My vise isn’t at 90 degrees

[moonmanParticipant @moonman]

So I have a cheap vevor vice on my mill, it’s the 4″ model and until today I was quite happy.

I noticed today that things just aren’t coming out square, not good. So I broke out the DTI and got to work expecting to find something out of tram.

However I found this:

I know there is debris on the vice but no amount of wiping clean changed things, I really do believe it’s out square.

I am a novice at this sort of stuff and I don’t have the cash to go get a top end vice. Where do I begin in rectifying this issue.

Thanks

[bernard towersParticipant @bernardtowers37738]

if the jaws are parallel in all planes then a very light cut from the body should improve things

[David George 1Participant @davidgeorge1]

If you measure the gap with feeler gauges remove the jaw face clean and stone the faces and put some shim betwen the jaw and the slide or fixed body which can be held in place whilst you replace the jaw with a little grease. It will remove any play in the jaw. Have you checked that the bolts in the strip which holds the slide down are tight as well before checking squarnes.

David

[not done it yetParticipant @notdoneityet]

Warning to others:  l have bought some items from vevor – but only in the knowledge that I can fix them if/as necessary.

[not done it yet]

On not done it yet Said:

Warning to others:  l have bought some items from vevor – but only in the knowledge that I can fix them if/as necessary.

This is kind of what I expected, I’m just double checking on the best way to go about the repair.

My idea was shimming, I’ve taken the jaw off and can’t believe how bad the casting is under it.

They are still a bargain vice though, other than this error which is fixable I do like it.

[Pete.Participant @pete-2]

Is it the jaw or the casting that has the problem?

[Chris CrewParticipant @chriscrew66644]

Back in the days when criticism of far eastern products was more than justified I bought a cheap tilting vise. I subsequently found that nearly everything about it was out of truth so I squared up all the surfaces that mattered and put bushes in the pivot point. The castings machined nicely and appeared to be of good quality cast iron. Far eastern products have greatly improved over the last 30years so I think you may have just been unlucky.

[Neil LickfoldParticipant @neillickfold44316]

Clamp a Parallel bar in the vice. Then see how much out of square it is. It may also be possible that the rear jaw base, is not clean or some other issue or bur etc. Edit,  to clarify, the fixed Jaw needs to be investigated.

[bernard towersParticipant @bernardtowers37738]

I personally think shimming is a waste of time for something that is going to do a lot of work ,far better a permanent solution by by machining dead square and vertical. Also check all bolt holes are well deburred.

[martin haysomParticipant @martinhaysom48469]

how square is the square ? is it the jaw or could it be the base that’s not right

[Clive FosterParticipant @clivefoster55965]

According to a reliable contributor on one of the Practical Machinist Forums vices the fixed jaw on vices with that general style of bolt down mounting tend to lean back slightly at the top under clamping loads. Apparently even proper professional vices, such as Gerardi, can have a small, but still measurable when Inspector Meticulous is in full supercharge mode, deflection. So things may not be so bad under load. Pop something in it and use a lever indicator to see if things shift.

Obviously you have checked that the jaw plate is parallel and true.

What is the alignment of the moving jaw like?

If the moving jaw is true and the fixed jaw block seats well enough on the body consider applying smear of JB weld or similar metal loaded filler on the fixed jaw body before loosely inserting the jaw plates and lightly clamping the vice up squiggling excess filler out whilst bringing the jaws into mutual alignment. Grease or cling film on the jaw plates will do as a release agent. Its not quite that simple as some extra clamping will be needed to ensure the moving jaw doesn’t lift.

If they are both out a 1-2-3 block in the middle should work to do them both simultaneously.

There is a certain art to clamping when doing this sort of filler-in-place alignment as the moving reference parts need to be held tight enough not to lift yet be loose enough to slide. Stiffly.

Shimming is effective but can be a certain trial on patience. I never seem to have the right thickness in metal shims. The colour coded plastic shim sets are pretty good but they do have a mild tendency to squidge under serious loads. Which may be helpful for fine tuning.

The major issue with these inexpensive vices tends to be moving jaw lift. For conventional screw drive vices there is no substitute for accurate, close tolerance, manufacture if the vice is to work reliably and accurately. Pull down “acculock” devices can help but fundamentally these are the cherry on the top to make a well made vice work even better. On inexpensive products they invariably require fettling to work well and there are limits as to how much they can compensate for the less accurate fitting inevitable on a vice made to hit a low price point. As ever you get what you pay for and ordinary folk like us have to accept that when making £1 do the work of £5, or even £10, something must give.

I’ve long considered that treating a inexpensive vice as a casting kit to be converted to Chick pull down forwards or Gerardi push from the top of the back moving jaw operation might be a decent way of getting a better vice than you can directly afford. Basically slap a piece of gauge plate on top of the original base and have at it. The Chick pull rack looks do-able, an external screw to pull via a cross piece is far simpler than the internal arrangement o the real thing ought to work well enough. The pin through a hole locator for the push screw block on a Geraldi style is easier to make than the proper spring loaded ball in dimples albeit slower to use.

