Metric Dial gauges

[C_lazy_F_Guns]

Why do people have to get pedantic with measurements , I did say it was around 0.0003 the 0.000094 doesnt really matter in most daily used equipment and if it did then I would purchase an electron microscope and a set of similarly scaled scraping tools to remove a few atoms which may be forming a ridge on the surface.
Perfection is not something to strive for in many areas , if a part fits and works as well as lasting, that is what really matters , sometimes that last few tenth's or hundreths of a thou can push the repair time into an area where customers can and have refused to pay for excessive time spent .

If a part will allow a machine however large or small to be put back into service where it earns dollars for the owner and it lasts longer than the original , then that is what I look to acheive .

I do most of my work for money and have built a reputation for quick and lasting repairs over quite a few years .
I can work to the fine tolerances that many here take pride in acheiving but if that is not required then why spend 4 - 6 hours on a part with the constant risk of scrapping a weeks work in total just for someone elses gratification..
Michael

I largely agree with you but I have also found it to be a wise and time saving habit to round the numbers rather than just drop them. In this case, working so far right of the decimal it matters little but is a habit that can bight you. We stick these easy numbers in our head then someday down the road we go lets see that was 3 so 9x3 is 27 . . .but 9x4=36 and the actual correction is number is .0035. Now your over .008 out instead of just .0015 out and it would have been just as easy to stick .004 in your head as .003.



Rounding those tiny numbers is a good habit to have. Not rounding is a bad habit about like running a drill bit up-n-down in the finished hole like it’s a reamer thinking it knocks the blowout off the back, won’t harm a thing . . . till it does and sends a $3000 missile housing to the scrap bin. Yup, that’s when I fixed that bad drilling habit!

[mike4]

I did find the thread for the bar , 5mm 0.8 pitch will screw in easily by fingers there was some hard grease in the threads.
As for the bite when Peter "corrected me , I am not one to get interested in the 0.000395 its close to 0.0003 or it could be 0.0004 , depending on what is being measured .
I did say that I was checking the run out on a shaft .The shaft in question is allowed +/- 0.01mm when working.

All I want to do is set up an instrument and monitor the shaft in operation as there appears to be a bearing with some vibration and the shaft has been out and checked for straight and its still within manufacturers specs of 0.01 mm no +or - spot on , no wear on the bearing surfaces .

But with 4 hours required to remove one bearing and about 2 for the other end , I am just trying to see what the problem is .
Thanks for the replies .
Michael

[mike4]

One more thing ,I did say around , not exactly 0.0003 .

If others want to speak in exact measurements thats ok , I only worry about how much should be added or subtracted when I am drawing or machining , measuring parts not when talking about something.

Thats how I am and I'm sorry if I bit when "corrected by Peter" , I was more interested in the thread on the end of the bar so that I could finish trouble shooting this transmission.

Michael

[mike4]

The indicator has allowed me to find which bearing was running a little roughly , it has been removed and replaced .
I cleaned the bearing expecting to find the surface of the race or balls to be damaged as there was a noticeable tight or rough feeling when the bearing was rotated .

It turned out to be a manufacturers fault , during assembly there was a pin left longer that the rest (the ones that hold the cage together) and it was catching occasionally . So much for quality control or was it planned failure?

the transmission was three days old and neither myself or the owner are even remotely bothered with warranty as the makers service engineer couldnt find what was causing the vibration.

Michael

[jep24601]

Sorry to correct you but it's actually almost 0.0004" (0.000394")

Yes, 0.01mm is around 0.0004". It is not close to being around 0.0003" by about (around?) 25% to 33%

[mike4]

It is obvious that many prefer to be totally correct at all times , I would like to know how many of the people are or have worked in the field where often parts are machine to "fit and work" where we have to make a part fit either by removing a small amount of material or build up and machine to size .
All of the time having to work with equipment that is often assembled from parts which are sourced from the cheapest supplier by the OEM's .

I have often had to remove 0.01 mm and thats with portable equipment , hired for the job when the precision part wont fit because it was made to the specified tolerances , but should have been slightly smaller or larger in diameter using a shaft as an example .

I do not have to justify the methods used because they work and customers are happy.

I dont often have to worry about the 0.0000937 of an inch with most of the gear that I work with and the indicator only had to show how much the shaft was moving at each end so that I could determine which bearing was causing the vibration .

