[Metrology] Stocking up the home shop?

My favorite tool is my Mitutoyo Digimatic calipers.

I've got a Mitutoyo digital "coolant-proof" blah blah set of calipers. I honestly don't even remember what they look like, as I find myself reaching for my Starrett dial calipers. I have no reason for this, I wouldn't even call it a "preference," just how it is...because..? hah

Second most used is my Mitutoyo absolute micrometer. This was a gradutation gift from my dad.

I think I drooled a little at this mic. I've got some Starretts (all used/cheap ebay finds) that run so tight you can't even use the thimble to close it on open space, and I splurged on a B&S .0001, but boy...That's something else.

For measuring bores, I use a Mitutoyo 155-903 set of telescoping bore gages. These are a must have. For smaller bores I recommend either split tip style bore gauges or gauge pins.

I do need to pick up telescoping gauges for sure, but they slip my mind. I have a...1-2(?) inside mic, and split ball type small hole gauges, but there are major gaps between the coverage of these.

New for the lathe are a set of thread measuring wires, metric and imperial theard gauges, and a master precision level.

I'm prowling for thread wires for a decent deal. I don't often find myself dabbling in metric threads (though as I write this, I'm realizing I own a BMW, Toyota, and a VW :eek:) so I haven't bought in to metric thread stuff yet. I've got a standard machinist level good to .005 in 12" - how often do you find yourself actually using the master level? I debate the need for one, but honestly don't know. Should I be watching for a deal so I don't miss it?

I didn't take pictures of the various setup and layout blocks that I use, but having a number of decent quality 1-2-3 blocks, v blocks, and angle plates is a must. I also have a high precision cylindrical square for tramming my mill. I'm sure I forgot others but these are the main ones.

This is somewhere I'm 100% lacking. I have no v-blocks, no angle plates, and my only 123 blocks are "almost" 123 blocks I was progressing on in class years ago, when someone forgot to turn on power to the magnetic chuck on the surface grinder. They detonated a wheel, smashed the daylights out of the chuck, and destroyed a couple relatively minor parts of the machine, taking it out of commission before I got past 123.001 - 123.003 blocks or so. At least they're square and parallel.

IMO, any surface plate that you have not personally kept track of since its last calibration should be re-calibrated before any serious use.

I agree, and it's something that's been keeping me from pouncing on any surface blocks I see pop up for sale. I've only casually glanced, but I have no idea even what ballpark I should expect to pay to inspect and/or lap a plate of any given size.

do we need to fret over the flatness of a surface plate that we do layout on with a height gage that is graduated in whole thousandths and never has been calibrated and that the marks it makes on workpieces are machined to by eye?
It is one thing to need high accuracy of a surface plate that may be used as a scraping reference surface, and quite another for one used in day to day layout tasks. I have never felt the need for pin gages, and seldom even use drill blanks; perfect sizing of parts that we machine is seldom necessary, FIT is what IS necessary.

I agree, to an extent. As has been mentioned already - totally depends what you're doing. I can honestly say I've never laid anything out and machined to the layout marks by eye, outside of school. You make an extremely valid point about fit being the critical factor, not the numbers, but that's also pretty limiting in terms of interchangeability. My perspective on the topic is twofold: one; I can always relax my standards, if I'm capable of holding them tight - if fit is all that matters, I can match machine something pretty easily. If my tooling is only good enough to match machine though, I'm going to struggle when I try to bore a bearing race in a transfer case housing or chamber a rifle barrel. Two; I'm a "train how you fight" advocate, and I do enough machine work to +/- 0.0005" during my day job that I feel like I'd just be inviting trouble if I came home to a "this is good enough" attitude in my own shop.

There's also the fact that I'm the type of person who needs things "just so," and I'd crumble if I knew my personal shop wasn't up to snuff.

A fair share of the work on my personal projects list calls for tenths accuracies, hence looking for advice on metrology equipment.

I'm also of the opinion that most people wildly exaggerate the complexities of high-precision measurements. It's just like talking politics - people pick one side of the fence and they cherry pick facts and stories to make their point. Sure, measuring to tenths and beyond is very dependent on outside factors, but as benmychree said, fit is what's important. Measuring in tenths for axial runout or parallel alignment could not care less about the ambient temperature, but your final product may very well care if you "only" measured in full thousandths. But I digress.

Keep the tips coming! I appreciate everything so far!
 
Back
Top