Sep 25, 2015)

kd4gij said:


> That is a good job for a surface grinder. That is how I did mine. But most don't have one.
> The problem on a mill is unless you have a fly cutter large enough for 1 pass cut. The mill would have to be trammed  dead nuts and that is almost impossible



You might leave slight ridges between cuts but the entire area will still be flat. A flycutter is just a larger endmill, whatever problems you have with an endmill your going to double, triple, or quadruple the error using a flycutter.


----------



## Andre (Sep 25, 2015)

3dshooter80 said:


> Scraping the whole bottom is beyond my capabilities.  I wish I had access to a surface grinder, then this would be a non issue.   Anybody in central North Carolina have a surface grinder I can use?



You don't /have/ to scrape it flat. You can mill it, but be very methodical in how you hold it on the mill table and make sure it doesn't flex in any direction.


----------



## chips&more (Sep 25, 2015)

Andre said:


> You might leave slight ridges between cuts but the entire area will still be flat. A flycutter is just a larger endmill, whatever problems you have with an endmill your going to double, triple, or quadruple the error using a flycutter.


Very true Andre! You are much better off taking narrow passes with an end mill. Both the end mill and fly cutter will leave there own undesirable finish. But when using an end mill the project should have a flatter overall in plane result. A surface grinder or Blanchard grinder would be nice to have right about now…Dave


----------



## mattthemuppet2 (Sep 25, 2015)

could you also be relieving stresses when you remove metal? That might result in a warp too? It seems like one of those tricky problems where you need one surface to act as a reference to get another surface right, but you can't get that original surface flat.

as a general question - is there any way to blue the bottom and then carefully shim and clamp so that you have the base in its "natural" state on the mill table? I.e. if you know that the center is 0.005 high and both sides are the same, could you clamp it so that you use a DTI in the quill to make sure when clamped down the center is still 0.005 high and both sides are the same? Then if you take that off 0.005 off and reblue, the base should be mostly flat. Is that feasible?


----------



## lpeedin (Sep 25, 2015)

mattthemuppet and Andre, both of you are thinking along the lines of what I was thinking.  I figured that the ways have the least amount of surface and they will sit very well length wise on my mill table. So I was going to flip the vise over on the ways and then use a feeler gauge to identify gaps that could use a small amount of shimming so that when the vise is lightly clamped, I wouldn't torque anything.  But I like your idea about bluing the bottom.


----------



## hman (Sep 25, 2015)

3dshooter80 - You said, "I proceeded to flip the vise over on its ways, clamp it down lightly, just enough to hold it, and milled the bottom."  I have the feeling the clamping itself might have caused some warpage.  

Perhaps you could machine a "known square" block of steel, a little bit taller than the depth of the vise jaws, a couple inches wide (so it will span at least two of the T-slots on your mill table) and at least as long as the jaws.  If possible, you could even have it surface ground. Secure the block to the mill, then invert the vise over the block and tighten it.  This should guarantee that the vise ways are parallel to the table under "in use" conditions.  Then do a careful job of milling the vise base surface.


----------



## John Hasler (Sep 25, 2015)

Are you certain that your mill table is not only trammed, but flat?


----------



## Andre (Sep 25, 2015)

chips&more said:


> Very true Andre! You are much better off taking narrow passes with an end mill. Both the end mill and fly cutter will leave there own undesirable finish. But when using an end mill the project should have a flatter overall in plane result. A surface grinder or Blanchard grinder would be nice to have right about now…Dave



Eh, id rather have a milled surface on the bottom of my vise. More grip! Especially when there's oil in the equation. Imagine driving on drag radials in the winter. 

If you do want it smooth however, you can use an oil stone. Once the milling marks are gone in one spot move on to the next area, all the milling marks should be basically the same depth so use the scratch marks as a stoning guide. I've had good luck doing that, and it should be just about as flat after stoning.


----------



## Andre (Sep 25, 2015)

hman said:


> 3dshooter80 - You said, "I proceeded to flip the vise over on its ways, clamp it down lightly, just enough to hold it, and milled the bottom."  I have the feeling the clamping itself might have caused some warpage.
> 
> Perhaps you could machine a "known square" block of steel, a little bit taller than the depth of the vise jaws, a couple inches wide (so it will span at least two of the T-slots on your mill table) and at least as long as the jaws.  If possible, you could even have it surface ground. Secure the block to the mill, then invert the vise over the block and tighten it.  This should guarantee that the vise ways are parallel to the table under "in use" conditions.  Then do a careful job of milling the vise base surface.



That's probably where the warpage is coming from. 

When clamped, you have tension on one side not the other, so the non tensioned side till bow hollow in the center. When the vise is clamped down to the mill table, with bolts in the CENTER of the vise, the clamping bolts prevent it from bowing and hold it flat to the table. 

