Back plunger indicators - does anyone use them?

I have just aquired a rather nice Starrett #650 'back plunger' type indicator. I've never used one of these before as I have always used the more conventional dial indicators and lever type dial test indicators. The back plunger type seem more common in America maybe.

Any tips or comments on their use? Any advantages over the more usual types for general workshop indicating?

Very occasionally, I use one.

They can save a lot of craning of the neck in some situations.

Howard

Can be handy for jobs like mill head tramming as the face is always in view.

Mike

I worked for Baty's for a couple of years in the '80s, and as far as I know there were none in their very extensive and practically unplannable dial gauge range then. I'd guess they'd probably have to use a helical worm rather than a rack and pinion to drive the hand in a different plane, and that might be more expensive to make and harder to maintain.

As Howard says the angle of view can be better than a conventional plunger type in many machine set up applications. Especially if you have the full set of Starrett (or other make) accessories. Ultimately the standard plunger style indicator is intended for quality control purposes when mounted in a stand rather than machine set up. Which doesn't stop it doing a perfectly good job when needed but I suspect folk who have properly learned to exploit the back plunger type may get along a little better.

Hafta say I grabbed my Starrett Last Word set with all the bits very cheaply (probably due to it being stuffd into a three layer pencil case rather than a proper box) maybe 30 years ago thinking "This will be very useful.". Yup so useful that I've literally never used it! That said my 5 standard stye ones average around 2 or 3 outings a year at most. The lever types and Blake Co-Ax knock off do all the heavy lifting.

One thing in the set that really out to be useful is the "extender seesaw" thingy which can be poked something approaching 2 1/2 inches down a bore.

Clive

Edited By Clive Foster on 20/01/2020 21:56:05

Edited By Clive Foster on 20/01/2020 21:56:22

I wouldn't mind one in my workshop.

I've got a nice Mercer which is only really used for tramming the mill tables, easy to see the dial face. Other than that particular job I can't see any advantage of using a back plunger dial gauge rather than the usual type or Verdict lever type.

Ian

Works well for tramming in a vise also. use one all the time.

I nearly bought one at Christmas (Amazon had some seriously silly price reductions of 75% or more) thinking the "see-saw" deep hole attachment looked handy but in the end went for a vertical dial DTI which, like the back plunger indicator, can also be read in any position on the mill. I have to say though, US made Starrett kit always looks and feels lovely, especially in the padded jewellery boxes.

Brian G

50 odd years machining & I can't recall ever having used one.

Tony

I do as well and I know now what it's called.

John

+1.

Use mine for tramming the mill and shaper vises in.

Dial face is staring straight at me.

I use these all the time, never owned a lever-type. One is a Mercer in a fitted case with all the trimmings, and I have a couple of others from car-boot sales, permanently fitted to various bits of equipment.