Vices

(no, not the pachinkonudenoodleparlour nakedopiumlash kind)
Looking for vises for two milling machines, an X3 and a smaller BCA. Any tips?
For instance, what size - what kind, would a good drilling vice do or do I need a machine vice - is swivel/tilt useful and does it affect accuracy -
Looking at http://www.chronos.ltd.uk/cgi-local/sh000001.pl?REFPAGE=http%3a%2f%2fwww%2echronos%2eltd%2euk%2fcgi%2dlocal%2fss000001%2epl%3fpage%3dsearch%26SS%3dparting%26search%2ex%3d0%26search%2ey%3d0%26search%3dACTION%26PR%3d%2d1%26TB%3dA&WD=vice&PN=New___Precision_Vices_from_Soba%2ehtml%23a110070100#a110070100
would the 100 mm Heavy Duty Drilling Vice be suitable for an X3? Or would the Soba 100 mm Low Profile Machine Vice be better, and is it worth the difference?
Any tips welcomed, even newbie ones, I haven't done a lot of milling.
-- Peter Fairbrother

On Wed, 03 Mar 2010 02:44:34 +0000, Peter Fairbrother
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Personal feelings 1 Do not touch a "Drilling Vice" for your mills 2 I would not bother with a "Swivel/Tilt" it will probably affect your headroom too much. I have never needed one "Yet". I do have one that I bought New for £9 but it needs alot of work to make it in any way accurate. A back burner project. 3 For the X3 a 100mm wide for the BCA an 80mm or smaller 4 Check opening capability. Useful if you can fit jaws to back sides of vice and opening part 5 Long work can always sit on 123 blocks but gripped in middle
I have an 80mm cam lock vice. The back jaw has horizontal and vertical V grooves dependent on how fitted. Very useful. I have done everything I needed on my X2. It all depends on what you want to make! Think that through before a decision. Make a set of thin (1/8") parallels of a range of heights say 100mm long. Soft is ok but grind them.
Good luck.
Richard

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Peter,
I mostly agree with Richard's comments - no. 1 emphatically so. I have 2 swivel/tilt vices, which I don't think I have ever used on the milling machine but are very useful indeed on the T&C grinder (which is what I bought them for).
Watch jaw opening - some even quite big vices have rather poor opening lengths, the Soba ones you looked at were quite reasonable. Just occasionally (in my case, about twice in 25 years) I have been glad to have 2 identical vices to hold some very long material, but if I hadn't had the extra one I'm sure I would have bodged it some other way.
As for making parallels, they are available so cheaply I question whether it is worth making your own; if you don't have a surface grinder, emphatically so. However, if you do, I suggest getting hold of some gauge plate (ground flat stock) and chopping out some pairs of this of length about equal to the jaw width - saves grinding for accuracy, and also you can use some thicker stuff, easier to balance the work on.
David

On Wed, 3 Mar 2010 11:37:13 +0000, David Littlewood
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The main reason I suggested making parallels was that most offered are 6" long which with a jaw width of 80mm maybe, can make them awkward to use. Also for someone new to milling it is a simple excercise. Also "soft" parallels are a good option for a milling newbie IMHO.
Richard

Thanks, all.
To summarise: swivel/tilt isn't much use - parallels are good - 100mm with a decent opening range would be okay for an X3 mill - and last but not least, don't buy a drilling vice, I need a milling vice.
What's the difference between a drilling vice and a milling vice?
Would a "Precision Tools Vice" like the ones at http://www.arceurotrade.co.uk/Catalogue/Workholding/Machine-Vices
be of any use in a mill?
Thanks again, and sorry if these are newbie questions. If anyone has a pointer to a page on the different kinds of vices ..
-- Peter Fairbrother

On Wed, 03 Mar 2010 13:00:06 +0000, Peter Fairbrother
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A proper milling vice will locate the moving jaw fully. Not an option on the Drill vice.
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Many people use this style BUT 1 How are you going to clamp it to the table? No grooves on the sides on these shown. Mainly used for use on a Mag Chuck on a grinder. 2 More fiddly for changing the opening.
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Oh by the way DO NOT drill through the job into the base of your new vice. You will not be able to say "the dimwit that had it before me did that" <G>
Oh yes an one sharp tap with your copper or hide hammer will settle the job down onto the parallels. Tighten the vice first do not tighten after tapping down. Oh yes and deburr after every op. Not chamfers just deburr, leave all corners square until you decide to chamfer. Thats my opinion anyway. Richard

