Mercer dial indicator

[I.M. OUTAHEREParticipant @i-m-outahere]

Hi, i recently picked up this Mercer dial indicator and was wondering if anyone has seen one like it or how to mount it as any clamping force on the stem housing locks it solid .

Ian

[I.M. OUTAHEREParticipant @i-m-outahere]

Anyone seen this model before and how do i mount it ?

[Michael GilliganParticipant @michaelgilligan61133]

Sorry, Ian … I don't think I have ever seen that style of back before.

Unless the indicator is a 'vintage' Made in England job … are you aware that all the better Mercer DTIs were badge-engineered Compac ones ?

It may be worth browsing the Long Island Indicator site for information.

http://www.longislandindicator.com/p41.html

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

< double post, deleted >

Edited By Michael Gilligan on 08/08/2016 08:11:46

[Ian PParticipant @ianp]

I have an identical indicator (apart from the resolution) and have no problems when clamping on the plunger outer sleeve.

The fit of the plunger in its bore has virtually no clearance so any appreciable force may distort it enough to jam the plunger. If your clamp has reamed close fitting bore then very little pressure is needed to hold the indicator.

Out of interest what is the resolution of the one in your picture? (the decimal point is hidden by the pointer.

Ian P

[AjohnwParticipant @ajohnw51620]

I've seen them before. They are nice to use on things like a lathe rather than a finger type.

I think you will find that what looks to be a square bar is an add on from how they usually are and that is where it would normally be clamped. Looks like it's intended to be held by the square bar. Maybe it has a slight dovetail ?

DTI's are used in test jigs at times so there can be all sorts of variations on how they are held in place.

John

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[Speedy Builder5Participant @speedybuilder5]

The DTI clamp on the right of the photo could work ?
BobH

[I.M. OUTAHEREParticipant @i-m-outahere]

Hi,

Thanks for all the replies .

Michael, the long island site was my first port of call unfortunately no luck there only the info about compac making them . Thanks for placing a link up there as some one may ead this in the futue and it will lead them to the best place to find anything out about measuring equipment .

Ian , i only tried it in my cheap indicator stand which probably had the mounting hole produced in a punching machine , the clamp is not vey wide so i will make a custom unit and see if it helps .

Pretty sure .002 mm but will check when i get home .

John , the back plate is one piece the rectangular lug houses a lever arm that transfers the movement from the stem to the rack .

As far as i can see it is unused but a little sticky from sitting for so long , the internals are mint and it is fully jewelled .

once again thanks for the replies !

Ian

[duncan webster 1Participant @duncanwebster1]

I used to have one like that, then I read an appeal from the people building a replica of Turing's bombe to borrow one. Being a generous soull I offered to lend them mine. That's the last I ever saw of it. Not that it was all that useful to me anyway.

Edited By duncan webster on 08/08/2016 18:36:33

[AjohnwParticipant @ajohnw51620]

The ones I have seen have been like this Ian. Including a longer larger diameter for mounting them. You may find yours has a hole for something like Mit's holding bare?

I've looked around for a small one of these with 0.0005" or better graduations several times.

John

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[Paul LousickParticipant @paullousick59116]

I have an old imperial Mercer indicator. 0.001" x 1/2" stroke.

The chrome plated cylinder at the top is only a push-on cover over the shaft and is not suitable for mounting. This one has a standard mounting lug at the back with a hole for bolting to a stand. Clamping to the guide at the top is probably restricting the movement of the plunger.

[Ian PParticipant @ianp]

Ian (XD35)

Having just looked at mine again I am sure the resolution of yours is 0.002mm/div (mine is 0.0001"/div).

I thought the marking on the dial in your picture might be 0.02mm

Mounting the DTI by gripping the stem seems to be the only method for this indicator so its not very versatile.

I'm not sure I agree with John about being nice to use on the lathe, I've tried with mine but its only any use if its used some way out from the chuck.

Ian P

[AjohnwParticipant @ajohnw51620]

I wonder who has the most DTI's kicking around ? I just counted 9 bought over many years. Initially I bought one off ebay used. Rather short stroke and 0.001" graduations. My brother spotted 2 in a scrap bin at work. Both read to 0.0001" and one has a very very long stroke. It had been used in a flip gauge so had slight play in the spindle in one direction so needed a bit of care in use. Then some one on here sold me a NOS 0.0001" Baty. That's on my magnetic stand now. I also have a hefty DTI stand which is used now and again. I bought a few for that and eventually happened on a 0.0001" John Bull. Probably ex inspection as it's perfect. Both have 1/2" strokes which I find to be ok.

I do have a finger type but don't like using it so have another 2 smaller dial types. One day they may finish up in a toolpost mount. Mainly for use on small machines – when I have one up and running. Really one such as the drawing of the Mitu… type I posted would be ideal for that as they don't take up much space. However every now and again I do centre stuff to no wobble on a 0.0001" reading gauge. Digital would help but I'd expect to find that it would need a new battery when I could do without that happening.