Clive

[Dave HalfordParticipant @davehalford22513]

Since you have the jaws off I would check that the vice base is in tram first or it throws the square measurement off.

[JohnFParticipant @johnf59703]

Moonman, I may be wrong but it looks as though your vice is not a “normal ” construction in that the fixed jaw appears to be bolted down to the base with a key for alignment ? A photo of the top of the vice will show its construction better.

If that is so then the best way forward is to correct the fixed jaw piece assuming its out of square — I feel its unlikely to be the actual jaw, this is easy to check for parallelism with a micrometer once its removed.

On what I would term a normal vice the fixed jaw support is part of the casting and even some of the well known makes could be slightly out of truth [1960’s onwards] so we used to use ‘silver paper” [aluminium foil] usually from a cigarette packet because it very thin and can be folded to make the right thickness shim. Might be frowned upon but believe me it worked.

Also when clamping work in the vice use a round bar between the moving jaw and the work positioned approx half way up the workpiece, this helps negate the rise of the movable jaw pushing the work away from the bottom of the fixed jaw.

John

[BazyleParticipant @bazyle]

This may well be intentional so it grips at the top. Last thing you want is a wobble due to a top gap since mostly you will have thumped the work’s reference face down onto the base. As with using a 3 jaw chuck when the supposed ability to hold on centre is important you check and compensate so with a vice.

[Bazyle]

On Bazyle Said:

This may well be intentional so it grips at the top. Last thing you want is a wobble due to a top gap since mostly you will have thumped the work’s reference face down onto the base. As with using a 3 jaw chuck when the supposed ability to hold on centre is important you check and compensate so with a vice.

On JohnF Said:

Moonman, I may be wrong but it looks as though your vice is not a “normal ” construction in that the fixed jaw appears to be bolted down to the base with a key for alignment ? A photo of the top of the vice will show its construction better.

If that is so then the best way forward is to correct the fixed jaw piece assuming its out of square — I feel its unlikely to be the actual jaw, this is easy to check for parallelism with a micrometer once its removed.

On what I would term a normal vice the fixed jaw support is part of the casting and even some of the well known makes could be slightly out of truth [1960’s onwards] so we used to use ‘silver paper” [aluminium foil] usually from a cigarette packet because it very thin and can be folded to make the right thickness shim. Might be frowned upon but believe me it worked.

Also when clamping work in the vice use a round bar between the moving jaw and the work positioned approx half way up the workpiece, this helps negate the rise of the movable jaw pushing the work away from the bottom of the fixed jaw.

John

John, this vice is a copy of the well known, respected and expensive made in USA Kurt vises, where the fixed rear jaw is indeed bolted to the base.

Tony

[Tony Pratt 1Participant @tonypratt1]

I had a similar problem on my offering from Arc, mostly went away when I got the fixed jaw ground parallel.

Tony

[moonmanParticipant @moonman]

Well tonight I fiddled around with it for an hour or so. The base is bang on tram in the Y direction.

While rough, the fixed jaw body is also pretty good and not a million miles out.

The jaw face itself is parallel and I cannot pick an error out with a mic.

The moving jaw is also square.

I did find a bunch of oil and even tiny bits of swarf behind the jaw face itself though so I gave everything a blood good cleaning and deburred the rough face with a stone. This has improved things somewhat but it’s not 100% perfect.

I ran a bit of scrap aluminium through the mill too to see if things improved, after facing 4 sides I’m still not cutting 100% square. This might be the excuse I need to pick up a surface table and get to the bottom of this or am I just better off finding a better vice…

I’ve got more time to play tomorrow where I intend on getting to the bottom of this.

[Kiwi BlokeParticipant @kiwibloke62605]

I may have missed it, but there’s no mention so far that the spindle of the mill has been determined to be accurately aligned to the reference surface of the vice. Forwards ‘nodding’ or backwards ‘leaning’ spindles are common…

Also, just what should be chosen as the ‘reference surface’ of the vice? It’s the base, if the workpiece is seated firmly, as it should be. As has been suggested, the slight inwards lean of the fixed jaw will grip the workpiece OK (provided that the moving jaw doesn’t do naughty things – hence use a roller), and any lean may be abolished when the vice is tightened (everything’s ‘made of rubber’). Obviously far better than an outwards lean.

If the face of the fixed jaw is taken to be the ‘reference face’, then it had better be spot-on with the vice relaxed, for setting up, and remain spot-on when the vice is tightened, which is going to be expensive – and unlikely, although with a massive vice, the error should be acceptably small. Better to trust the base as a reference.

