Dial Indicators, the cleaning & lubrication of same

[Kludge]

While I'm familiar with the innards of watches and know that dial indicators aren't much different, has anyone here had any experience with their maintenance before I open one up. It's a lovely older one made into a micrometer good to 5mm. Right now, it's sticking and it feels like there's some dirt in the works or maybe a damaged wheel ... er, gear. In any case, I want to open it up and see if it's fixable.

IF I ruin it, I'm not really out any $$$ but I'd prefer not doing that since it's a pretty cool tool. So, if anyone's got any hints, tips, wisdom or the like, I'd really apreciate the help.

BEst regards,

Kludge

 

[Philjoe5]

I've had Dial Indicators stick, especially when I'm using them near my machines while cutting cast iron. I put a drop of very light oil on the indicator rod and work it back and forth and that brings it back to life. I'm still using some of the cheap ones for 3+ years now and haven't had to toss one.

Cheers,
Phil

 

[wareagle]

I happen the have a shop nearby that does just that; they clean and calibrate measuring instruments for the area's manufacturing and machining industry. I had them rebuild a Starrett Last Word Indicator for me a while back, and the nice folks there told me that the key to having these things work reliably was to keep them free of debris and to only use a light instrument oil on the mechanisms. He went on to say that the most sure fire way of taking one down is using the wrong lubricant on it.

Not sure that I answered your question, but that is the bit of info that I have to share!

 

[Circlip]

Yer've done watches Kludge so you know where NOT to get oil, same with DI's. I've bitsed and soaked/flushed with Carbon Tet. and just re-oiled the pivots, You've got all the gear.
Regards Ian.

 

[Andrewinpopayan]

Cleaning out with fluids is fraught with 3 dangers,


1. does the fluid eat the bezel?
2. does the fliud eat the dial markings?
3. does the fluid leave any residue?

Lighter fluid (naptha) is a really good solvent / flushing agent but it will attack paint and some plastics.

Trichloroethylene (dry cleaning fliud) is the "par excellence" shifter of almost any crud, but will also attack bezel and certainly eat the markings. Use it in an airbrush outside in the fresh and away from any sources of ignition, collect the used fluid that runs off into a clean jar, leave the fluid to evaporate off and look at all the bits of crud that settles at the bottom.

I believe (I will certainly be corrected here on this site :-X) that the internals should be like the inside of a watch or a clock), NO lubricants whatsoever and just a trace of dry lube on the plunger.

 

[Circlip]

Yep Andrew, solvents do eat bezels and dials, that's why I said "Bitzed". Kludge has repaired watches so does know where to and not to oil. Pivots on watches and clocks are always oiled, but not Blathered in it.
Regards Ian.

 

[Kludge]

key to having these things work reliably was to keep them free of debris and to only use a light instrument oil on the mechanisms. He went on to say that the most sure fire way of taking one down is using the wrong lubricant on it.

That sounds about right. I have no idea about the DI's history so I don't know what I'll find inside but that sounds like what I would hope would be the proper fixes. I don't have instrument oil but I do have watch oil, natural and synthetic, which is pretty much the same thing just under a different name.

I remember one "hotshot" who decided 3-in-1 would be good for what ailed a DI in a hanger I worked in. He all but poured it in the mechanism after taking the cover off. It never worked right again.

BEst regards,

Kludge

 

[Circlip]

Plunger types have a rack and pinnion, lever types have a long pitch "Screw" shaft rotated with a lever.
Regards Ian

 

[Kludge]

Cleaning out with fluids is fraught with 3 dangers,

As CC said, I've got time repairing watches so have a real good idea what I'm going to run into. I'd just hoped someone had already done one and I could catch a tip or two before I open it up.

The cleaner I use is a solution not unlike that used in ultrasonic jewelry cleaners which is a very mild detergent that doesn't really attack anything but is wonderful for removing crud including old oil. After that, a water rinse and drying with lint-free cloth, watch paper (also lint free), saw dust and/or air. Since I live 50 yards from the ocean, I'm subject to salt air so when I'm not working on a watch (or similar mechanism) the parts are kept in a container with silica gel to keep them dry until it's all assembled again.

I believe (I will certainly be corrected here on this site :-X) that the internals should be like the inside of a watch or a clock), NO lubricants whatsoever and just a trace of dry lube on the plunger.

The only ones that should be kept dry inside are digitals.

The three major (and common) sins related to lubrication are wrong lubricant, over lubrication and lubrication without cleaning first. I use lubricants especially made for watches including the grease used to keep dust out of stems. The lubricators I use for watch work are basically very thin stiff wires with handles on them which deliver less than a drop where they touch the movements. WAY less than a drop. And I do a complete tear down (Okay, I don't remove the hairspring from the balance wheel or its bridge ... but neither does anyone else unless something there is broken!) and clean before reassembling the mechanism ... which is when it's also re-lubricated.

I'm not sure what I'm going to use on the plunger yet. It should be lubricated but that can lead to the possibility of crud geting into the mechanism again and I'd really not like that. Oh, well ... I'll figure something out.

Best regards,

Kludge

 

[Kludge]

Plunger types have a rack and pinnion, lever types have a long pitch "Screw" shaft rotated with a lever.

Cool! I didn't know that. Mahalo nui loa!

All the ones I have now are plunger type but if I run into a lever tye, I'll keep that in mind.

Best regards,

Kludge

 

[rake60]

The indicators I use at work and at home are all Mitutoyo.
The ones use at home are simply old work indicators that have
served their duty and have been retired to less demanding shop.