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I think the holes in the side are for holding down - but don't have one, so anyone who does could comment on how convenient this is.
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That would be really clever, I wish I knew how you did that. I reckon that if the vice is loose enough for a copper hammer to move it into place, it's certainly loose enough for the impact of a milling cutter to move it out again.
Peter, I would ignore that suggestion. I tighten my vice to the point where I can't move the work by hand, tap down, then give the final turn of the screw to tighten. If your vice moves work significantly on tightening, it isn't really up to the job of milling. There are ways of improving this, such as adding an extended bottom plate, but a good milling vice should not show any significant movement.
BTW, the reason for the "more fiddly" way of opening/closing the vice shown is that it puts the thrust in such a way as to force the moving jaw, and the work, down into tighter contact with the base.
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Again, I wish I knew how to be sure I had deburred the corners properly without leaving at least the smallest witness line of a bevelled corner.
David

On Wed, 3 Mar 2010 15:55:43 +0000, David Littlewood
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I do not have one either but I always assumed that the holes were associated with the movable bar the the loose jaw is screwed down to.
I have noted (from reading posts) that some types are fiddly in that the screw sometimes loses the bar and getting it back in is a pain. I understand people have added springs.
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AFAIAA Not all milling vices will pull the loose jaw down whilst tightening. The action of tapping the job down IMHO is to settle the jaw down as much as the job. I know with my vice that after tapping down the parallel is solid. If I subsequently retighten then the parallel will become loose. I obviously have a crap vice <G> but it works for me.
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Define significant <G>
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Aw come on there is a hell of a lot of difference between a chamfer and a witness line. My initial point was that deburring as you go will stop errors in subsequent operations. I am sure you will agree that assembled jobs always look better if chamfers are only on the outside corners not corners adjacent to faces. If a newbie gets into the sharp corner habit (with witness) from the start his work will look better.
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Richard

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They are indeed. Actually, on looking more closely at the picture, I see the larger 3 have what look like holding down slots at the ends. The smallest one however seems only to have the side holes, which are in any case not in the right place to be for the closing screw. No point in speculating more, we need someone who actually has one to know!
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OK, responding to the challenge, I went to the workshop and put a block of steel in my milling vice resting on 2 parallels (about 3/4 the depth of the jaws. I used a DTI calibrated in microns to measure the deflection of the top of the MS, starting with the vice gently hand-tightened (not possible to move by hand, would move with copper/hide hammer tap), then after a good stiff tighten (wouldn't move even with a decent tap).
It was impossible to be consistent in my tightening, but next to the moving jaw the movement ranged from 2 to about 12 microns, mostly 4-6 microns, but a bit more if my first tightening was sloppy, and usually zero or near zero next to the fixed jaw.
To put this in context for those for whom microns are strange, 10 microns is 0.01mm, or 0.4 thou. Most people would struggle to measure that consistently, especially without temperature correction. Equally important, it is the *only* way to be sure the work is firmly down. I am always reluctant to hit things when they are in contact with a sensitive DTI, but giving the MS some modest sideways taps with a copper hammer after full tightening showed absolutely no deflection at all.
What I actually do, when it is critical, is to gently tap down with the hammer at the same time as tightening the vice. I'm sure if I had ever had an occasion when the small deflection mattered I could fettle the vice (an Emco job that I bought with my FB2 mill) a bit to reduce it.
BTW, the *backward* movement of the MS on tightening the vice was quite shocking - up to 20 microns - showing how much the vice was distorting itself. This was with no card or paper between the work and the jaws; with card shields the lateral movement could be greater.
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OK, I don't think we are saying anything materially different here.
David

wrote:
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Generally, drilling vices are made with movable jaws that can swivel slightly to hold non-square work and that are often rather loosely attached to the slots/holes in the vice body. This means that the jaw can tilt and lift up when holding work. You don't want this if you are trying to hold work in a known position. Doesn't matter on the drill press, because you move the vice by hand until the work is in the right place. Milling vices normally have the moving jaw accurately gibbed to avoid swiveling and either gibbed to avoid lifting or with mechanisms that actively pull the down (e.g. Kurt Angle Lock type etc). They are also, much more solidly built than yer average drill press.
You can, of course, get hold of a lump of cast iron bar and make one from scratch. It's a fun excercise:-
http://www.test-net.com/milling.jpg
That one needs finishing. but works very well as is. It looks tatty, but is vastly more rigid and precise than my import 100mm milling vice.
Mark Rand RTFM

