Early Ebay Xmas delivery

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PeterT

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I've been watching & lurking for some time now, finally pulled the trigger on an indicating micrometer & it arrived today. For 125 USD I'm happy. It is the specific style I was after. It appears to have seen little use. Everything functions is smooth, no rust. More like thickened oil or stain. The indicating needle (not showing) repeats very nicely. It has a light ID# engraved but hardly noticeable. I thought the bezel was cracked but on closer inspection it looks to be glue smear which mostly came off. After I took this pic I removed the cover I saw what might be original rubbery type glue which I removed & it looks better. I'm wondering if it is the stock bezel with degrading adhesive or someone made a replacement a some point. I'm sure I could cut something out of 1mm plastic if it bothered me.

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Darren

Darren

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Thats pretty mint. I'd imagine the accuracy is the same as a good tenths mic, just much faster to get the reading?
 
DavidR8

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Very cool. Never seen one like that before. But that's not saying much!
 
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PeterT

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Darren said:
Thats pretty mint. I'd imagine the accuracy is the same as a good tenths mic, just much faster to get the reading?
Click to expand...

The way it works is you set the mic to a known or target dimension & lock the collar. Then to measure part, push the little plunger on LHS adjacent to dial which releases what is normally the fixed anvil. Retracy to measure & now the teeny tiny needle (not showing in my pic) comes into window & shows you + or - relative to that target, each increment is a tenth. So where this excels (or at least I've convinced myself would be nice) is say lapping a shaft & you are taking spot measurements up & down the length. Because it's analog & because its visual, I think it will convey information better than 0.1234, 0.1238, 0.1230... from a digital reading tenths mic. Similarly I guess if you were comparing a bunch of parts to be within spec (the red book end needles can be set. My pic shows +/- 0.0005" range.

The modern ones look like this & I kind of like the dial face more. But they go for 1K
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PeterT

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For some reason mine did not come with a case which is odd. Not a show stopper, I'll figure something out.
 
Darren

Darren

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I;ve seen them before, but never used one. From my understanding of your explanation, it would be a faster visual way of seeing taper in a shaft that you just turned. Pretty cool.
 
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PeterT

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Darren said:
From my understanding of your explanation, it would be a faster visual way of seeing taper in a shaft that you just turned.
Click to expand...
Yes but with the caveat that the needle shows deviation relative to whatever reference diameter you locked the collar. So it acts just like a regular mic until that point, the barrel lines + vernier scale will tell you 0.5678", but the needle tells you +/- number of tenths from 0.5678. Its less about absolute & more about relative if that makes sense. Often they are used with gage block stacks as reference. So only because you mentioned taper, if it was outside the ~0.002 total needle range, then the needle would not be able to come into play. For example one end was 0.567 & the other was 0.564, doesn't matter which reference you lock on, dif = 0.003", too much for dial range.

Now I wish I took a pic with the needle in the display, I'll do it next time. Its very fine. About the width of a tenth tick thickness. So actually you are measuring sub tenths with some repeated certainty.
 
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PeterT

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There 'just might be' a bigger brother coming too LOL. Weird, seems like everything I looked this past year was expensive, or very used or both. But recently the planets aligned & some nice prospects came up.

I noticed there are proportionately more metric indicating mics available. Often times via eastern block sellers & many good quality German/Swiss/Other brands which seem to be more predominant than Mitutoyo. I was looking at some Mahr's for example. Perhaps a bit less convenient for us IMP types, but not really. Just knowing what MET range represents in tenths & where the part measurement lands is mostly what we are after. Just set the red range needles accordingly. Most MET indicating mics are finer increment. Very common is 0.001mm increment = 0.0000397" (~0.4 tenths between ticks)

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RobinHood

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A big portion of the world operates in the Metric System. Even though some of the initial metrology trail blazing was related to the “English System“ with Maudslay, Watts and Whitworth being just a few of the heavy hitters. The Natural History / Science Museum in London has an excellent collection of some of the early metrology equipment.

