when is a precision vice not a precision vice>?

...and I didn't read it as such; it was a helpful, well thought-out and well expressed post IMHO. But as you will no doubt have discovered, you can't win in this forum - whatever your intentions, someone will choose to mis-interpret them.

Regards,

Tony

Tony

I couldn't agree more that people will take their own interpretation on any post and that's why everyone has the right to reply but Pete's opinions are obviously similar to yours so you agree with what he is saying.

Pete is equally as guilty of taking his own take on postings as he has gone off on a tangent about RR quality and saying he did not mention this, no he didn't but he was implying this level of standard and all I was pointing out was not everyone needs that level or can afford that level. I could not not agree more quality costs, but rather than go on an on about the cost of quality accept that just because something is expensive its not the best. And equally there will be a product that cost less than he paid that will do the job.

A perfect example of this is the thread about Aldi callipers where one person is disappointed with his callipers even though he states they are accurate and do exactly what was stated on the box and he paid £8.99 shocking they should have been 99p

I have these and I also have Mitutyo both give the same reading but no way am I suggesting they are as good as the Mitutoyo but there are plenty of people who are using the Aldi callipers and have done for many years, however there are people who would not allow them in their workshop.

I am not being personal when I disagree with an opinion just putting my point over I accept I may also use the wrong choice of words and someone may misinterpreted my meaning and equally I may misinterpret others but I will try and correct this as necessary.

I think this thread is going around in circles because there is nothing new just a discussion about quality and not vices so in no way is this helping any so called newbie choose a vice.

Well said Brian

just had an interesting conversation with the wife:-

Me- I need a machine vice to go with that new mill I have just aquired.

Wife-Thats nice dear, how much will it cost?

Me - £500 my sweet!

Wife - might I suggest you buy two , you will have one for spares then.

Me - What a spiffing suggestion my love,

At this point I woke up as I was being browbeaten by said good wife for spending our hard earned money on more rubbish for that bl****y shed!

This forum is no different to all the others I subscribe to (covering my other interests), where the thought process is- you can achieve anything just by throwing money at it.

where as in reality, time spent acquiring the necessary skills gives a far better return.

it is just that, throwing money at something (for some) is a much easier proposition.

At the rtisk of adding fuel to the fire .

precision vice.

vice === device for SECURELY holding work "down" for machining.

I doubt any will materuialy disagree with that.

Precision on the other hand is more slippery

If you have vice A which is repeatable and "nice" to use a job can be set rapidily with little fuss.

Vice B is a pig and needs coaxing to hold squarely and repeatiedly ..

two situations arise. for making P parts

1 cost A N* X pounds cost B X pounds

2 setting time A Y minutes setting time B M*Y minutes

payback time A = N*X/(Y*P)

payback time B = X/(M*Y*P)

thus pb A /pb B = M*N ...which after all that seems obvious..

ie if vice A cost 10 times as much It must be setterable in tenth of the time...

that is of course if payback time means anything.. my hobby time is limited so I wish to reduce setting time but my budget is also limited.. and who can estimate M from a catalogue anyway!...

Seriously ....

Brand does not ensure quality any more..( its worse since quality itself appears to be inconsistent..... " reserve the right to alter specifications at anytime"...)

The OP was able to fettle his vice .. and has something fit for his needs ( and who else can say what they are) ..we have all had experience of "buyers remorse" and will unfortunatly will continue to do so.

... I plan this to my last on this ..

Jason

Hi Jason

You have forgotten to add in the lifetime value of the vice.

Would the cheap vice need renewing every say 5 years while the precision vice lasts a lifetime.

regards David

Ah well, looks like the money I spent on a Kurt D688 was wasted then. Never mind, if I didn't throw the money at the workshop I'd only blow it on wine, women and song, well, may be not so much of the song.

Andrew

I confess I am somewhat confused by the difference between a quality vice, which is what we seem to be considering here and a precision vice. Precision vices seem to be ground all over and presumably their dimensions and squareness are controlled to some sort of tolerance. This suggests to me that that are used for something more than holding a bar whilst tidying up the saw cut with an endmill, perhaps as an aid to toolsetting. Can any toolroom expert comment?

cheers,

Rod

exactly my point, if works but wears out after five years of production use or even 1 year but its going to be used infrequently its good enough for some but not for others. I keep saying fit for purpose

""Hi Jason

You have forgotten to add in the lifetime value of the vice.