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However as we have "amateur workshops" many of us will find ourselves in the postition where, to do a particular job, we will need to use an unsatisfactory vices to hold the piece of work. One dodge I learnt from an old hand was to put a length of rod (eg silver steel - drill rod I think it is called in the USA) between the work piece and the jaw that tended to rise. As it is tightened the jaw rises causing the rod to rotate which pushes down the workpiece on its other side.
Of course if the vice is a bit light weight then use a sharp cutter and take light cuts.
Alan

Mark Rand wrote:
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Thanks.
Just so happens, I have a suitable lump of cast iron, some acme bar and tap, and some ground flat stock ...
I can probably manage the rest, I think, but how did you make the slides?
-- Peter F

wrote:
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It's childishly simple. Can't find the drawing I made it from, so I popped out to the shed and took some pictures of it. They should give you an idea:-
http://www.test-net.com/milling-vice /
The screw is 1/2"x10 acme. The tapped hole in the base was made with this:-
http://www.test-net.com/tap.jpg
Note:- It's twisted at the end because some pillock didn't harden it all the way up and, being a bit crude, it took a bit of torque :-(
There are no gibs, I didn't expect to ever use it enough to wear out. Although the slipper plates that hold the top onto the base can obviously be re-made, or ground if they wear.
The 3/8" holes in the centre section (one with a dowel in it) align with the T slots in the Myford vertical slides, so the whole lot can be firmly held with two screws. You have to open the jaw to get at the clamping screws. This was deliberate, it's as large as will fit on the Myford slide and no space is wasted!
If you do something like this, aim to remove most of the metal from the base with a drill, rather than by milling it. The metal removal rate of a small drill is vastly superior to that of a small mill. If you chain drill around the area to be removed, you even get a usable piece of scrap out of it.
regards Mark Rand RTFM

Mark Rand wrote:
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Thanks mark for that, most informative.
I'm still thinking about it, but one immediate question - how did you get the vice face square to the base / it's travel?
Thanks,
-- Peter Fairbrother

wrote:
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Milled it using the same setup for each direction. end of cutter for bed, side of cutter for jaw. Cast iron will clean up very well on a light cut, even with a lot of cutter engaged.
Mark Rand RTFM

On Wed, 03 Mar 2010 07:35:19 +0000, Richard Edwards
I'd second that.
Regards, Tony

Hi Guys, About this tapping things down in a vice. I have a Vertex K4 and recently did a little experiment with parallels. I put a block of MS in the vice, sitting on parallels and then tapped it down with all of my various hammers as I tightened the vice. I tried copper, hide, dead-blow, nylon and rubber faced and I found that all but the rubber one bounced the MS off the parallels.It appears that, anything but rubber, sends a "shock" wave through the MS and the parallels which reverberates and loosens the work. As a further test once the work was firmly sitting on the parallels, I tapped it down with the copper and the parallels were once again loose. Make of this what you will. T.W.

wrote:
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I tend to use a hide hammer but have mastered a dead-blow technique. I aim for a point somewhat below the part and continue to push the hammer down as it hits, rather than the normal hammering technique that tends to lessen the force as the blow is struck. It's almost like pushing the hammer through the part...
Mark Rand RTFM

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You can even get "dead-blow" hammers that contain lead shot in the head, which are supposed to avoid or reduce this effect. I have one, they certainly work on cabinetmaking, never actually tried it under test conditions though.
David

How many times am I going to have to explain this?
To hold a job down on to parallels in a milling vice you can use 'pull-downs' these are parallelogram section strips (mild steel) used either side of the job like this:
_____ _________ ____________ | |____ | | ____| | | |\___\| |/___/| | | | |_________| | | | |______|_|___|_|______|____________|__ | | |___________________________________________|
(again, for the stupid, you have to use a fixed pitch font to view it)
In this diagram the offset between the pressure points is exaggerated, it obviously has to be small enough for friction to hold it.
A bit of support under the pull-downs, near the jaws, helps while you get things set up - unless you have 3 or 4 hands. Once you have enough grip to hold things, remove the supports. Using this technique the only thing about the vice that you need to rely on is that the base is flat. Everything else can be knackered.
Bits of round bar will *NOT* work the same way. They would just act as a roller bearing.
If you want to make one side square to another you take out the pull-down between the job and the fixed jaw. Then you could use a round bar the other side.
It is part of the skill of a good machinist, knowing how to get good work out of worn machines.