what is this for

Advert

New Replies

Report Bug

Help/FAQs

what is this for

This topic has 8 replies, 6 voices, and was last updated 27 January 2019 at 19:37 by Michael Gilligan.

Viewing 9 posts - 1 through 9 (of 9 total)

Author

Posts
27 January 2019 at 14:18 #19224
simon Hewitt 1
Participant
@simonhewitt1
what are the sticky up bits?
Advert

27 January 2019 at 14:20 #393228
simon Hewitt 1
Participant
@simonhewitt1
attempt 2:

This is a precision micrometer I bought recently, it is a fine tool and seems accurate to about 1/10 th thou. But what are the pillars on the top for? Anyone got any ideas?

Thanks

SImon
27 January 2019 at 15:05 #393233
Jeff Dayman
Participant
@jeffdayman43397
The pillars are probably for suspending the item to be measured between the micrometer anvils, to keep heat from the fingers away from it. When working in the tenths of a thou world, temp control is important for accuracy. See wikipedia for "thermal expansion of metals". Delta T is key, as one old measuring technician in the toolroom where I started work used to say, often……
27 January 2019 at 17:42 #393253
Robert Atkinson 2
Participant
@robertatkinson2
Is the item on the left spring loaded? If it is and the index mark moves it could ne for measuring thickness of a elastomeric material under a pre-defined load.

Robert G8RPI.
27 January 2019 at 17:46 #393254
Samsaranda
Participant
@samsaranda
Lightning conductors !

Dave W
27 January 2019 at 18:08 #393257
Michael Gilligan
Participant
@michaelgilligan61133
Posted by Robert Atkinson 2 on 27/01/2019 17:42:57:

Is the item on the left spring loaded?

.

That makes it a 'fiducial micrometer'

Bedtime reading here, courtesy of NPL : **LINK**

http://resource.npl.co.uk/docs/science_technology/dimensional/moy-scmi/moy-scmi-22-print.pdf

MichaelG.
27 January 2019 at 18:47 #393263
Involute Curve
Participant
@involutecurve
I have a floating carriage Micrometer with a fiducial setup very similar to the one above, I inherited it from my granddad, I've never used it, Ill dig it out of its storage box and take some pics if anyone interested.

Shaun
27 January 2019 at 19:30 #393267
simon Hewitt 1
Participant
@simonhewitt1
The black barrel on the left is spring-loaded, with a simple moving pointer that lines up with a fixed pointer to provide a repeatable force. I don't think the movement is necessarily enough to accommodate particularly elastic material. On the end of this barrel, it does say 'made to NPL design', so yes it is as per the specification from Robert above.

I don't think the posts are to suspend the work as they are not central, both are 'behind' the barrel for right-hand use. Lightning conductors seems more likely, I will try outside with a calibration piece next time we have a thunderstorm.
27 January 2019 at 19:37 #393268
Michael Gilligan
Participant
@michaelgilligan61133
Posted by simon Hewitt 1 on 27/01/2019 19:30:23:

On the end of this barrel, it does say 'made to NPL design', so yes it is as per the specification from Robert above.

.

… Thanks

MichaelG.
Author

Posts