Would the cheap vice need renewing every say 5 years while the precision vice lasts a lifetime.

regards David""

Seems only polite to answer..

True cost in place costs and residual values are neglected in the above..

and Roderick Jenkins rasises a valid point what makes a vice presion as apposed to "good".

To this and many other things I have no answer

A precision vice is one that can be trusted and is a joy to use as opposed to one that constantly needs to be checked and is a chore to use. You get this argument on numerous camera forums, usually something like Leica versus Zenith. Yes, both are capable of taking photos but one helps the photographer while the other makes it hard work.

Jason,

There is an excellent page on Wikipedia, discussing Accuracy and Precision.

I hinted, in an earlier post, that there was a distinction; but did not press the point.

... Chris is absolutely right that Precision brings Trust and "Joy to Use"

Horologists reognise the distinction, when they refer to the Rate of a Chronometer. ... Ships' Chronometers are often "inaccurate" insofar as they run fast or slow; but the Rate is known, and reliably constant.

In the Engineering context, I think it fair to say that Precision = Repeatability

Fizzie's Vice had low precision, because it was loose.

MichaelG.

There's a useful discussion of accuracy and precision here:

http://en.wikipedia.org/wiki/Accuracy_and_precision

Which demonstrates that "precision" (a measure) is often and incorrectly substituted for "precise" (an absolute and non-achievable goal).

All vices are precision vices; however, any particular vice may or may not have the precision that you are looking for. So a useful definition of a "good" vice would be one whose precision meets or exceeds the needs of the task that you have in mind for it.

Regards,

Tony

True story.
As lads we used to meet outside the local chip shop of a night and try to impress our mates and Gladys Turnbuckle who was the local bike.

So one night we were all bragging about have good we had to be at our jobs. Can't remember what I said but it wasn't impressive, Gladys wasn't there at the time.

Then this smarmy bastard from Rolls Royce gave us all a lecture on what tolerances they had to work to. Good job Gladys wasn't there, he'd have stood no chance !

Then it was the turn of Albert who worked in the foundry at the local wagon works making bits for goods carriages who very, very seriously told us that they didn't have to work to tolerances, everything according to his foreman had to be knob on.

From that day on Albert was known as Knob On and next time Gladys came round the chip shop she thought she'd missed something and latched on to Knob On.

Buying good quality is always money spent well, throwing money at wine women and song is never miss spent either.......

"When is a precision vice not a precision vice?"

When it fails to meet your personal expectations of what a precision vice should be.

.

Which, I suppose, only leaves one person able to answer the original question

Fizzy ... who has been conspicuous by his absence, for these eight pages.

Where are you, Fizzy? ... Presumably busy in the Workshop !!

MichaelG.

Really pleased you posted that pic Neil. I fixed one of these for a friend last week and there was no indication of its origin. One of those "unanswered questions" now answered!

Thanks for that, and for the record they are quite a substantial thing.

graham.

It amazes me how you blokes can, and want to, go on and on disagreeing, aligning with others; introducing, inevitably these days, so-called 'rights', drawing attention to friend's and enemy's work, circling, circling on and on.

It may be that I am envious of the amount of time that you have available for such combats

Something to do with the average modern diet perhaps.

Mining the archive of our forum's posts [for reasons we need not discuss], I came across this thread ... which started in 2013 and then 'hibernated' in 2014.

I say 'hibernated' because Fizzy's original question was never satisfactorily answered.

This morning I found a range of 'precision' Vices [Vises] which might reasonably be considered 'definitive'

... there is also a remarkable Right Angle Plate !

**LINK**

https://www.cutwel.co.uk/FileDepository/banners/new%20banners%20aug/milling/Insize%20Sine%20Bars,%20Vices%20and%20Plates.pdf

As we have several recent members, who will hopefully have an opinion; I suggest this thread merits a revival.

MichaelG.

.

Note: in my opinion, the prices are irrelevant to the original question, but obviously they are substantial:

https://www.cutwel.co.uk/workholding/edm-toolmaking-grinding-and-inspection-workholding/sine-vices-bars-and-tables

Edited By Michael Gilligan on 17/08/2018 08:15:55

Missed this post first time around, but my response would have been..........

Q: When is a precision vice not a precision vice ?

A: Mainly when i use it