Mercer Dial Indicator

I pick up this at a sale and was wondering if anybody knew how it worked

It's a Mercer model 107A dial indictor set

Looks like a comparator to me. You use the clamp on the edge of a surface plate and the clock on the clamp. Components are then slid under the stylus to compare. I think ?

Last time I used one of these set ups was for reverse alignment readings on Turbine - gearbox - pump etc. alignment; the clamp was fixed to the relevant coupling flange, the dial indicator was placed either on the rim or face of the opposite coupling .. depending whether you were taking rim or face reading.. a sweep taken from top to bottom .. resultant reading divided by 2 gave you offset from centre line + or - .xxxx" reverse set up & repeat you then calculated, shimmed, or moved driver / driven appropriately.. horizontally or vertically, allowing for thermal expansion etc. to attain desired alignment.

The cross bar was used in the same manner but on an internal bore diameter.. etc. etc. Have also used it as a comparator on surface plate when I was in toolroom as John mentioned, also used it to check for any shaft run out /bend when shaft set up on vee blocks .. so multiple uses, can be adapted to suit work.

p.s. You shouldn't clamp anything to a surface plate, CI or granite, use the long bar with the vertical post or magnetic stand (& we've all done it   

Cheers

George.

Edited By mechman48 on 06/02/2014 09:40:29

It looks similar to a beat up one that I got some years ago, if it is the contact is a rod sticking out the back of the instrument. Just been out to the workshop, and bought it in, and find that my one has "The L.S.Starrett Co. Athol Mass U.S.A.. It's 1 3/8" dia, and reads .001". Sorry getting OT. Ian S C

Hi
You can use one like I do on my mill drill for accurate depth setting in Z

Picture shows the tilting "see-saw" extension device from my Starrett Last Word accessory set used with a standard plunger indicator to pick up an internal taper whent setting the taper turning attachment on my Smart & Brown 1024 VSL lathe. Your Mercer set includes an essentially identical device.

Normally the mounting spigot on the indicator is fitted into the empty hole in the pivoting lever mount with the indicator arranged so the free end of the see-saw pushes the indicator plunger. I could have set things up using the Starrett indicator but it would have obscured the view of the taper somewhat and the spare length of mounting rod projecting through the fixing hole would have reduced the amount of gauging travel. Important in this case because there was a parallel bore around 1/2 inch long before the taper began. The Smart & Brown has plenty of real estate on its massive cross slide to hang things off an old style Eclipse magnetic base as shown which facilitated switching to a tenths thou indicator for final setting up. More rods and clamps involved tho' so much more fiddly.

The rectangular bar and rod are provided to facilitate mounting in a toolpost but can be creatively used in many other ways.

Clive

Clive,

That's a very useful photo of the set-up

... Nicely done, Sir.

MichaelG.

You have a useful piece of kit there.

The black rectangular bar, (with the 1/4 or 5/16" spindle attached) can be fitted onto a Height Gauge, for use on a Surface Plate or table. It can also be clamped (carefully, and preferably protected on both dises) in a toolpost on the lathe.

The clamp will allow it to be fitted in a variety of places, but as has already been said, not to Surface plate or table.

The DTI can be used as a normal Plunger Clock, or as others have said, to check run out, (or position) of bores, using the pivoting accessory.

Quite versatile, you will find it very useful as time goes on.

Well Done for a good find!

Howard

Thanks for all the feedback. I will be trying it out this weekend. I also have a normal clock on magnetic base. I am sure I will be able to align anything now. O I forgot My favorite the edge finder.

Here is a very interesting piece I found on how to make your own extension for your dial indicator

http://www.homemadetools.net/dial-indicator-holder-5

Thanks for the link, Kenneth

That's quite tidy, and [re: the ongoing discussion about short articles in MEW] it nicely demonstrates what can be presented in half a page.

MichaelG.