Found this website on precision instruments; particularly like their Resources section.


Here is a pdf of “A Brief History of the Micrometer” by Mitutoyo.
 

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Susquatch

Susquatch

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I enjoyed it too @RobinHood. The thing about books is that you can read at your own speed zipping through content of less interest, slowing to absorb difficult content, and pausing without physical constraints. In other words, THANK YOU VERY MUCH!

I've not seen that next generation QuantuMike micrometer they spoke of before. On the surface, it seems like it would be less accurate than older generation mics. But I trust Mitutoyo to do it right. If anyone can, they can. I can't wait to try one
 
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Mcgyver

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Way to go Peter, I've got the same mics, very handy. I've also got an Etalon, a Polish one and a Mahr. Like most indicators, there's a hair spring in them that can get gunked up when guys think they should be lubbing them, but if yours aren't sticky you are good to go!

Darren said:
Thats pretty mint. I'd imagine the accuracy is the same as a good tenths mic, just much faster to get the reading?
Click to expand...

They are quite a bit more accurate than a tenths mic, just based the distance the indicator hand/needle has to travel vs the distance the barrel has to move to line up the next ,mark on the vernier. I often set them with gauge blocks and then use them as a snap gauge, easy to see sub tenths distances of needle movement, extrapolating between the graduations.
 
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PeterT

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Coincidental you mention lubrication (lack thereof) @Mcgyver it came up in discussion on another group. Someone referenced some distant Starrett servicing instructions basically stating (if I understood correctly) no internal oil on bearing/shaft surfaces, they were chosen & engineered to run 'dry' & secondary risk to munging the hair spring. This mic has the same yellowing silicon like gasket goop between face & body. I'm guessing to seal off dust & debris. I carefully removed the remnants thinking chance of bits falling inward are higher than partial protection. Any recs on what to use? Any goops I have used in the past would be too tenacious, unless maybe I applied a neat, thin paint coat bead to back cover edge & allowed to dry first.

Jeweler's tip I seem to have to re-learn occasionally when working with teeny fasteners & parts. Work over a soft cloth like terry towel, not a hard table surface. If parts roll & go sproing onto the dark cement floor it can permanently go bye-bye go to the Land of left dryer socks. Luckily on the 5th dustpan sweep, I found it 2m under a table leg. Sheesh.

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PeterT

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Here is prior related lubrication discussion on this forum.

canadianhobbymetalworkers.com

Dial indicator clean and lube

Since Blondihacks posted her video on Repairing Dial Indicators, I've cleaned and lubed a couple of really old ones in my possession. Repairing Dial Indicators - Diagnosing, Fixing, and How They Work! Among my auction haul from a couple of days ago was a kind of nifty back plunge Ames. As...
canadianhobbymetalworkers.com canadianhobbymetalworkers.com
 
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Mcgyver

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Ah, picking through floor sweepings, what a way to spend a Sunday!

I recall an inline device with a stainless steel screen used with a vacuum (might have been Frank Ford who made it, can't remember) but I was always fearful watch screws were too small to be caught. Instead I use a hand held vac (affectionately referred to as the bust duster) then dump the bag on the bench. My watchmakers bench has glass on three sides and over top as well as the standard cloth pull out, and the standard groove at the front to catch rolling parts. that helps a lot

A new idea (for me anyway) is to us a silicon tray, the sort pet owners buy to put the dishses on. the rubber stops some bouncing, but the key feature is a a lip molding all the way around it. Don't work on models without one!


You can see it action toward the end of the gasket video i did.


PeterT said:
Coincidental you mention lubrication (lack thereof) @Mcgyver it came up in discussion on another group. S
Click to expand...

I've long advocated that for all indicators, rational is here for example. https://canadianhobbymetalworkers.com/threads/dial-indicator-clean-and-lube.4181/#post-55911

Edit, I must be slow today, i see you added the link
 
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