Author Topic: Using digital callipers  (Read 5610 times)

Offline Will_D

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Using digital callipers
« on: October 29, 2014, 04:33:14 PM »
I am sure someone else has suggested this but here goes:

Lathe Work 101:
Turning a shaft down to size:

Old Way:
Measure the stock, take a cleaning cut (to round the stock) then measure again.
On a piece of paper: Subtract desired from actual and divide by 2 (depends on your dials!). This is then the amount to remove.
Take more cuts and repeat the above until finished!

New Way:
As most of us use digital callipers:

Round the work as above.
Manually set the callipers to finished size and then zero them.
Apply callipers to work, measure, and divide the reading by 2 no need for paper!

Ok so this is for getting very close, a precision mike is still the way to go
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Offline Manxmodder

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Re: Using digital callipers
« Reply #1 on: October 29, 2014, 08:52:31 PM »
Will D,I have used that method for many years. It's one of the real advantages of digital scales.

Same technique applies for digital micrometers......OZ.
Helixes aren't always downward spirals,sometimes they're screwed up

Offline AdeV

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Re: Using digital callipers
« Reply #2 on: October 30, 2014, 06:04:47 AM »
I still use the first method, but that's because I'm usually working in millimetres, and my lathe works in inches...
Cheers!
Ade.
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Offline awemawson

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Re: Using digital callipers
« Reply #3 on: October 30, 2014, 06:41:33 AM »
Getting a DRO on my lathe was 'The Best Thing'. I take a clean up cut to concentricity. Then I take a cut of the doc I expect to use and measure the part. Set the DRO to that value and cut until I have two or three passes left. Once more I measure the part, make any correction necessary to the DRO, and cut to finished size. This way you can take a decent cut as the final cut, which I find advantageous using indexable carbide inserts.

No reason that a digital vernier cannot be used in exactly the same way as my DRO. I have to say I never look at the dials on the lathe, only the DRO !
Andrew Mawson
East Sussex

Offline Will_D

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Re: Using digital callipers
« Reply #4 on: October 30, 2014, 06:58:34 AM »
I still use the first method, but that's because I'm usually working in millimetres, and my lathe works in inches...
So set to say 32 mm manually, zero it, press the ins/mm button, now when you read it the amount to remove will be in inches.
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lordedmond

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Re: Using digital callipers
« Reply #5 on: October 30, 2014, 08:46:40 AM »
I to use that method but it's easy for me as my lathe has dials for the dia.

So the guess o meters tell me I have 1mm to take off just dial in 1 on the dial and Bobs your uncle

Stuart

Offline AdeV

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Re: Using digital callipers
« Reply #6 on: October 30, 2014, 10:20:44 PM »
I still use the first method, but that's because I'm usually working in millimetres, and my lathe works in inches...
So set to say 32 mm manually, zero it, press the ins/mm button, now when you read it the amount to remove will be in inches.

OK, now I feel stupid  :smart:  :scratch:  :coffee:  :zap:

I shall definitely remember that trick for next time, thank you!
Cheers!
Ade.
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Offline dawesy

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Re: Using digital callipers
« Reply #7 on: October 31, 2014, 06:16:30 AM »
It's always the simple ways that we overlook :/
Lee.
wishing my workshop was larger :(

Offline John Stevenson

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Re: Using digital callipers
« Reply #8 on: October 31, 2014, 06:29:26 AM »
Finding the centre of two holes.

Holes need to be the same size.

Stick the internal points into one hole and measure across, then zero the calliper.
Now measure from the outside of one hole to the outside of the other with the infernal points and you have the centre distance.
John Stevenson

Offline Manxmodder

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Re: Using digital callipers
« Reply #9 on: November 02, 2014, 08:22:14 AM »
John,I like your method  :clap: .I must remember to give that a try next time I need to find relative centre distances....OZ
Helixes aren't always downward spirals,sometimes they're screwed up

Offline John Stevenson

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Re: Using digital callipers
« Reply #10 on: November 02, 2014, 10:09:23 AM »
Sorry should have typed centre distance of two holes, too late to edit post now.
John Stevenson

Offline Rubes

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Re: Using digital callipers
« Reply #11 on: November 02, 2014, 04:06:25 PM »
Finding the centre distance of two holes.

Holes need to be the same size.

Stick the internal points into one hole and measure across, then zero the calliper.
Now measure from the outside of one hole to the outside of the other with the infernal points and you have the centre distance.
Similar technique works on center distance of two posts, bolts, etc.
measure outside from post to post, zero...measure one of the posts...the reading will be negative, but ill be the center distance.

Hmmm...funny how the mind works, or doesn't in this case...but the technique is actually the exact same for two posts as it is for two holes...is just that I've always used the two different ways. oh well, as they say, a mind is a terrible thing...hehehe.
« Last Edit: November 02, 2014, 07:23:58 PM by Rubes »