ExHempKnight

ExHempKnight OP t1_j92qn5d wrote

Reply to comment by A_Light_Spark in "The longest-lived micrometer than can be bought." J.T. Slocomb micrometers and stand, all fully restored by myself. Each mic is between 70-120 years old, and they're all still accurate. by ExHempKnight

Mostly true. The threads, spindle and spindle bushing, and (most importantly) the measuring faces, are all subject to wear and corrosion. This brand in particular compensates for thread wear in a unique (and in my opinion, superior) way, compared to Starrett or Mitutoyo. The bushings are also replaceable, which I'm not sure is an option with the other brands.

And as old as these mics are, and as much work as I've put into them... They can almost certainly benefit from having the faces lapped. That's really the only thing keeping them from being good as (or better than) new. But I don't have the equipment to do that, and having it done is not cheap (especially for as large a set as I have).

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ExHempKnight OP t1_j92ovww wrote

Reply to comment by VisualKeiKei in "The longest-lived micrometer than can be bought." J.T. Slocomb micrometers and stand, all fully restored by myself. Each mic is between 70-120 years old, and they're all still accurate. by ExHempKnight

Lol I dunno about all that. These mics are good, but they're not Etalon good.

I do wish I had the equipment to lap the anvil/spindle faces. That's really the only thing stopping these from being truly good as new.

But, I suppose I need to be realistic. The mics only read to thousandths, and the tolerances required in my little hobby shop aren't aerospace-grade. Pretty sure they'll be perfectly fine as-is.

Doesn't stop me from wanting to, though...

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ExHempKnight OP t1_j92o92l wrote

Reply to comment by tlove01 in "The longest-lived micrometer than can be bought." J.T. Slocomb micrometers and stand, all fully restored by myself. Each mic is between 70-120 years old, and they're all still accurate. by ExHempKnight

It really is. Since I've started this journey of precision work, I've really gained an appreciation for how important the tiniest of distances really are. And that everything is rubber.

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ExHempKnight OP t1_j92m86d wrote

Reply to comment by thewander in "The longest-lived micrometer than can be bought." J.T. Slocomb micrometers and stand, all fully restored by myself. Each mic is between 70-120 years old, and they're all still accurate. by ExHempKnight

You're welcome!

I've thought about taking some classes in my spare time, fill in the gaps that the (probably thousands of) hours of machining YouTube I've watched have left in my knowledge.

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ExHempKnight OP t1_j92m00q wrote

Reply to comment by Occhrome in "The longest-lived micrometer than can be bought." J.T. Slocomb micrometers and stand, all fully restored by myself. Each mic is between 70-120 years old, and they're all still accurate. by ExHempKnight

I'm sure they will, as well. But as old as they are, I'm sure they're a bit worn. I don't need them to be exact, I mostly need to know exactly how off they are, so I can compensate when I calibrate the mics.

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ExHempKnight OP t1_j91tim3 wrote

Reply to comment by GanderAtMyGoose in "The longest-lived micrometer than can be bought." J.T. Slocomb micrometers and stand, all fully restored by myself. Each mic is between 70-120 years old, and they're all still accurate. by ExHempKnight

Those are micrometer standards. They are used to calibrate the mics, to ensure accurate readings. Each mic has a corresponding standard... The 3" standard calibrates the 3-4" mic, and so on (the 0-1" mic calibrates on 0, so it doesn't have/need a standard) The plastic sleeves on each rod are to insulate them from the heat of your hand, which can throw off the calibration.

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ExHempKnight OP t1_j91sxsw wrote

Reply to comment by CR123CR123CR in "The longest-lived micrometer than can be bought." J.T. Slocomb micrometers and stand, all fully restored by myself. Each mic is between 70-120 years old, and they're all still accurate. by ExHempKnight

Thank you! I need to bring the standards to an instrument calibration place, and have them checked. I'm sure they're fine for my little hobby shop, but I'm kinda particular about that stuff.

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ExHempKnight OP t1_j91q8uy wrote

Reply to comment by Zestyclose_Plenty_49 in "The longest-lived micrometer than can be bought." J.T. Slocomb micrometers and stand, all fully restored by myself. Each mic is between 70-120 years old, and they're all still accurate. by ExHempKnight

Thanks a lot! I'm just a basement-shop hobbyist... So I appreciate the compliment from someone who does machine work professionally.

The only thing I'm unable to do with these is properly lap the spindle and anvil faces. If I could do that, they'd be as good as, if not better than, new. But for my purposes, they work great as-is.

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ExHempKnight OP t1_j91ngk0 wrote

Reply to comment by Dominick555 in "The longest-lived micrometer than can be bought." J.T. Slocomb micrometers and stand, all fully restored by myself. Each mic is between 70-120 years old, and they're all still accurate. by ExHempKnight

All the hardware for the stand is original, as far as I know. The wood slats are new, as the stand arrived to me in pretty sad shape. I stripped and repainted the cast iron frames, and polished the nameplate. The rubber bumpers between each mic were dried out and painted over, so I replaced them with pieces of rubber fuel hose.

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