Mis-read micrometer by .025"

[rklopp]

I've done it more than once! Saturday I decided to remake the leaky contra-piston of my ML Midge "Diesel." I measured the old one and came up with 0.4201". I made the new one dead nuts. Only problem is, the bore is 0.3951"! I misread the micrometer as 0.4000+0.0201 instead of 0.3750+0.0201. I remember looking at the drawing after I measured the old one and thinking, "Wow, I really over-bored this thing." I should have listened to my gut. Still, no digital mikes for me!

 

[kcmillin]

This is can be a common problem, I have most trouble with reverse reading micrometers like inside mic's groove mic's, and depth mic's.

At least you made it too big I usually go the other way :big:

Kel

 

[Metal Butcher]

I've done it more than once! Saturday I decided to remake the leaky contra-piston of my ML Midge "Diesel." I measured the old one and came up with 0.4201". I made the new one dead nuts. Only problem is, the bore is 0.3951"! I misread the micrometer as 0.4000+0.0201 instead of 0.3750+0.0201. I remember looking at the drawing after I measured the old one and thinking, "Wow, I really over-bored this thing." I should have listened to my gut. Still, no digital mikes for me!

That's a small mistake, don't let it bother you for more than a minute.

A few years back I needed to make a simple link. A thin strip of brass with drilled holes on both ends. I cut seven (7) pieces individually one after another and each one was the wrong length!

I was at the very end of my whits when I discovered my digital caliper got zeroed out with the jaws slightly open. oh:

So much for the 'digital solution'.

-MB

 

[Chaffe]

The worst feeling in the world has to be the spilt second before the machine hits the material in rapid and you know you can do nothing about it, because you have put a decimal point in the wrong place when adjusting an offset! CNC programming at its best

 

[rake60]

That's an age old trick rklopp.

Over the past 30 years, more than once, I cut bearing fits exactly .025" under size.
I'm talking about bearing fits over 25" in diameter.
Nailed that .0005" tolerance every time, just .025" too short.

Back to the welding shop for a little more work with the "put-on" tool. :-\

Rick

 

[Tin Falcon]

when I worked running the cnc lathe for a living I would always double check my measurement with my digital calipers. I do not expect calipers to be accurate to more than a couple of thou much less a couple tenths but they will pick a .025 error.
I just picked up a couple of these http://www.fvfowler.com/ez-read.html actually a 0-4 set less the 0-1. not terribly expensive and not messing with verniers or replacing batteries.
Tin

 

[steamer]

YUP Been there and done that...probably do it again too!

The Use the caliper trick until your close works for me too.

Dave

 

[lazylathe]

A good friend of mine gave me a Browne and Sharpe mike a while back.
Still learning how to read the stupid thing! :-\

I have never worked in inches, fractions and decimals of inches!
It is all Greek to me.... ???

My vernier can be switched between the two but as you all say it is good for a guesstimate only.
I need to either get an EZ read mike like Tins or just get one in mm's.
Both would be good so as not to have to convert everything and hope i do it right...

Andrew

 

[miker]

I screwed up by misreading more than once. Old eyes!!
Bought this and have been happy.

http://www.ctctools.biz/servlet/the-90/0-dsh-1"-(0-dsh-25MM)-DIGITAL-HIGH/Detail

 

[chillybilly]

At last "I AM NOT ALONE " :big:

Dont trust the digi stuff much ,can go a bit La la when they get cold and wreck the job that way .

Best plan is try not to do it on the expensive /complicated/massive time invested stuff!!!!!!!!!!!

 

[DaveH]

You're never alone with a Stand

Dave

 

[Tin Falcon]

I have a set of digital electronics as well. I have found the digitals to be very reliable unless the battery dies then you replace it and move on. Just keep a handful of batteries on hand for multiple electronic units I have iirc at lease a half dozen units between the several calipers a couple of digital indicators and the mics
Tin

 

[kennyb]

My grandfather was a quartermaster machinist at the Brooklyn navy yard for most of his life. He passed away about 50 years ago when I was 10. All of his belongings were dispersed throughout the family. For some reason my mother got his machinist chest. I got it about 10 years later. Everything is starrett, and I mean a lot of measuring equipment, taps and dies. I've used them for all these years and the only digital readout I have is a 6" caliper that someone gave me. I love my vintage tools.
Ken

 

[rake60]

YUP Been there and done that...probably do it again too!

The Use the caliper trick until your close works for me too.

Dave

I agree 100%

I don't trust digital measuring devises. That's my age showing...

I also use the dial calipers to get it close. These 6" Mitutoyo calipers to be exact.

Orange face, .100" is a full revolution on the dial so I can actually read it without my
bug eye glasses.

That photo was from the day I bought them. Seriously! I buy NEW tools once in awhile.

Rick