Question about tramming a vertex vice on the mill

Hi, I have a Vertex milling vice with a centre hole in the bottom, so I thought I make a bushing the fits snugly in that hole, bolt the bushing to the table centre so the vive can swivel around it. Doing this I find it very difficult to tram the vice by tapping it. The dial test indicator if zeroed at centre of fixed jaw, I get it to measure negative to one end the same as positive to the other end running it from the centre left or right with it zero at centre. Trying to run it from complete left or right of fixed jaw to the other side seems impossule to tram it by tapping.

If I remove the centre bushing and just tightend the one clamp bolt slightly, I can tram it relative easy and quick to the table.

What is your opinion on this-?

Edited By Chris Mate on 27/05/2023 03:43:17

The hole is not directly under the fixed jaw so you are not pivoting the vice about the mid point of the jaws length. They are often positioned mid way to the full opening width so could be 25-40mm off.

Edited By JasonB on 27/05/2023 07:03:56

Chris

As Jason says the centre hole is offset relative to the fixed jaw so any error will produce a positive deviation on the indicator one side of the jaw centre and a negative one the other.

Swivelling about one fixing bolt the error and indicator deviation is all one way.

That said your set-up is functionally no different to having the vice on a swivel base. Generally folk have no trouble tramming with this set up so I suspect your technique isn't quite right.

My general use vices live on their swivel bases because I prefer to retain the easy swivel facility, running a Bridgeport means I have plenty of Z axis space. Frequently not the case for folk using smaller machines.

My alignment technique is :-

1) start with the indicator in the middle of the jaw and adjust the Y axis to give a sensible zero point. For ordinary set up I use a 1 thou sensitivity Verdict lever indicator in single direction mode so my start point is with the needle half way round the dial.

2) run sideways until there is a suitable deviation on the indicator, needle movement of about 1/3 of the dial works for me

3) adjust the vice to halve the error

4) go back to the middle and tweak the Y axis to return the needle to your zero point

5) move sideways the other way until you have a suitable deviation

6) adjust vice to halve the error

7) go back to the middle and tweak the Y axis to return the needle to your zero point

Repeat steps 5 to 7 on alternate sides until the error is sufficiently small for your purposes.

You may want to finish up by scanning the whole jaw width as this effectively doubles the sensitivity but you have to keep your brain firmly engaged so as to move the vice the right way.

The key is to halve the error at the outer end of each scan.

That said I rarely tram for casual work because simply mounting the vice and pulling back hard so the bolts are firmly trapped between one side of the tee slot and the opposing side of the vice mounting slots is reliable to a thou or two over the 4 inch jaw width of my usual vice. Naturally the swivel doesn't quite read zero degrees but its pretty darn close considering the bolt slots are essentially un-machined.

Consider making special plain shank, or even square shank, bolts for vice holding down and machining the vice slots so pulling back in that manner is close enough to accurate tram for ordinary work.

Clive

Edited By Clive Foster on 27/05/2023 08:19:37

Clives methid works well but i believe there is a much quicker method as follows.

I set the vice down by eye but very slightly off square with the right side slightly towards me. This is so I know which way to tap. I then put the indicator on the far left side of the fixed jaw. Then I wind the table to the left. Because the vice is not square the needle will move. I tap the front left side of the vice until the needle stops moving. It doesn't matter about readings halving things or anything I just tap until the needle stops moving and the vice is then square. With practice you can square the vice with one movement of the table and then nut it up tighter. I then wind it back again checking for no needle movement. Its normally done in 2 movements. If you want to give yourself more time to tap it square clamp a longish piece of straight flat steel in the vice and read off of that.

I'm the same as buffer, I just look for movement of the needle not a reading

Or save all the bother and machine a groove in the base of vice to mount a piece of key steel the same width as your T slots and hold it in position with two countersunk screws. To get the groove machined parallel to the fixed jaw, clamp a piece of square bar to the mill table, set up parallel to the X axis. Flip the vice upside down and clamp the jaws on to the square bar. Then machine the groove in the base.

put a parallel bar in vice put a good straight edge or 12" ruler on that, grip in vice cast your eye along the tee slot to the ruler tap until square tighten vice down, practice this and you can get a vice to within .002" by eye every time close enough for most jobs

If I remove the centre bushing and just tightend the one clamp bolt slightly, I can tram it relative easy and quick to the table.

Then why not just do it like that? Nothing like making a job hard work, just for the sake of it! Live and learn is what I suggest.

If you want to set the vice so that the fixed jaw is parallel to the movement of the table, you could make a "Goal ,post to do the job.

the base of each of the pillars should be a snug fit in the T slot, and be drilled through so that it can be clamped to the table of the mill.

Dixed to the pillars (Preferably using a Vee ).is a horizontal cross bar. This should be sited at a height which allows the vice to clamp it.

Once the "goal post" is securely in place, take a skim aloong each dise with an end mill.