I was measuring a total movement of 1 division which was 0.01 mm this was enough to cause what felt like a bent shaft to the operator .

If I have to there are instruments available to allow detection of the amount in question but as its not always necessary to go to those tolerances I have only had to hire it twice in ten years.

Michael

[EddyCurr]

I recently purchased a Mituyo 1160 ... the grubscrew is missing ...
... 5mm 0.8 pitch will screw in easily ...

Were you successful in finding a replacement ?

FWIW - I had success when I approached Mitutoyo Canada seeking a replacement part
for one of their instruments. There may be a representative more local, but this one
apparently services Aus

M.T.I Qualos Pty. Ltd.
55 Northern Road,
West Heidelberg,
Vic. 3081
(61)3-9450 1900 Ph
(61)3-9458 3217 Fax
[email protected]
http://www.mitutoyo.com.au

The above is from Mitutoyo's Asia/Pacific page

.

[RichR]

Hi Michael

It is obvious that many prefer to be totally correct at all times

I think the objection is that you made the approximation by truncating rather than rounding. I use approximations every time an
inch based wrench won't fit because a bolt happens to have a metric head (or vice versa). I use 0.04"=1mm because I can do the
math in my head and the answer will be close enough to pick the right wrench.

[mike4]

EddyCurr ,
Thanks for that link,.
RichR , thats the way that I think 19mm approx 3/4 some bolt sizes are almost equal as are some threads for a lot of practical purposes , high tolerance or high stress then go for exact replacements.
Michael

[Yow Ling]

In my world 0.01mm is more or less exactly half a thou.

[C_lazy_F_Guns]

I have often had to remove 0.01 mm and thats with portable equipment , hired for the job when the precision part wont fit because it was made to the specified tolerances , but should have been slightly smaller or larger in diameter using a shaft as an example.

Do it every day, call it fitting-up . . . It’s usually made easer measure accurately and rounding to the needed tolerance be it 10mm, 1mm, 0.1mm, 0.01mm, or 0.001mm.

I do not have to justify the methods used because they work and customers are happy.

No, you don’t and I for one don’t care what you do or how you do it. But you could maybe wise conceder maybe, just could be by some small chance some valid reason your way through up red flags to so many. Do you have the Mother watching her kid march in the band story down-under? “Look at that, my kid id the only one marching in step!”


Could be we busy body perfectionists types were only trying to help you not repeat our costley mistakes?


Anyway, I never meant to fray any of your nerves and I’m sorry for saying anything about it.

[Alistair Hosie]

You can always re tap it with an imperial thread although even in imperial USA it should be easy enough to get one. Alistair

[mike4]

I am not going to post the measurements of any instrument again as every time the post is mis- interpreted , I only really wanted to know what thread and the diameter of the rod for the gauge .

I will not alter any instrument which I have just purchased but thanks for the suggestion.

Michael

[Peter.]

It's a discussion forum Mike. People will offer what they think might be a valid point even if it isn't what you might want them to say. If the only reply you expected was a simple "m5 x 0.8mm" then an email to Mitutoyo would have got you that and you could have saved all the extraneous interaction. Of course, you'd miss out on the rich diversity of ideas and information that comes along with the forum but that's your call - some people enjoy it, others less so.

[mike4]

Peter,
I work as required and often do not have the luxury or waiting for a person employed at a business to return from holidays to provide information which the manufacturer do not list on their website .

My business is 24/7 365 on call by my choosing not anyone elses .

I dont work to conventional ideas , if i need to I will work for 24 hours straight to get the job completed then have a sleep , but if required I will turn up at work on the next afternoon .

I wont get involved with the niceties of discussing the finer points of measurements any more as it isnt worth the time.

As I said in the first post all I wanted was the rod and thread size , I I knew and someone asked me I would tell them without the other discussion which arose.

I like to keep it simple , I am actually put off by anyone who goes around with an attitude of it being necessary to go into the finer points of measurement instead of just getting on with the task at hand .

I can and do use precision daily but its just part of the job , job over all measurements written on jobsheet and customer charged , finished move onto next task .

I dont mind if others wish to discuss the matter but not ever on my time , that is why I have not employed any permanent staff for five years apart from the high costs , people tend to treat employment as a problem with their social life .

Michael