Precision Tool Vice Type 2

I have had an issue with a 90mm Type 2 milling vice damaging the table. This is a very accurate vice with good capacity. Mine however has caught me out twice now through the tightening bolt touching the table and causing crescent shaped dents.

After the first time I chamfered the bolt end slightly, which did not take any thread away but just removed the ragged end. I checked this provided enough clearance or at least I thought it would. I flagged the issue to Arc who replied that they had no issues reported and would not take action until they had three reports.

Having used the vice for a while longer it has now bitten the table a second time. I can only presume some wear or bedding in has used up the clearance. Any shortening of the bolt may require remaking the nut with more thread on the upper side and shortening the spring. I could have avoided both events if I had positioned the nut in the next groove, however keeping track of where you are in the available travel at each nut position is difficult as the nut is hidden and the change in key angle is small.

Has anyone else had this issue ?

(On both occasions I am quite sure the nut was properly located in a groove)

Hi Phil,

I have a Type 1 vice from Vertex and I have had no issues with mine. Type 2 is slightly different, a photo of the underside might be an idea.

Thor

Edited By Thor on 19/11/2019 04:56:04

Sounds like you are tightening it too much in the wrong notch, better to slacken off screw and move the bar in one notch then the screw won't go in a far when tightened

I’m bewildered, Phil

Is this the vice to which you refer ? : **LINK** ?

https://www.arceurotrade.co.uk/Catalogue/Workholding/Machine-Vices/Precision-Tool-Vices-Type-2

... if so, it would appear that all you need is a thicker [and/or better fitting] washer under the screw-head.

MichaelG.

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Edited By Michael Gilligan on 19/11/2019 08:14:10

Funny enough Michael I've just been down to look at the one I have from ARC. If I tighten the screw right up with nothing between the jaws it protrudes less than 1mm but that would not be gripping anything as the force is more vertical than horizontal. The smaller 30something wide one that I have has about 5mm between end of screw and base

Cure would be 1mm off the end of the screw o as you say a small OD washer turned up and slipped under the screw head or better still get the feel of when the bar is correctly engaged

Edited By JasonB on 19/11/2019 08:19:56

Digressing slightly: When I worked in the vibration test lab, we used cap-head screws down deep counterbores in the alloy ‘head expanders’ on the shakers. ... These were always used with properly engineered thick plain washers [which I believe to be a standard commercial product].

MichaelG.

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Edit: The general style is shown in the second image on this page

https://www.engineersedge.com/iso_flat_washer.htm

... but we typically used M8

Edited By Michael Gilligan on 19/11/2019 08:34:44

Presumably this phenomenon is only possible on the two largest sizes of vise?

My 70mm version does not appear to be able to cause any protrusion of the tightening bolt below the frame. The bolt appears to be forcing the spring against the edge of the movable jaw (ie the angle cannot be such that the bolt can point ‘down-hill’ excessively.

It also appears (but not confirmed) that the spring might well become coil-bound before any problem could arise.

Certainly a shorter bolt would avoid the issue (there should be enough thread within the tightening bar - unless the spring needs extra length to avoid becoming coil-bound?).

The only gripe with mine - apart from the more awkward/extra clamping arrangement needed, for attaching to the mill bed - is that the tightening bar needs relieving to allow the vertical V to accept longer items. Oh, and it seems to be slightly magnetised.

I’m also surprised at Arc’s alleged response of requiring 3 reports before investigating the issue.

Perhaps not the simplest of vises to operate, but I like mine, all the same.

That is the intended method of use, rather than the solution.

Our Brett tried to explain this to Phil....

Before our engineer (now retired) explained how to use the vice in the correct way to Brett (his apprentice at the time), he had similar problems.

Phils's is the first and only complaint we have had regarding this vice.

It is difficult to explain this without sounding arrogant or patronising. ARC sells enough of these vices to consider this to be a 'how to use' issue. At the same time, we are aware that some customers will fail to agree, or simply not get on with this particular type of clamping arrangement. Some of them prefer the Type 3.