I can honestly say that I've damaged, broken or destroyed every one
I've owned.
I've knocked them off machines with an elbow or sleeve cuff,
filled them up with coolant or cutting oil, smacked them with a 4
pound hammer while indicating the free hanging end of a long part in
and even forgot once that I had one on top of a 5 foot boring ram.
The 10 foot drop to the concrete didn't do it any good at all! :

Do you have any idea how long it take for a $100 indicator on a $95 mag base
to fall 10 feet? It's enough time to say words that would fill a children's book.
I doubt any parent would allow their child to read it!

They were all repaired except for that last example.
When they are dropped or hit the stylus needle will often bend a little
causing it to bind. A little gentle thumb pressure will often cure that.

At work we have a man who does the repairs, cleaning and calibration.
At home I use aresol electrical contact cleaner to flush them out, then
WD40 applied with the tip of a tooth pick on the bearings only for
lubrication.

Rick

 

[Kludge]

I can honestly say that I've damaged, broken or destroyed every one
I've owned.

Memo to me: Do not loan Rick recision equipment. ;D

The 10 foot drop to the concrete didn't do it any good at all! :

I think that even exceeds Mil-Std testing requirements.

Do you have any idea how long it take for a $100 indicator on a $95 mag base
to fall 10 feet? It's enough time to say words that would fill a children's book.
I doubt any parent would allow their child to read it!

Have you considered eBay cheapies?

I've had that sort of language explosion. Wound up going into a few foreign languages when English wasn't adequate. But what struck fear in everyone's heart was when I went silent. I leave the details of the mayhem that ensued to your imagination.

At home I use aresol electrical contact cleaner to flush them out, then
WD40 applied with the tip of a tooth pick on the bearings only for
lubrication.

Which is probably adequate. I prefer to get into the mechanisms so will do what my watch repair instincts say. It's just a difference of approach.

Best regards,

Kludge

 

[Hilmar]

Kludg,
besides a few gears may be 3 or 4 and a rack,watch out for a very small spring sitting on a gear to take the backlash out. It is a round flat spring like in a watch on the Do Hickey which goes back and fort, not the main spring. I never found out how to set that thing. I toke some apart and before I could catch it to count the turns or the gear position the thing jumps out of position. It is usually on the needle gear and it take only the sligthes movement and it is all over. I just set them by the seat of the pants.
Hilmar

 

[Kludge]

besides a few gears may be 3 or 4 and a rack,watch out for a very small spring sitting on a gear to take the backlash out. It is a round flat spring like in a watch on the Do Hickey which goes back and fort, not the main spring.

That would be the balance wheel and hair spring, which are evil by nature anyway.

I never found out how to set that thing. I toke some apart and before I could catch it to count the turns or the gear position the thing jumps out of position.

Oh, ick. Doncha just hate when that happens? Thanks for the heads up on this. I'll keep my eyes open for this and make sure I catch it before it becomes a Problem.

It is usually on the needle gear and it take only the sligthes movement and it is all over. I just set them by the seat of the pants.

If its whole purpose in life is preloading the mechanism to allow the plunger to return to the rest position, it probably won't need a lot of tension as long as everything else is happy. THis is kind of like the rewind spring in a tape measure but on a reallly small scale.

Again, thank you for the heads up. That will save me some seriously embarrassing moments and bad words.

Best regards,

Kludge

 

[Hilmar]

Quote from Kludge:

If its whole purpose in life is preloading the mechanism to allow the plunger to return to the rest position, it probably won't need a lot of tension as long as everything else is happy. This is kind of like the rewind spring in a tape measure but on a really small scale.

No,that one is usually a larger and a regular pull spring ( Coil ) to bring the plunger back to
the rest position. The one I am talking about is the hair spring. it's purpose is to get the backlash out of the gears so that the needle is allways in the same position.
I am talking about two springs.
Hilmar

 

[Kludge]

No,that one is usually a larger and a regular pull spring ( Coil ) to bring the plunger back to
the rest position. The one I am talking about is the hair spring. it's purpose is to get the backlash out of the gears so that the needle is allways in the same position.
I am talking about two springs.

Oh. Ummm ... oh. I wonder if this works kind of like the anti-backlash mechanism on a dial vernier. It gives me something more to think about when the rust experiment's done and I can turn my full attention to the dial indicator.

Thanks for the correction, Hilmar.

Best regards,

Kludge ... who has added another note to the list of things to watch for inside.

 

[Hilmar]

Exactly ! We are talking the plunger and some lever type!
Hilmar

 

[Kludge]

Exactly ! We are talking the plunger and some lever type!

Cool. A picture of the innards is slowly taking shape before I open the unit up which will reduce the odds of any major surprises.

This is the opposite of a watch's hairspring. It has to be completely neutral when the watch is put together which should put it dead center on the fork lever (part of the escapement.) Unfortunately when it's removed for cleaning, which means the balance wheel and balance bridge go with it, it can be damaged and it no longer centers properly. That's when it becomes a demon child for someone like me (fat fingers, occasional tremors & slowly failing eyesight) to get it right again. Thankfully, I am blessed with huge quantities of patience and a very large hammer. ;D

Thank you again for your assistance.

BEst regards,

Kludge

 

[rake60]

Most will look very much like this inside.

There isn't much there to deal with.

Rick

 

[Kludge]

Most will look very much like this inside.

A picture's worth a thousand words! :bow:

Many thanks, Rick. Many problems are now solved and now I can go in after the rust experiment without any major issues.

Best regards,

Kludge