Dial indicator repair

[Sonic EscapeParticipant @sonicescape38234]

I found an old Romanian dial indicator and I want to see if it can be restored. Now it doesn't run smooth. But I have no idea how to open it. The bottom can't be removed. Anybody has any ideas?

[Sonic EscapeParticipant @sonicescape38234]

[Mike HurleyParticipant @mikehurley60381]

Does the front bezel screw onto the main body? Note the small semi cicular cutout in it that may be there for use by some kind of pin spanner across it? It doesn't look as if that is there as a zero-setting adjustment for the scale as it wouldn't seem very easy to use in normal operation.

Edited By Mike Hurley on 05/03/2023 12:20:00

[Sonic EscapeParticipant @sonicescape38234]

The bezel rotates. But it has no thread. I can pull it. But the needles stay in place, they don't come out together with the bezel and dial. If I remove the bezel + dial (they are connected together) then I think the needles will bend.

[Clive FosterParticipant @clivefoster55965]

Deleted

Edited By Clive Foster on 05/03/2023 12:32:40

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Sonic Escape on 05/03/2023 12:10:34:

[…]

The bottom can't be removed. […]

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Given that there is a joint-line visible in that photo ^^^ I find that very surprising

MichaelG.

[Sonic EscapeParticipant @sonicescape38234]

Unfortunately that is not a joint line. It is just a chamfer. Unless it was not painted over. Here is a high res picture:

Dial indicator

[Michael GilliganParticipant @michaelgilligan61133]

O.K. … thanks for the clarification

Very weird … Mmm !

MichaelG.

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Here’s an old Batty one for comparison

Makes life a lot easier !!

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I suppose there could possibly be neatly countersunk screws concealed under that Hammerite paint … a few seconds investigation with a magnet might be worthwhile.

Edited By Michael Gilligan on 05/03/2023 13:11:30

[SillyOldDufferModerator @sillyoldduffer]

Never take one apart, but probably a press-fit, like a watch back. Watches usually have a slot allowing a knife to lever the back off, but replacing it risks breaking the crystal unless a proper press is used.

I'm not sure dial indicators are meant to come apart in a home workshop. Inexpensive ones are replaced when they stop working, and the expensive ones sent off to a specialist repairer, who presumably has the equipment, spares and knowledge needed to do a good job.

Nothing wrong with having a go unless breaking the dial is a disaster.

I see the Makita angle-grinder I bought yesterday was made in Romania. I don't think it's meant to be repaired after I wear it out.

Dave

[Sonic EscapeParticipant @sonicescape38234]

The bezel + dial assembly can be lifted 1mm. Until it touches the needles. And it is pulled back by something elastic. There are no screws covered by paint. I scratched it everywhere.
This indicator could be one of the first items made not to be repaired

[old martParticipant @oldmart]

I would try a screwdriver between the stem and the bezel to see if it starts to move out. If it does, then turn it and lever again. These mechanisms are made to be dismantled, and since the back is one piece, you have to go in at the front. You still need to remove the hands before the dialcan be removed. For the dial, do not use any solvents, try water with a couple of drops of Fairy liquid and a soft tissue with great care. You can use solvents when the dial and pointers are removed, followed by some light oil.

Edited By old mart on 05/03/2023 14:17:28

[HopperParticipant @hopper]

You might have to use a clockmaker's special tool (clock hand remover) to pull the needles off their spindles so you can then pull out the bezel and dial face. Maybe.

Or if you look at that small half-round cut-out on the edge of the bezel and slowly rotate it around the full circle, you might see a tiny little screw revealed that you can undo and that allows the whole assembly to be lifted out together. Maybe. That half-round cutout must be there for some reason. Or is it there to engage with the outer bezel and allow you to rotate the dial?