Maybe I'm overthinking things, because if you have a swivel vise it's not directly held down.


----------



## RJSakowski (Sep 25, 2015)

If you have a 2-4-6 block, you could mount it on the table and use that as mount for the inverted vise.  That way, the floor of the vise is parallel with the table and the 4 x 6" provides enough distance to minimize any error in mounting.  Make sure that you tap it in after closing the jaws in case the vise rides up when tightening.

Bob


----------



## mws (Sep 25, 2015)

hman said:


> I have the feeling the clamping itself might have caused some warpage.
> 
> Perhaps you could machine a "known square" block of steel, a little bit taller than the depth of the vise jaws, a couple inches wide (so it will span at least two of the T-slots on your mill table) and at least as long as the jaws.  If possible, you could even have it surface ground. Secure the block to the mill, then invert the vise over the block and tighten it.  This should guarantee that the vise ways are parallel to the table under "in use" conditions.  Then do a careful job of milling the vise base surface.



John, you beat me to it.  I agree with hman. I have trued up quite a number of less than precise tooling. I believe they call it "Turd Polishing".  For any work holding device I first indicate on a surface plate for any way out surfaces.  Barring anything too far off I do like John said, bite a good piece of stock in the jaws and clamp that to the table.  That fixes the two way surfaces nearest the fixed jaw true to the mill table.  I then use a machinist jack, or shims, to support the other end under the screw and clamp that as best as possible so as NOT to take out any twist in the frame.  I then very lightly fly cut the bottom, a few times, until it "feels right".  I then flip it over and go from there as the DI directs.  

For angle vises I replace the pivot shaft with a longer one and clamp that in V-blocks to the table. EVERYTHING must then be milled true to that shaft's axis.  A little more touchy but again, the three point clamping to start off works best for me.  Even with the pivot as the clamped reference I still bite something in the jaws to stress the vice frame.


----------



## LEEQ (Sep 28, 2015)

Nobody has mentioned that after milling and until stress relieving, cast iron will move. Sometimes right off, sometimes down the road. Actions such as single point planning, scraping, surface grinding don't impart the stresses to the iron like milling. As it stands, until you heat treat it, you're not dealing with a stable piece. You could chase the movement forever, or make it all good only to find it changes later. One of the Moore books, Foundations of Mechanical Accuracy, describes all this in straight forward, understandable terms. Best of Luck.


----------



## lpeedin (Sep 28, 2015)

I think I am just going to buy a better vise.


----------



## LEEQ (Sep 28, 2015)

I'm right there with you. In the mean time my enco will have to suffice. I love learning about this stuff, but I hate buying the stuff I think I can afford. It all seems to be in kit form. When I win the lottery, I can buy nice tools. Then maybe work on something other than tools.


----------



## skipmeister (Sep 29, 2015)

You may want to check with the local automotive machine shops. Most used to have wide surface grinders for flywheels resurfacing.


----------



## dkwflight (Sep 29, 2015)

Hi
Since clamping pressure is the issue, think about how the pressure is applied.
I am thinking the vice needs to be clamped on strips to limit clamping pressures on the edges near the clamps,
You might consider milling out the centre section of the bottom so the clamping pressure is eliminated from the center section. Not much metal needs to be removed, just a few thou.


----------



## ronzo (Sep 29, 2015)

Surface grinding the bottom of the vise and the floor of the vise flat and parallel is the best option. Other wise if it was mine this is what I would do


Sent from my iPad using Tapatalk


----------



## mekanix48 (Sep 29, 2015)

Had a similar problem with the vice I bought here in the UK; I could measure on the 'Y' axis & found a it was out .007" over 4"  on a 2-3-4- block & out on the 'X' axis .005"... not good!  it was mounted on a swivel base so the first thing I checked out was; were the top & bottom faces of the swivel base parallel to ea. other... not!  Obviously the manufacturer had just done a quick set up before milling the faces without checking for any discrepancy & milled over the faces leaving 'tramlines' as the finish. I ran the base over some emery cloth, 400 grit, on a plate glass flat, & revealed that the base was high across approx 2/3 of the base. I proceeded to machine .005" off across the base to flatten off as much as possible, reassembled the vice & rechecked with 2-3-4 block in the jaws again... run out down to .003" on 'Y' axis, better but not good enough. Both the mating faces on the swivel were checked (blued ) & revealed that the vice base was high in the centre compared to the outer diameter... a skim of .002" was completed & faces checked again... a much better contact pattern. All was reassembled & checked again... .002" out on 'Y' axis & .0015" on the 'X' axis, checking the DTI reading on tightening & slackening the base revealed a .002" flex front to back, obviously stress factors in the cast base are having a fun time... so what to do? I ended up deciding to get the best I could considering it's not a premier no lift jaw type of vice & ended up placing some .002" aluminium fizzy drink can shim under the back side of the vice base & tightened up, ending up with a discrepancy of .001"( over 4") front to back & .001"  & on the 'X' axis over  6" parallel.