To clarify the point about 3 reports... yes... ARC only considers it to be a problem - especially for this product range, if it receives 3 valid complaints in a row, 'within a short period of time', at which point we will evaluate the item to see if it is indeed a 'product fault' or something else.

Ketan at ARC.

I don't own a Type 2 Precision vice, but seeing the construction, then on then face of it, I could imagine that the screw / nut bar / moving jaw is too far from the workpiece, This would need the capscrew to be rotated too many times to clamp the work, so that it protrudes too far through the "nut". Any thread protruding through the nut is not doing anything!

As long as the capscrew has one diameter, or only slightly more, engagement when fully tightened, there should be minimal risk of damage to the threads or to the machine bed.

May i suggest slackening the capscrew and moving the bar /moving jaw forward one notch and then tightening, to see if this keeps the end of the capscrew clear of the bed?

Since you seem to be in a small minority in having this problem, then it is worth examining the the methods used to operate the device. Unless by some very odd chance your capscrew is too long. This is unlikely, since they are probably made and bought in by the thousands for this vice.

Howard

Is the problem caused by not being sure that the screw is fully unscrewed before the jaw is slid up to the work and then tightened? I would guess that losing the nut would be irritating as the vice would need to be removed to refit the nut and then need trueing again. Would it be useful to rivet the end of the screw to stop accidental release or rivet a small washer to the screw end to give a positive stop when fully unscrewed?

Mike

The end of the screw does need to go right inside the nut so anything on the end won't work and will also make it longer.

The user needs to get into the habit of slackening the screw first and making sure that it is fare enough out without undoing it too far. A 6" or 8" tee shaped key helps here as it is easier to see the angle and make sure the head of the screw has pivoted down to the bottom of the hole in the moving jaw. You then as Francis says slide the jaw upto the work and tighten.

I see Jason, it does seem to be just an issue of being careful where you start from, the long key sounds a useful tip.

Mike

IMO, the vise should be ‘idiot-proof’. If that means making it 1mm taller, to avoid this potential problem, then so be it.

Losing a mm, or so, head space on my Raglan would be quite important to me - there is precious little working space on that small mill when working-holding in the vise (hence my comment above re the vertical groove), but not important for mills with better head space.

With my 70mm version, there would be the possibility of reducing the base by 1mm or so (without the problem observed above) which would help - but probably making them to use a common clamp size is a driving force behind the design!! It does appear, from the pics, that the largest version has a deeper base (needs larger clamps) and the 70 and 90mm versions have the same base depth?

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An interesting observation ... But, I wonder :

Of all the ‘precision’ tools or instruments; how many could be classed as ‘idiot-proof’ ?

MichaelG.

“A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.” — Douglas Adams

Poke Yoke is used to try and cater for for idiots but in industry you find the idiots that begin with the letter C and even the deliberate saboteur. It can be very expensive to install vision systems to just check that glue is applied or parts fitted but scrapping a finished vehicle because it cannot be repaired is also expensive.

Mike

My line of thought is that, yes, one can screw up precision tools quite easily, but not the rest of the workpiece or another machine, as in this particular scenario.

If something will self-destruct, if used wrongly, is somewhat different to damaging third party equipment.

Admitted, there is a limit - one cannot blame the cutter when it is driven into the mill table or when it ploughs into the chuck ... so at some point there must be a cross-over. It is much like the thread on leaving keys in chucks, I suppose - spring-loaded keys are the simple answer but not the simple solution.

As the late Rudi Mischetslager used to say "Common Sense is not that common"

No matter how carefully you test your new car model before launching it into sales, someone will find how to cross the wiper blades, within a month!

I have investigate numberless new engines where the customer has omitted to fill a liquid cooled engine with coolant, or with lubricating oil!

Beware! They walk among us.

Howard