Creative misuse of tools to measure with

Apologies to whoever finds these obvious or trivial, feel free to roll your eyes and move on...
I'm also unsure whether these qualify as metrology, or whether ordinary shop measuring belongs in General, so feel free to move this, not that you need my permission, Mr Moderator. Sir.

1) Adjustable parallels, if you have a comprehensive set with generous overlaps, are SO useful for measuring between faces or inside slots and anywhere other devices won't reach

2) A set of drills in 0.1mm increments (or if you like looking up charts, a Number/Letter set): the butt end is great for measuring small gaps (once again, especially when hard to reach)
I make sure these are NEVER used in dodgy chucks, only an Albrecht or ER collet, so the shanks stay un-munted

-on edit - I normally use this only to get within 0.1mm, partly because of the shank bearing punched letters and numbers, it doesn't qualify as a high precision strategy.
As PeteM points out below, if you're after precision, you can't assume the shank is the same as the nominal size.
I tend to use feeler gauges if it's fussyish. If it's a gap between machine elements which are (or can be) pulled together by bolts to a defined location, I've used lead sheet, solder wire for thinner, or plastigage for thinnest. I find I usually have to recalibrate plastigage rather than relying on the width scale shown on the package: I use a large, rigid vernier caliper, but a mic with a non-rotating anvil would be beter.

3) For slightly bigger gaps: I don't know about you, but I use small hole gauges like miniature inside calipers, ie measuring between faces (as when working out how thick a spacer to make) more often than I use them for holes

I'm talking about the ones like two stub-nosed spoons back-to-back, with a knurled adjuster towing a conical spreader between'em. Make GREAT calipers. (Much more rigid than a spring-bow)

4) I get frustrated turning smallish ID work where the tolerance permits a slide caliper.

I'm talking about the airspace used by all the unused bits and pieces: ie OD and Depth stuff, meaning (inter alia) the cross slide has to be moved way back and I have to be careful not to poke an eye out (getting clumsy, but on the bright side I'm getting REALLY good at catching things I've fumbled and dropped ...)

In some cases, with internal shoulders, the unwieldiness means you just can't bring the inside jaws to bear atall.

When buying another lathe a while ago, I acquired a whole bunch of great stuff I didn't know was included, one being a nice little 6" vernier I didn't really need, so before I could bond with it, I went straight over to the 1mm cutoff wheel on the dble ended grinder and removed all the bits which get in the way. Magic !

I'm sure you can probably buy specialised ID calipers, but not for free...

5) Balls !

Whenever I scrap a decent sized ball race, unless it's really stuffed and they're no longer round enough for my purposes, I save the balls (and the rings, but that's another story)

When I have to measure a female taper, it's just a matter of choosing a suitable small and big ball, a magnet to fish them out (if the taper mouth is above the tail end) and a depth mic.

Also handy for measuring to a conical-bottomed hole, depth of a non-std woodruff slot, etc

Good ideas, thanks.

One possible gotcha with using the drill bits as plug gages is that some brands are ground with clearance at the shank. The cutting edge is supposed to be on size, but the shank has a slightly smaller diameter. The good news is that serviceable plug gages are now pretty cheap to buy. I suppose the other good news is that cheaper drill bits tend not to have the clearance and, of course, it's easy to mic the diameter and know for sure.

Troup said:

5) Balls !

When I have to measure a female taper, it's just a matter of choosing a suitable small and big ball, a magnet to fish them out (if the taper mouth is above the tail end) and a depth mic.

Click to expand...

I like how you use your balls!

Great tip, that one's getting filed away.

Matt@RFR said:

I like how you use your balls!

Click to expand...

That would temporarily stop the chatter round the smoko table. A few manly eyebrows might even be raised before conversation resumed....


I forgot another great attribute of adjustable parallels, which I'm sure the inventors did not anticipate.
Until I got a set (a couple of sets, actually) I was always having to shag about to measure the depth of holes and steps in the area under and to the right of the quill of my vertical mill, where the fine feed gearbox and spider drastically impact on headroom.

Then I realised if I stood an adjustable parallel up on end, with the screw tension set so I could still smoothly slide one piece to overhang the other down into the hole, it makes a dinky little depth gauge, particularly for shallowish holes or for steps. And of course you've automatically got a range of sizes.

Drill shanks as "poor man's plug gage" works. Measure
the shank though, as mentioned they are never the size
the drill is listed as.

Also any number stamping on the shank will mess up the
utility....

Jim