Stuck Dial Gauge

You have no alternative now except to dismantle the gauge. This is a simple mechanism and clean all parts thoroughly with a solvent, I recommend brake cleaner or lighter fuel. Take care with both. If you have an ultrasonic all the better.

Re-assemble with the barest of lub, here watch oil is best. ( A Ptfe lub is OK but again sparingly, Ptfe searches out dirt and will keep parts free from dirt in use.) Do not use grease of any sort. When assembling set the rack and gear so no backlash occurs.

Clive

Photos of the mechanism will be job for tomorrow, will hang on in case the pictures give any further ideas before dismantling as my pound of sausages shape and sized hands could do damage to the poor thing.

35 pictures it took to get these.

Master of the blurred photo me

Those three came-out well, Dod

And yes, the movement is much less corroded than mine:

... But, I notice there is some corrosion on your plate retaining screws; so I suspect you will find more when you strip it down.

It looks like a Mercer movement ... is it ?

MichaelG.

Edited By Michael Gilligan on 17/04/2016 21:46:39

Hulloo Michael G

Yup, its a Mercer, is that a good or bad thing?

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Assuming it's 'of a certain age' ... Definitely a Good Thing.

See here and here

By the looks of yours, it would be well-worth working on.

MichaelG.

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That one of mine is too far gone [the plates are very pitted]

Edited By Michael Gilligan on 18/04/2016 20:31:02

Them 3 photos were the only usable ones from the 35 I took, great things digital cameras as that would have cost a fortune if I had had them developed.

I think the gauge may be aged from round about 1970 ish.

Thanks for the advice, looks like a strip down job so will have to look out the small screwdrivers and magnifying glass.

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Definitely worth trying to fix it then ... Built by Chronometer makers !!

I remember marvelling at the wheel-cutting machine, when I visited them in St Albans.

MichaelG.

If it is a tenth thou (0.0001" resolution Mercer , it may be beyond redemption. In my previous employment I used to use calibrated equipment for checking rebuilt CNC machines & found that the high resolution Mercer guages got sticky and unreliable for no apparent reason. These were cosseted, final inspection only guages, independantly certified & kept in original boxes until required, yet they would not give reliable results after a couple of uses. I cannot recall having had one sucessfully repaired.

I moved to a 0.001 mm resolution Mitutoyo, the independant calibration certificate for which showed 0.001 mm error over it's 1 mm stroke - it may have been better than that, as IIRC there was an uncertainty of measurement given of 0.001 mm. That guage always worked when required - as has every Mitutoyo dial guage I have used.

Nigel B

Made in St Albans. According to the dial face its a 0.01mm resolution so much finer than the ba hair accuracy I'm used to working to.

Clue :- when turning gauge face up to refresh memory of the accuracy there is a distinct click, same when turning to look into back, happens every time gauge is turned over and didn't hear that before exposing to solvents.

I would attempt to repair it anyway as I get great satisfaction in successfully repairing basket cases of anything mechanical and nearly as much if a repair does not succeed.

Edited By Dod on 19/04/2016 21:08:30

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That's the attitude.

... Best of luck with it.

MichaelG.

It works, dunno what was up with it, dismantled it and didnt see anything amiss or messy so cleaned anyway and reassembled it. Found the rack drops under gravity before fitting the spring so a happy bunny.

And I am not going to correct the deliberate mistake

It was just craving some attention.

MichaelG.

I had a sticking Blake coaxial indicator. After getting it cleaned out and freed up using Shellite or in English terms liquid Naptha. I lubricated it with unscented baby oil , ( it says it is paraffin oil)sparingly on the jewels and a little on the bronze bush. When oiling the jewels you want just a very tiny amount so that it's surface tension keeps it in place. Too big of a drop and the surface tension can't keep it there and it will run away or off the jewel dimple. In clock making there a re lots of different grades of lubricants.

It's been a while now since using it and used it last week, and it was fine and free in it's movement.

Neil

That second link led me to here **LINK**

It's pretty scathing of many manufacturers/brands.

I've half a dozen dial / lever mechanical indicators at my disposal, (Mercer, Mitutoyo and Starrett iirc) a couple near untouched from the factory and others that were more beat up cleaned and serviced a decade or more ago by a watchmaker friend, but last I checked quite a few had gone stiff despite being in what I'd call quite reasonable storage conditions - in a toolmakers cabinet, in a centrally heated area with VCI paper in the drawer. There is certainly no rust on anything else in there

I've long lost touch with the watchmaker friend, so this time it's going to be a DIY job with, I suspect, a dab of brake cleaner as my eyes are not up to dismantling,