I eliminated as much jaw lift as I could by removing the bolts from the clamp plates under the vice body, replaced with studs & fitted Nylock nuts & snugged up so that the body was neatly snug up against the slides when opening & closing the vice. I took this into account together with inbuilt stress/ flex as part of the reason for the continued discrepancy overall. Considering that most retailers, UK & US, get their stock from china & these types of vices do leave a lot to be desired I reckon I've got as close as I can get so decided to call it a day... maybe Father Christmas will leave me a nice no lift jaw precision milling vice this year...  .

George.


----------



## jmh8743 (Sep 29, 2015)

skipmeister has a point. automotive shops mill heads. they must be flat. they use big surface grinders.


----------



## lpeedin (Oct 1, 2015)

Somebody asked previously if I know for sure that my table is flat.  I am questioning that now.  I built a dual dial indicator tramming aid and got it installed in the spindle last night.  I was very surprised how much things varied from one end of my table to another.  In certain parts of the table, there is a .006" variance over the 5.5" span between the two indicators.  Other areas it is dead flat, some places only .001" or .002".  This was in both axiis.  (sp?)  I am not sure what my next steps are.  For now, I am just going to make some chips, smile, and be happy I have a lathe and a mill.


----------



## John Hasler (Oct 1, 2015)

Some of that might be the table, some might be the ways.  Need to check with a surface plate to tell.


----------



## Crock (Oct 3, 2015)

3dshooter80 said:


> I think I am just going to buy a better vise.


But then you wouldn't have the pleasure of telling people how much effort you put into making your vise work right. After all we are machinists and that is what makes tweaking something and see it come into spec so enjoyable. But then I'm retired from tool making and have a mill, grinder, and lathe but I don't have to be perfectly precise on my stuff. But it's still enjoyable.


----------



## lpeedin (Oct 5, 2015)

John Hasler said:


> Some of that might be the table, some might be the ways.  Need to check with a surface plate to tell.



Agreed, hard to tell for sure what is what.  I took the whole table apart over the weekend and was surprised by the results with my micrometer.  The table itself is within .0003" tolerance on thickness at each end, with the front being approx. .0008" thicker than the rear.  Then, the middle is approx. .0015" thinner than at each end.  Since I don't have a surface plate, all I can check is thickness, not actual straightness / flatness.  

I then checked the saddle and it was within .0003" all the way around, but I discovered an issue here.  After cleaning everything thoroughly, and lightly stoning the bottom of the saddle as the scraping pattern on there was very aggressive in a couple spots, I placed it on the base ways.  Three of the four corners sit flat, with one corner, the front right when looking at the machine rising slightly.  In fact, I can get a .006" feeler gauge under with essentially no rubbing.  For some reason I can't find my .007", so I checked with an .oo8" and it goes in about 3/8".  It appears that my saddle is slightly twisted / warped.  

So, after finding that, I put it all back together.  Then I took a 12" piece of 1.5" x .5" flat bar stock and put it in the vise and proceeded to make a skim cut on each side, just enough to clean up the face.  I checked it after the cut and again, I can't check flatness, only relative thickness.  I was within .0012" over 11.5", with approx. 7" of that being absolutely dead on, then all of the .0015" variance occuring over the last 4.5" or so.  I think what is happening is that when the weight of the table shifts from the left side to the right side, the saddle is able to settle in the corner with the gap, causing the table to tilt slightly.  I would definitely like to get the saddle surface ground to clean up the bottom face before messing with anything else.


----------



## lpeedin (Oct 5, 2015)

I should also add that what tipped me off is that with the table removed, I measured the distance from the top of the saddle down to the top of the base ways and that front right corner was about .003" higher than the other corners.


----------



## John Hasler (Oct 5, 2015)

My Grizzly table had similar problems, but worse.  I was able to scrape it in well enough to be usable using a piece of plate glass as a surface plate.


----------



## JR49 (Oct 5, 2015)

John Hasler said:


> My Grizzly table had similar problems, but worse. I was able to scrape it in well enough to be usable using a piece of plate glass as a surface plate.



     John, How thick is the Plate glass that you use as a surface plate?  thanks,  JR49


----------



## John Hasler (Oct 5, 2015)

I use two 2'X2' pieces of 1/4" glass on my cast-iron table saw table.  Thicker would be better, but it's what I've got.


----------



## jmh8743 (Oct 9, 2015)

might look at this, unique approach to "is it "square?"


----------

