DTI advice

[Molochnik]

I did a search and couldn't come up w/ anything.........I'm looking at purchasing a test indicator, and am a bit confused on what may or may not be important.

The ones I have used so far (Starrett) simply have a shank that pivots on a trunnion for mounting. I see a lot of them now that feature a dovetail arrangement, and some are pictured w/ no mounting provisions at all.

I understand the "get what you pay for" tenet in selecting one over another, but I'd appreciate some opinions on the more ubiquitous ones out there i.e. Brown & Sharpe, Fowler, SPI, Starrett, and if the simple shank/trunnion arrangement is adequate or if dovetails are the way to go.

Thanks in advance

[christinandavid]

Swivelly shank is invaluable when using in a chuck in machine spindle.

I use Verdict T8

DP

[Molochnik]

Thanks for the advice. I would've thought more folks have opinions on these things.

I'm currently leaning toward an Interapid (w/ swivelly shank). As I weave my way through a google search, it seems I'm finding more good things than bad things said about them.

It's just tough to be sure when there are units ranging from $50-$250+ out there when one reaches the point of diminishing return on investment.

[christinandavid]

Go for design/accuracy range depending on the work. I never used a plunge type in my last job, now I use them more readily than lever type.

Go for more pricey/rigid arrangement if you are using solely for post-machining inspection. Don't go for too expensive if you intend to use for on-machine set-ups, especially CNC. You only have to push the wrong button and your DTI is history. I have wasted a few T8's this way, but was lucky that it was a popular model and could always get it rebuilt by inspection department - my DTI is now a 'frankenstein' made up of about half a dozen different units...

Go for a skinny/lightweight model for on-machine use - only last week I had to re-bore a component that had sprung after finishing and my trusty battered old T8 was the only thing that I could use to clock the top and bottom of the bores. It was good to find that it was just as accurate on a horizontal as a vertical!

Recommend you do the stylii up hand tight. You'll find out why when you snap one

DP

[Molochnik]

Hey thanks for the empirical advice. I've all but pulled the trigger on an Interapid 312b-2, but it sounds like I may be able to get away w/ something "cheaper". I was also planning on buying a real "lower end" model too that comes w/ a stand rig, since the Interapid doesn't come w/ anything. I think it's a good idea to have a real good one anyway, so I'll probably just end up getting it.

I don't have a CNC, just a manual mill w/ some powerfeeds. I don't think there's much call for post-machining inspection as the vast majority of stuff I make or modify is simply to support the maintenance I do; most of it is "inspected" before it leaves the vise or fixtures.

The primary uses will be set-up and squaring.

I did a search in the general metalworking forum, and it seems that Interapids, B&S, and some names I've never seen (like yours) in the catalogs I use are the favorites..........B&S having the largest following, from I've read so far. I have also read in more than one place that B&S actually makes the Interapid. I thought the measurement forum would have more discussion on preferences; go figure.............lots of data to be found just the same.

Thanks again for the help!

[ImanCarrot]

I've used Mahr Gauges for years without a complaint, also Federal Gauges for precision work, I think they might be the same company now (not sure) but a google search for "Mahr Gauge" or "Federal Gauge" should get you there (I have no interest the companies other than being a satisfied customer).

[Molochnik]

Wow, the Mahr 801H looks like it would be pretty sweet for squaring the quill. That's the first one I've seen like that, but I'm admittedly ignorant of all but the most common models.

Thanks. I may have to find a dealer and see what one of those costs.

[Molochnik]

$136 through CDI, hmmm

[CarbideBob]

Buy an Interapid and never look back. Nothing will last longer. (They are non-magnetic too which helps on SGs with magnetic chucks.)
Brown & Sharpes are my second choice but they only live about 6-8 years with the abuse I give them.
Mits are good but we throw them out after about 2 years of use.
I only buy .0001 and 50 millionths models but I'm kind of fussy.

Manual mill? also get an Indicol mount. A "must have". Buy the real thing, not a copy. You won't be sorry.

Just my 2 cents worth from my few years experience.

Bob

[Molochnik]

Thanks..........the Interapid is actually already on its way. I'll have to look up the Indicol mount, not familiar w/ those.