All makes me wonder if the best option when starting out is to just buy a brand new decent quality one. Might work out cheaper in the end. Just make sure it's the right one.

John

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[HopperParticipant @hopper]

Posted by XD 351 on 08/08/2016 18:03:43:…

…Ian , i only tried it in my cheap indicator stand which probably had the mounting hole produced in a punching machine , the clamp is not vey wide so i will make a custom unit and see if it helps .

….

As far as i can see it is unused but a little sticky from sitting for so long , the internals are mint and it is fully jewelled .

…

Ian

Clamping by the stem is common enough practice but as suggested above the clamp needs to be something like a square bar with a reamed hole in it that the stem just slides into, A slot and a pinch screw will provide the light clamping pressure you need. I think the cheap magnetic stand types made from two pieces with holes through them will put a bending force on the stem rather than an all round squeeze and this is probably what is binding up your plunger.

If it is sticky from sitting around, don't succumb to the temptation to oil it or clean it with solvents inside etc. Mitutoyo service sheet recommends only to lubricate the plunger where it sticks out of the stem, using a couple drops of petrol. I have found this to be good advice a number of times on old gauges I have scrounged up.

[Rik ShawParticipant @rikshaw]

Ian – Depending on the clock, some will function OK gripped by the plunger sleeve and some will not. Anyway, it should not be to much trouble to modify the back to suit your needs.

“I wonder who has the most DTI's kicking around ?”

 

I’ve just counted up – I have sixteen of various makes. The best plunger type I have is a .0001” Henri Hauser. I used one exactly the same many years ago on a Hauser jig grinder. The two I use most though are a Verdict ‘thou finger clock on a stand for clocking up in the lathe and a large 3” diameter half ‘thou Mercer plunger type on a diy comparator stand which lives on my granite surface plate next to the box of slips – a very handy combination and constantly in use.

 

On the subject of finger clocks a friend of mine was complaining recently of having difficulties in setting up a job because his Vedict would only read one way – I showed him how to move the little reversing lever on the side of the body to get the action to move the opposite way. He’d no idea what it was for but he’s ever so pleased now.

 

Rik

Edited By Rik Shaw on 09/08/2016 14:12:43

[AjohnwParticipant @ajohnw51620]

I'm not keen on finger types because of the travel even with the longer less sensitive fitting on it. I use a DTI to measure the run out and adjust accordingly and find that quicker.

John

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[Ian S CParticipant @iansc]

I'v got an old Starret, it's just a bit over 1" diameter. It doesn't get much use, but it was being thrown out so I took it home. Ian S C

Edited By Ian S C on 10/08/2016 13:32:29

[AjohnwParticipant @ajohnw51620]

I generally use this

It's fine on a Boxford as plenty of cross slide. It was a joke on a Peatol and too much on a Hobbtmat really as well. It would probably be awkward on a mini lathe.

It has 1/2" travel which I find is plenty. Not sure about the finger type but think it's under 1mm with the standard finger on it and maybe a bit over with the longer one.

John

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[I.M. OUTAHEREParticipant @i-m-outahere]

 

Hi everyone,

Yes it is 0.002 mm resolution .

I plan on using it as a TDC finder on my model engines so i will have to make a custom mount .

Ian that old #196 starret back plunge are useful for tramming mill tables as you can always see the dial face , they use a spiral staff to give movement to the needle and i have no idea how they get a spiral accurate enough to give a 0.001" resolution but I they do !

Off the top of my head i counted 13 indicators in my kit , a couple of 2" travel units 1 cheapie and 1 mitutoyo , 4 Dti in starrett , mx ( chinese ), tesa and spi (rebadged compac). Dial gauges range from cheap units i keep on cheap stands for general workshop use as I don't care they get broken through to starrett , compac and now a mercer.

For my mini lathe and little taig i use a Starrett last word as it is nice and small which is on a little tiny cheap mag stand that after a bit of a tuneup works ok .

I think that my collecting of indicators gauges is rapidly becoming a bigger sickness than my collecting of machinery ! Worst of all when i ran out of room i had to stop buying lathes and mills but indicators are small so i can always find somewhere to hide another one !

I'm thinking of getting the mercer serviced by someone who does this for a living as my big sauusage fingers are not suited to playing with little screws and gears !

Hopper ,

There are a few recommendations i have seen -petrol is one another was shellite or white spirit , apparently they leave a minute film behind which is all that is needed and the toolmaker i used to work for said the same as any oil traps dust and eventually dries up .

I have also been told to use watch oil on the bearings and gears but my tesa dti says not to oil anything at all so iguess each manufacturer is different .

I have been hunting around for a noga stand but to buy new here is so damned expensive !

Once again thank you all for you replies and ideas !

Ian

Edited By XD 351 on 10/08/2016 21:14:06

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