Member postings for Pete

Hi Martin,

Thanks for the encouragement to post more often. Norman will know me and my thoughts, John Stevenson will also know me from the HSM forum.LOL,Then again they may not freely admit to that fact. There's a few others I can place due to their user names.

There is, And thankfully it is very uncomman, The very rare person who gets a weird perverse satisfaction from knowingly posting incorrect information. I'm not the type who tollerates games like that at the expence of the inexperienced. So far I've yet to see one of those on this forum. So I guess I should post or at least spend more time here. Overall there is much less argueing, And it seems much more actual logic used on this forum, So that's a nice refreshing change.

Well except for that last picture of Sir Johns that is. I do have to laugh every time I see it.

Pete

Edited By Pete on 09/06/2012 23:57:05

Yes,I do know what the artical says, But it also doesn't say what accuracys you can resonablly expect. And as I mentioned, Far too many think because there's all those zeros after the decimal point, Then anything digital has to be really accurate no matter how cheap it is to buy. And nowhere does it mention or warn against destroying any value that's left on all those finely built Vernier Gages. There's a lot of those older height gages around now at fairly cheap prices, And yes a cheap one was used in that artical. Personaly I'd hate to see that type of work done on some of these old but fine tools due to inexperience and thinking it's a great idea to do so. If you do know your going to destroy a tools value and still chose to do so? That's fine, But a bit illogical to me.

And I'd also agree that very accurate digital equipment can be bought today that is extremly accurate. But not normaly at a price most of us would be happy to pay. I know exactly how much it hurt to buy my 12" digital Mitutoyo, And it's repeatable accuracy. But I also have a very good set of gage blocks that do allow accurate checks to be done. So if and when it's rarely required, I can use my height gage for accurate measurements beyond the inaccuracys of the tool itself.

Industry has gone to digital equipment for many reasons, Less mistakes, speed of measurements, ease of usage would be just 3.That's also why I've bought some digital equipment. LOL, Due to age and not needing that magnifying glass is really nice too.

I guess the main reason I started this thread was it cost me far too much to lean the little I do know the hard way. I wouldn't like to see anyone else have to do the same. Maybe I'm wrong, But I still happen to think forums like these are or should be where the more experienced can help to educate the less experienced. And since this sub forum is for anything in MEW. I figured this was the correct place to add what I thought was missed in that artical. Overall I do think it was well done. It's just that it missed those important points.

And as usual, John Stevenson is 100% correct, But that's another reason I bought good gage blocks. I can calibrate and check my own equipment so they all agree with each other. Maybe not to National recognised standards. But my gage blocks are my standards. Yearly metrology lab recertification probably isn't needed by the vast majority here either. Being within a few thou is more than good enough for almost anything most including myself will normaly need to do.

But If this thread helps even one person to understand the value of some of the older tooling and the difference between resolution and accuracy, Then it will have been worth it IMO.

Pete

I had to think really hard before posting about this since many will disagree with me. But the artical in the July issue of MEW does require some additional information that wasn't properly covered.

It's not my place to say what anyone should or shouldn't do with anything they happen to own or buy. But due to inexperience, People following that artical may end up with far less than they started with. Starret and Mitutoyo to name just 2 manufactures today still produce high quality vernier height gages. And there were litterly dozens more in the past. All those very well made vernier height gages are in fact a lot more accurate (but slower to read) than most high cost and barely affordable dial and digital models built today. There's not enough information around, But it really should be closer to comman knowlege. You should search for what the terms actually mean when buying accurate metrology equipment. Accuracy and resolution are not properly understood and confused by far too many.

If you were to spend less than an hour learning the proper way to read a vernier scale, And a bit of time checking the accuracys obtainable with them against what the much higher priced dial and digital ones are capable of? Then personaly I don't think I'd be all that quick to convert a well made but older vernier gage over to digital. And I'm saying that because I bought a brand new digital height gage built by Mitutoyo. Both Mitutoyo and Starrett built very high quality equipment with the prices to match. So if they build far in excess of $1,000.00 height gages with all the technology they have avalible, Yet they state the repeatable accuracys are only within a couple of .001?

Personaly I fail to see where adapting a rather cheaply made Chinese digital scale will give you anything approaching what the original vernier scale does for repeatable accuracy on a tool that was well made and accurate to begin with. Yes it's faster, But a tape measure is also much faster and much cheaper than a height gage.

If the accuracys avalible from those cheaper built digital height gages are good enough for what your doing? Then I'd just buy one of those and refrain from making irreversable modifications to an old tool that will be mostly worthless to anyone else once your done with it.

Pete

Neil has answered your question very well. As an extra on exactly why you shouldn't over tighten that drawbar. Hard hammering on the end of the drawbar will drasicly shorten the life of your spindle bearings. There's not a ball or roller type bearing made that will tolerate high shock loads to them without shortening that life span.

Pete