[Clive FosterParticipant @clivefoster55965]

As Kiwi Bloke says the moving jaw is generally the issue when you have holding problems. Especially so with an inexpensive vice where making something the customer can afford seriously limits the production line attention that can be given to component fits.

Accurate holding from an affordable device has been a perennial machinist problem since about 5 minutes after the first machine vice was made! As mentioned above interposing a roller on one side of the job so the sketchy area contact from an inadequately aligned jaw is replaced by well defined line contact is a simple, effective and time honoured work around.

But it doesn’t suit all jobs and the extra loose part is a pain to hold.

Making your own jaw plate with a groove to hold the roller in place is an effective, relatively simple, way to make life easier. Clearly not a permanent fix but at least you can get on with making things whilst sorting out the ultimate solution. A dab of grease to hold the roller ould be good.

Maybe a block of soft alloy with two opposite sides parallel coated with blue could be used to investigate exactly whats going on has the vice is tightened. Basically inspect after suitable fractional turns of the handle as teh vice is tightened to see where the contact areas are. Needs to be something rigid but touch squidgy. A dial gauge on to to indicate any lift would be useful.

Given the angle of your fixed jaw you already have contact at the top of the work helping to hold it down. Generally any slackness in the moving jaw pushes the contact point down towards the bottom of the jaw. Hence the familiar tendency to lift the work and need to beat the job down onto the vice base or parallels.

Back in the day many vices, mostly production orientated types, were made with a vertical slope of the back fact of the jaw plate generating downwards force when tightened to pull the job down. Obviously the jaw plate wouldn’t have been dead tight because so sort of stiff sliding movement would be needed. Gerardi and other makes of expensive, professional market, machine vices still use this system so it’s likely to be of some value.

I wonder whether something similar could be devices as a bolt on retrofit for inexpensive vices suffering from moving jaw lift. Two jaw plates with opposing tapers would be needed. One firmly affixed to the vice moving jaw mount and one just a tad looser so it can slide. Presumably some sort of lift spring would also be needed so the actual gripping jaw had somewhere to slide.

Clive

[JasonBModerator @jasonb]

These particular vices have an angled arrangement anyway to help keep the moving jaw down, some people like to smooth the spherical joint a bit more but the one I regularly use seems OK.

[Tony Pratt 1]

On Tony Pratt 1 Said:

John, this vice is a copy of the well known, respected and expensive made in USA Kurt vises, where the fixed rear jaw is indeed bolted to the base.

Tony

Thanks Tony, I have seen Kurt vices in use in forum photo’s and they clearly have a good reputation in the US but never actually seen one one in the flesh so had no idea of their construction details !

John

[JasonBModerator @jasonb]

Though it does seem they have gone away from the bolt of fixed jaw for most sizes of vice, only having the 10″ version with the separate jaw. latest ones are all part of the casting.

[moonmanParticipant @moonman]

My mill does have about 2 thou of nod for which there is no adjustment and as it’s one of the mills designed to bolt onto a lathe (it’s a Chester Champion 16) it’s going to be difficult to shim.

Using the base as a reference makes sense, with the videos I’ve seen online about squaring stock it’s always the fixed jaw people talk about being the reference but I always make sure my parallels are tight so I guess I am actually referencing the base when I think about it.

I shall recheck the tram of the mill tonight, although I did do this last month when cleaning everything.

[moonman]

On moonman Said:

My mill does have about 2 thou of nod for which there is no adjustment and as it’s one of the mills designed to bolt onto a lathe (it’s a Chester Champion 16) it’s going to be difficult to shim.

 

Using the base as a reference makes sense, with the videos I’ve seen online about squaring stock it’s always the fixed jaw people talk about being the reference but I always make sure my parallels are tight so I guess I am actually referencing the base when I think about it.

When squaring stock it IS the rear fixed jaw you need as the ref face. Any face resting on the vice base or parallels will be parallel to the surface being machined. You want to be machining at 90deg to a previously machined surface hence the rear jaw as that is (or should be ) at right angles to the surface being machined.

If there is a bracket that screws to the back of the lathe bed then packing that will help with nod.

[Howard LewisParticipant @howardlewis46836]

If the face of the base is flat and free from bruises (Clean up with a stone if not) that should be the reference face.

Of any machined face of the casting is out, it can be very lightly skimmed to to bring it back square to the base.

Then it needs to be checked that each jaw, especially the fixed one, is parallel to the mounting faces, and parallel to the machine bed.

So lots of clocking, cleaning and possibly light machining, and some stoning.

How much depends on: How precise you want to be, and how rigid is the vice as whole.

If the vice and it’ set up are not rigid, it will flex under cutting loads, and you never will get accurate results. You will then have to reduce the cuts and feed rates to reduce flexing.

A hobby machine is not going to be as heavy, rigid, or as powerful, as an industrial machine, so needs to be treated more gently, with respect to the characteristics of the machine.

Howard

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