Tool gloat - why I love ebay

I have couple of Mitutoyo bore gauges that always bring a smile to my face when I use them. One is 18-35mm and the other is 35-60mm. They have a three-point device at the end, and then a long plunger-in-a-handle and at the top is a dial indicator. You set the zero with a micrometer, then gauge your bore. It makes it easy to match a shaft and a bore to a few microns.

Anyway, for a while now I have been looking out for a smaller set, to cover 10-18mm. This turned up on Ebay a couple of weeks ago, with an inaccurate description. I was the only bidder and got it for 29 Euros including shipping:



It just arrived tonight. When I opened it, I found that it has never been used. The feeler fingers still had the factory wax protective coatings (which I have removed in the photo above). All the accessories are there, including the extension bar, the holder to keep this at a fixed distance from the mouth of the bore, etc. There was a brown sheet of VPCI paper inside, so nothing is corroded. The indicator is 2 microns/division, and runs as smooth as could be. The shiny parts are ground and polished steel, the darker parts are blued steel (apart from the hand grip, which is dense rubber foam to isolate it from hand heat). The instruction manual dates this from the DDR (former East Germany) in 1989. And all of this in a perfectly-crafted finger jointed box with a molded foam rubber fitted lining.

I'll get to use this soon because I have to turn a 4-step pulley from some cast iron, and need to match the bore closely to the motor shaft.

Congratulations, Bruce!

I've got the same set, but don't have measuring rings (that are needed because of the 3-point-measuring principle).
One detail I like much: the scale of the dial indicator can be rotated very sensitive by a small wheel at the side of the case.

Do you own the set of measuring rings?


Last week I had luck, too; a "digital column display unit" Marposs E4N_v2.3 [0,1 µm resolution (= 0.000004") on one channel] with 3 inductive probes for 21,50 € (=26 $):
Marposs E4N Saulenanzeigesystem mit verschiedene Zubehoren (laborauflosung) | eBay

But only one inductive linear probe does fit; all others seems to be too old and all the connectors need modification to use it.

If I would buy a Marposs E4N again, I would look for firmware version 2.7 or higher, because is has more functions.

Cheers,
Karl

ballen said:

I have couple of Mitutoyo bore gauges that always bring a smile to my face when I use them. One is 18-35mm and the other is 35-60mm. They have a three-point device at the end, and then a long plunger-in-a-handle and at the top is a dial indicator. You set the zero with a micrometer, then gauge your bore. It makes it easy to match a shaft and a bore to a few microns.

Click to expand...

You seem to have made a good purchase so CONGRATS. I'm wondering though how you set the zero with a micrometer on a 3 point instrument.

Hi Bruce,

sorry, I supposed that your new set of bore gauges would work with 3-point measuring principle. Meanwhile I remember, that these set have been available with 2-point measuring heads.

There are pictures of the version with 3-point measuring heads:
forum.zerspanungsbude.net • Thema anzeigen - Hilfe: Unbekanntes Messgerat
forum.zerspanungsbude.net • Thema anzeigen - Hilfe: Unbekanntes Messgerat

Actual your version has the 2-point measuring heads.

Cheers,
Karl

Karl, you were correct (unfortunately) in your earlier post. What I got is the true 3-point version: there is a "flat" on one side of each measuring probe or finger. So these gauges can not be used to directly compared a bore ID to a gauge blocks or a micrometer. I would need a (large!) set of calibrated ring gauges, which I don't have.

Gordon, you are also correct. I realise now that the Mitutoyo 511-133 and similar bore gauges that I like so much are actually 2-point instruments which have an "equalizing" mechanism which helps guide the two points to antipodal points on the bore.

I can still use these gauges for the pulley that I need to make, because I am reproducing a damaged pulley, so can compare the bores. But I will keep an eye out for a 2-point device, because for me that's more useful.

Someone told me, to put a ball at the end of the hole (ball diameter larger than hole diameter) to make a 2-point version from this 3-point version. For temporary use, some grease should work to hold the ball stick in place. I didn't test this method.

For reproducing existing holes, I used it several times successfully.

Once, a friend gave me a ring gauge to make a part for him.

It's alwasy fun to work with this measuring device, because it shows reproducable results.

For some kind of bearings, there are rings available with defined inner diameters. Perhaps such rings could be used instead of more expensive calibrated ring gauges.

CharlyDE said:

Someone told me, to put a ball at the end of the hole (ball diameter larger than hole diameter) to make a 2-point version from this 3-point version. For temporary use, some grease should work to hold the ball stick in place.

Click to expand...

That is a GREAT idea, I will try it! I have an "assortment box" of precision bearing balls of various diameters so should be able to find ones that are the right diameter. If this works well it might be a good "permanent" modification, meaning to attach the bearing ball with a drop of cyanoacrylate adhesive. That would make the ball easily removable without doing damage to the device.

Hi first time ! Be gentle
Ebay tool gloat
Carl Zeiss metroscope Parts
Spotless £120

Drew ultra said:

Hi first time ! Be gentle
Ebay tool gloat
Carl Zeiss metroscope Parts
Spotless £120

Click to expand...

A picture is always nice

Drew ultra said:

Ebay tool gloat
Carl Zeiss metroscope Parts
Spotless £120

Click to expand...

Not a gloat without photos


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ballen said:

That is a GREAT idea, I will try it! I have an "assortment box" of precision bearing balls of various diameters so should be able to find ones that are the right diameter. If this works well it might be a good "permanent" modification, meaning to attach the bearing ball with a drop of cyanoacrylate adhesive.

Click to expand...

I needed to measure some 15, 16 and 17mm bores, and so I got to try out the gauges with a bearing ball added to convert them to a 2-point device. I used superglue to hold on the balls, and it worked perfectly.

Hi Bruce,

well made!

Thank you for the response.

If necessary, I will try it some day, too.

Do you remember the size of the bearing balls?

Cheers,
Karl