Mystery DTI

Tidying up my drawers, in preparation for experimenting with foam and papier-mache in organising items in them, I came across this 1.1/2" Mercer G.91 DTI.

The only part that moves is the black bezel, the indicating lever and arm being fixed.

The contact 'pin' is fixed as well, and unscrews.

Any help as to how and where it is used appreciated please.

More photos uploaded into new DTI folder.

Ah, I can insert photos when using the MacBook.

Geoff - Hoping to clear up this mystery.

Hi, Admittedly I haven't a definite answer for you, but I wondered if the contact point would unscrew from the back of the gauge and then screw into the end of the long arm?

Steve.

Hi Ouballie

You may find a small drop of light oil applied to base of the knurled probe on the back will release it. I suspect it is stuck fully pressed in.

Cheers
John

Just found this on Fleabay:- **LINK**

So just to answer my own question _"no"

"The dial moves from the back"

I think John has it right.

Edited By Steamer1915 on 11/06/2013 16:23:55

Edited By Steamer1915 on 11/06/2013 16:24:29

I have a Verdict DTI very similar to your Mercer and used it years ago when setting the cam timing on my Triumph bike engines.

Paul

Geoff,

John & MichaelG,

You both got it in one.

After reading the responses, I loosened the probe enough to get a thumb nail under it, levered and it moved ever so slightly, so as mentioned, it's stuck.

So a little 3in1 as suggested.

Mystery solved.

I did 'manage' to remove the bezel, but quickly got that back.

MichaelG - What exactly do you mean by 'nasty surprise'?

I hesitate/am reluctant to take it apart, as I have visions of all sorts of bits and pieces heading for the nearest black hole, that seem to inhabit all workshops, of whatever size or tidiness.

I wonder if a sonic bath will free the insides.

Will post update.

Windy - Details of how it's used for timing would be appreciated please.

Cheers all.

Geoff - Just about recovered from weekend

Hi Geoff,

I inherited a Mercer G.92. I find it very useful when tramming my milling machine with the dial always facing upward.

Ed.

.

Nasty surprise = furry corrosion

I will post a photo sometime.

MichaelG.

.

P.S.   This is what it should look like

Edited By Michael Gilligan on 11/06/2013 18:56:24

Update.

Since my first post, I have been applying normal as well as 3in1 oil to the plunger, and it has finally today freed enough to be sliding smoothly.

The gauge now appears to be working as designed, but I will continue applying the lighter of the two oils for a while yet, moving the at the same time.

Ta for all the help.

Geoff - If only the same treatment would work for me

Hi Geoff,

Be carefull of the three in one, If left on moving parts for some time it can set like varnish.

Peter.

3 in 1 contains castor oil IIRC.

Neil

Have you tried WD40 or similar release fluid?

George

DON'T USE WD40!!!!!

Sorry for shouting.

WD40 turns into a waxy gooey mess if left for any time. Use it for displacing water (thats what the "WD" is for...Water Displacing), and then wipe up any residue

Up here in 'Straya there is a thin oil called "Inox", available as aerosol or a can. There must be something similar in the UK. Inox is the near perfect stuff for things like this. I suppose the perfect stuff is clock or watch oil.

cheers

Bill

A distant memory says not to use oil on dial gauges, only graphite dust.

Regards

Geoff

Thanks for the warnings!

Graphite dust I have as well as sewing machine oil.

Geoff - Today is workshop day at last

.

Geoff,

Sorry for the delay ... I finally got around to re-sizing some pictures; only to find that I had already done that [side-effects of Anno Domini]

My furry DTI is not the back-plunger style; but it is a Mercer, and the corrosion is fairly typical of one that has suffered condensation.

MichaelG.

Three more pics in the Album.

Thanks for the photos MichaelG.

I had one of these in a small lot of engineering bits & pieces, mine is stuck the same as Geoff's was.

By removing the little screw on the back I've dripped in a little watchmakers oil but I'm not sure exactly how you would use it ? My other dials have either a piston or a little pressure lever but what should this one have to operate it ?

I inherited two smaller versions when clearing a workshop.

have never used them, but am sure that one day, one or the other will come in handy.

At least such clocks avoid the contortions sometimes required to read a plunger clock. Tramming a mill is one such time.

Most of the time the clock of choice is a Verdict finger clock

.(Probably because I am just too idle to dig out and set up any other! )

Howard