Edited By Hopper on 05/03/2023 14:24:23

[peak4Participant @peak4]

As per Hopper's comment, you might need to remove the clock's fingers.
Re. the half moon cutout, as you rotate the bezel around the body of the clock, have a look into that cutout.
You might find that in one, or more, positions, it exposes a screw head.
My guess is that there are 3 hidden screws, which you might be able to loosen, not remove, as you rotate the bezel through 360°, and that the 1mm lift is actually a round wobble washer.

Bill

[Michael GilliganParticipant @michaelgilligan61133]

Probably worth linking this for the benefit of future visitors to the thread:

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MichaelG.

[D.A.GodleyParticipant @d-a-godley]

I am not sure if he still offers the service , but Bob Dixon , friend of YouTube’s Doubleboost , did an excellent job on a DTI for me .

[HopperParticipant @hopper]

Nice trick there in the video to pull the hands off without the special tool, using two Q-tips and two screwdrivers.

[Sonic EscapeParticipant @sonicescape38234]

The picture is not so clear but that half round cut on the bezel is actually a dent. Yesterday I decided to try to remove the needles with a tweezer. But before I poured a few drops of WD-40 in the center of the dial. The liquid went inside without having a change to dissolve the markings. I pulled the needles with moderate force but nothing happened. But then I noticed that the indicator works much better. The movement very is smooth. But sometimes it get stuck completely.
Today I tried again to push the plunger and this time it is working fine. Overnight the oil got where it should be. It doesn't hang anymore and the movement is very smooth. WD-40 + time solves many things

[Swarf, Mostly!Participant @swarfmostly]

Posted by D.A.Godley on 05/03/2023 22:15:51:

I am not sure if he still offers the service , but Bob Dixon , friend of YouTube’s Doubleboost , did an excellent job on a DTI for me .

Ditto for me.

Best regards,

Swarf, Mostly!

[Mike PooleParticipant @mikepoole82104]

WD40 tends to dry and go sticky with time so the improvement may not be permanent, it does seem to lead to answer being a clean and lube with a suitable lubricant is what is required to restore your dial gauge.

Mike

[old martParticipant @oldmart]

You give up too easily, two screwdrivers with fine ends would have the pointers off in seconds. Lever together resting on the bezel. There are three, starting with the red cap, then whichever is second down and then the one nearest to the dial. They will have a tendency to go into orbit unless a bit of tissue is resting on top as they are removed

[Grindstone CowboyParticipant @grindstonecowboy]

I'd hazard a guess at the stickiness being on the plunger, rather than the internal mechanism. A bit of petrol or lighter fluid on the plunger whilst working it up and down may solve your problem.

Rob

[roy entwistleParticipant @royentwistle24699]

Never use WD 40 on anything brass.

[Ian PParticipant @ianp]

Posted by roy entwistle on 06/03/2023 22:24:37:

Never use WD 40 on anything brass.

That needs an explanation.

I very rarely use WD40 on anything and I dont even have any in the workshop at the moment but why single out brass?

[roy entwistleParticipant @royentwistle24699]

It forms a gooey mess which is impossible to remove. Ask anyone who repairs long case clocks.

Edited By roy entwistle on 07/03/2023 09:30:17

[Robert Atkinson 2Participant @robertatkinson2]

Late to this, but as others have noted this style of DTI you have to pull the pointer off to remove the dial. They can be very tight.

I recently repaired a N type connector gauge (basically a DTI with custom fittings) and the pointer was very hard to remove. The original issue was that the pointer was fouling the glass with the dial / bezel locked. don't know if it was always tight or the wrong pointer was fitted at some time. I have a good quality watch hand puller and experience using it (used to repair aircraft instruments). More force than I was happy applying to the puller and dial (with a nylon protector disk between dial and puller) did not move it. Heat (soldering iron) or penetrating oil did not help. in the end it took two screwdrivers supportrd on two bars across the bezel shifted it. A strip of sticky tape stuck to the balance end stopped the pointer flying into a corner of the workshop. I had to ream the bore of the pointer boss quite a bit to get it to fit properly.
WD40 is not ideal lubricant for DTIs but see how it goes.

Robert.

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