Test Indicator Opinions
I have a Starrett last word test indicator that I purchased several years ago at a flea market for not too much money. It languished in my box until recently when I wanted to use it. Upon closer inspection I found that the crystal falls out easily and the indicator itself is slightly sticky. The bezel that rotates and holds the crystal is OK but rotates with difficulty and the face of the dial is warped if the bezel is removed.
I can have this indicator repaired to like new condition by Long Island Indicator for about $70 or I can purchase a new indicator. Some older posts here recommend Interapid highly but I don't know the price. Some older posts also speak about the Last Word indicators being "sticky" as one of their quirks
I can purchase, new from Enco, a Fowler for about $55, or the Enco brand for $37. Other suppliers have similar prices for their low end indicators. Money is tighter these days however I spend for the long term and like to purchase the best I can afford. What would you do, repair the Starrett or purchase a new indicator, and why and what indicator do you recommend?
Thanks for your responses in advance.
Some folks like the Last word, but most (me included) prefer the style like Interapid or Brown & Sharpe.
Long Island has a page comparing test indicators that's a very good read:
I have a couple or so Last Word sets that work fine, but over the past decade or two I think I've use one of them once or twice and I use my nice old BestTest indicator pretty much every day.
Long story short, if you were me you'd not spend any money at all on the Last Word since it may sit in the drawer forever and instead spend that money toward one you'll prefer to begin with.
If you have the money, Interapid is a fine device. For less money the BestTest indicators are very durable too but similar in configuration and everything else.
BTW, it's important you get the scale and range you actually need and don't go overboard on the resolution. I find that mine is about perfect for general machining and it's got 1/2 thou graduations on the dial and approx. +/- .030" of travel range. Only on occasion do I need and use my .0001" test indicator on the seldom-needed high-tolerance job - the movement is too sensitive to read easily and the short range is cumbersome I think. I would probably be just about as happy with a .001" test indicator but the half-thou one came to me like it is and it works nicely for me.
I have a lot of indicators of various kinds. My favorite one for the inspection room is an Interapid. They are about $220 now. My next favorite one is a Fowler X Test, a copy of the Interapid. They are $80 in the latest Enco catalog. I have 2 of those for the shop, one I use and one if something happens to that one. They are extended range with .060 movement. Very smooth and repeatable. The marks are in .0005 increments, it has another small dial to keep track of turns.
Last edited by Toolguy; 11-14-2011 at 07:24 PM.
Interapid, Compac, B & S, anything but a last word.
I own an Interapid DTI and I've used B&S BestTest DTI's quite a bit, too. They are both good but if money is tight, I suggest waiting until a B&S BestTest goes on sale or until you get a good promotion from Enco. (BestTest indicators tend to be just a shade less expensive than the Interapid and they are in the same class of instrument). Since they are small, a 15% off discount may save you more money than free shipping. With the Holdidays right around the corner, expect some promotions from Enco.
One thing to note is that the Interapid DTI's are "backwards". It's a little confusing at first because my intuition built from using other DTI's tells me that when I deflect the stylus one direction, the needle should move clockwise but the Interapid moves counterclockwise and vice-versa. Not a big deal, just an interesting tid-bit.
Edit: Toolguy brings up another point. Depending on the resolution you want, you may opt for a DTI with greater range.
Last edited by Fasttrack; 11-14-2011 at 07:02 PM.
I like my B&S. Plenty of nice used DTI's on Ebay for embarrassingly cheap.
.001 is OK with me, I have no problem with splitting a division to get to a half if necessary. seldom in my world do I need better. I have a Swiss .0005 in, can't recall the last time I used it. Ought to put on Ebay I guess. Bob.
I have two DTI's, Mitutoyo 513-402 with a range of 0-15-0 an a Interapid 312 B-1. I prefer the Interapid, but it's twice the cost of the Mitutoyo.
let me say that first i'm very new to this field, and i hold no illusions about my capabilities so far. because of that, and the fact that this is currently a hobby, i can't justify the cost of most of the big-name precision accessories. for example, i bought my 4" mill vise as an import brand from enco because a kurt vise cost more than i paid for my mill/drill and all the accessories that i got with it.
when i learned the use for a test indicator i also decided to go with a cheap one figuring that it would be more than adequate for my needs. i paid $22 including shipping for a new one on ebay. i got it, and it works fine, but the quality is certainly not there. the indicator point is actually not even close to parallel with the body of the indicator. it's not bent or assembled wrong, but the piece the point screws into isn't machined true. as i said, it does work and return to zero fine, but it just doesn't give me that warm feeling. it's also a little ratchety (is that a word?) and noisy in the movement.
i kept looking for something a little better, since it is something that i will be using a lot. i ended up finding and buying a fowler x-test for $39 including shipping on ebay. it was basically second hand but never used. i didn't get a case or the two adapters that usually come with it, but the indicator was just like new. the fit and finish on the fowler was much better, and the movement is actually much smoother and quieter. sometime i need to replace my old dial calipers and get a drop indicator, and i'm going to go with fowler on them. it seems like a good compromise between price and quality.
I have a couple Fowler items (cheap bore measuring thing and a 3-4 mic) and seen a bunch of other Fowler stuff. Some of it isn't bad. My 3-4 mic is smooth and accurate along it's whole range. But I still just use it at home since I have a Mitutoyo set at work. Still, it's fine.
Originally Posted by lost_cause
However, some other Fowler stuff I've seen is pretty awful. So what I would suggest is not to dismiss it off hand, but if you can, handle the one you're buying in person before you spend any good money on them.
Fowler is an Asian import and the items originate from several separate locations on that continent. Standard caveats apply.
I remember now one thing I often say to newcomer machinists:
On a DTI, it takes a little experience I think before you acquire the attention it takes to use the thing so you don't accident it into oblivion. The common example mistake is to absent-mindedly turn on a spindle and whip it around at 1200 rpm before it gets thrown to the concrete floor. So anyways, it might not be a bad idea to get a cheapie to fiddle with for a while before you invest in a nice one. I suggest this for two reasons. 1) Use of a DTI is used almost entirely for comparative measurement rather than quantitative measurement, so accuracy isn't all that important as long as it's action is smooth. 2) Even a good DTI is somewhat inherently fragile, so it takes a far less severe accident to dork it bad enough to cause problems.
There are limits of course and I've handled (briefly) a few DTIs which I just wouldn't try using. But like I mentioned, as long as the mechanism is smooth, you should accomplish what you want to with it.