When the vice is clamped to this machined face, the fixed jaw will be in the plane of travel of the table., and can be clamped down.

The "Goalpost" is then removed, so that work can begin..

Howard

Ok, this was the fastest I ever trammed the vice. I used the advice of moving it from centre to 10 point on test dial indicator in combination with my centre point adustment idea. In my case I want to tram the vice every time I decide to recheck it or removed it as good as I can without too much hazzle and no hammerring.
Method:
1-Dial test indicator attached to bottom left of Quil base, not on centre, the cutter is not removed.
2-I Bolt centre pice to table.
3-I insert vice over centre piece, and hand tight the two bolts not tight at all both.
4-I lock down the Y-Axis, and fingertight the Y-Axis.
5-I Fit two 1-2-3 blocks one on each bottom side of vice with its own T-Nut/bolts I made before so they dont move. I manipulate vie direction easily with this.
6-I then lineup the dialtest indicator at zero in the centre of the fixed jaw.
7a-I run the dial test indicator to the right till it reach 10 point. I then turn one of bolts to get it in halfway zero direction.
7b-I then run the dial test indicator left past zero and adjust to half that measure. At this point its good enough trammed, two steps of adjustment.
7c-I carefully tighten the vice hold down bolts one at a time a bit till tightened, it did not move.

The thing is turning the bolts on 1-2-3 block give you a very quick indication of needle direction without over doing it just slightly.

Thanks for all info I am happy to do this everytime. It seems in this case where exactly the dial indicator is placed on Quil bottom does not matter, and the centre bolt not under spindle centre does not matter either in a square check setup, however I am sure in other non square cases it would/may very well matter, like using a turn table.

The "Goal ,post" will align the vice within 0.001" (0.025 mm ) everytime quicker than clocking, unles you want gretaer accuracy.

Clocking and tapping can take much longer than it takes mto set up, clamp the vice, and remove the gadget.!

Howard

Howard

For 0.001" (0.025mm) level tramming by far the fastest method is to use shoulder style Tee bolts whose shanks are a smooth sliding fit in the slots with a top hat style washer made to be similarly smooth sliding fits on the shoulder bolt shank and in the vice hold down slots.

Set vice in position, slide Tee studs into the slots, drop washer over stud, wiggle til it settles down into place and pull the vice back to take up the (minimal) play whilst tightening down.

The vice does have to be prepared by re-machining the fixing slots so they are accurately mutually aligned with the sides parallel to the jaw axis. Probably nice to clean up the tops too so the washer has a nice smooth surface to sit on.

In a practical world it's probably adequate to simply clean up the slots and pull back against a standard Tee nut and stud set up. It's what I normally do when mounting and re-mounting mine, repeatability error is of the order of a couple of thou in 4 inches. Reckon if I ever did the re-machining and shoulder bolt mod I'd expect to reduce that to half a thou (ish).

Which is about as good as can be reasonably expected from a vice with permanent keys. Have to allow a touch of slack in keyed set-ups so things don't jam up if the tee slot is imperfect. Removing a keyed vice where enthusiasm has overtaken thought and a too tight fit overcome by pulling up the hold down notes tends to be frustrating and vocabulary enhancing!

In practice my tramming method is so fast when really accurate set-up is needed that it's not worth improving things.

Avoiding set-up where a minor error is likely to lead to serious and long winded rectification efforts is one of the more important of Clives "Rules for a Happy and Serene Lifestyle". Unfortunately honoured more in the breach than I would ideally choose.

Clive

Edited By Clive Foster on 03/06/2023 10:20:18

My mill bed has a swivel base, not the fixed one as usual, so I think I want to be able to tram it well every time as well for that reason, if I have a tramming issue, I must look at the swivel bed 1st, so if my method is easily repeatable and accurate, thats covered too in one go. This is how I understand this in my case. I use the swivel base now and then, and use same method getting that squared up(With two adjusting handle screws).
Maybe this is my fate to prevent overtapping of vice and/or bed(X-Axis) and waste time & effort that way.

My thinking is that if the X & Y axis are not 100% square and run not square, you will have a problem tramming your vice 100%........I maybe wrong here, what are your opinions on X/Y axis not 100% square and tramming any vice on it-?

Edited By Chris Mate on 04/06/2023 06:40:14

You are right, the X axis must be set at accurate 90* to the Y axis as a first step - the vice is just a workholding fixture, and should be set-up afterwards.

I’ve just had a peek at your Album, Chris … and found this: **LINK**

https://www.model-engineer.co.uk/albums/member_photo.asp?a=56455&p=903384

Looks an interesting and versatile machine

+1 for the comment by DiogenesII

MichaelG.

Hi, you could get your vice parallel to the cutter if your X axis isn't, but of course if you move the X axis either way, the vice will move in the Y axis in the corresponding direction. but will remain parallel to the cutter, so it would be fine using it in the Y axis as long as you don't move the X axis. Unless of course you want to cut a taper on one side.

Regards Nick.