edge finder sensitivity

=========== Very informative thread with may good posts.

It appears that the edge finder (and wiggler/stick-pin) were developed as a work-around for spindle and tool-holder concentricity problems, particularly as these were used under power.

Does anyone know the history of the edge finder such as when it was developed, who developed it, etc.

Is the Schmidt/Flexbar the best of the manual edge finders are there even more expensive [manual/conventional] ones?

The pictures are impressive as are the prices. How many people are using Schmidt and Flexbar products?

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What's the groups opinion on the other items such as their

285$ surface gauge or their 995$ squareness gauge?
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how about that 6 jaw chuck for only 6,750$
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the square tech 90 degree indexer for only 17,250$!
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Flexbar edge finders and other goodies
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tried their centering microscope? (only 498$)
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Also what is the groups experience with sine bars, both magnetic [short generally 2 - 2_1/2 inches] and the full size 5/6/10 inch sine bars?

Unka' George [George McDuffee]

------------------------------------------- He that will not apply new remedies, must expect new evils: for Time is the greatest innovator: and if Time, of course, alter things to the worse, and wisdom and counsel shall not alter them to the better, what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman. Essays, "Of Innovations" (1597-1625).

Reply to
F. George McDuffee
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Bob, Is the Fadal a box way machine? Haas is linear? that's good to know if the Fadal is in fact a box way machine.

I looked on the Herman Schmidt site and the edge finders are $45. I might give one a try. The last Starrett I bought was mid $20. I wonder if Herman Schmidts do any better after you start the spindle at max RPM? I would hope that besides lapped surfaces that the grinding surface finish would be better than the Starrett. Knowing Herman Schmidt stuff I'm sure it's top notch.

I've got the feeling that Starrett like a lot of American companies have things like edge finders built overseas.

Reply to
GarlicDude

I have aSstarrett, and after a couple of years sitting around not getting used much, the factory lube got pretty gummy. I gave it a good cleaning & re-oiled it with a light oil, and it works MUCH better now.

Doug White

Reply to
Doug White

Carl:

All the edge finders I've ever measured were the exact size (the .200 size ones WERE .2000, the .500 size ones WERE .5000).

If you have to go .0004 FARTHER than half the tip diameter to have it "kick-out", then I think you'd want the tip diameter to be .0008 oversize for compensation purposes. If I've got it backwards, I'm sure someone will surely tell me. LOL

Reply to
BottleBob

Steve:

For Fadals, it depends on the model. We've got three box way Fadals and one linear way Fadal.

Or come DOWN hard ON your part. LOL

Ahhhh but how can you be 100% certain that ol' Herman isn't outsourcing some of machining/grinding/lapping, and is just assembling them in the U.S., eh?

Reply to
BottleBob

Anyone needing precision in the context implied is obviously setting up somethng to be recut after having screwed the thing up, or at least after it's finished. When, Bob, was the last time you guys intentionally ordered stock ground to finish size for a job? I'll save you the trouble and tell you. Never.

Neither does any other sane person. Not for production on a short run basis and I'll be I could spend a month in Valencia and never see such a thing.

Intresting thread but when you get to process planning you'll be into something that's useful.

Reply to
John R. Carroll

John:

Not necessarily. A job with multiple operations will often have to located accurately off a previously machined surface or feature.

You're right, not often. But I wouldn't say never.

Come on over, I've been edge finding a part in different setups with multiple operations all week.

Process planning? You mean planning the order of operations in your before you begin machining? Isn't that an integral part of the job description of being a CNC programmer, eh? LOL

Reply to
BottleBob

Planned in advance you might be able to use features as tooling holes. You know, where you drill, bore and ream a .2505 dowel pin hole where there is a 1/4-28 tapped hole. LOL

Ok, very infrequently.

I, yes me - moi, am taking a week off. I'm in San Diego with my mother. She's old and having a little trouble getting settled with health insurance and prescription drug coverage. GM is dumping their pensioners.

I decided that it was a better use of my time than telling Kris, our favorite welder, that he needs either a second debilitating sand buggy accident or another line of work. BTW, that's a lot calmer statement than I would have made Friday so I guess the time off was a good choice.

See me next week if you are around. We'll "edge find" our way around a couple plates of Vince's lasagna. Plus or minus a fork full.

Maybe, but what I meant was looking a job over and planning it so you didn't find yourself trying to figure out where the thing was as you went along with indicators or edge finders. That ought to come in concert with whoever quoted the work in the first place.

The real key to success in your environment is planning the last operation. That and the fixturing to make it happen accurately and repeatably.

Reply to
John R. Carroll

BottleBob, my "BB" commentary was addressed to "Bipolar Bear" @ 12:59, NOT to you.

I had a look at your website and concluded that you do not require any opinion from me on how to do things accurately and precisely :-)).

Bipolar made some commentary on spindle squareness or such, and I thought it worthwhile to elaborate a little on other unmentioned requirements for accurate edge finding.

Wolfgang

Reply to
wfhabicher

Jon A.:

Thanks for that precis on the MOORE tome. I must beg, borrow, buy? a copy. If anybody has a line on one, especially at reasonable price... Thanks, and please let me know.

Wolfgang

Reply to
wfhabicher

Wolfgang:

I'm sorry, everybody calls me BB so I never even considered that you might be referring to someone else. My bad.

We're ALL constantly learning. When we stop, we're ready for that proverbial dirt nap.

I believe I saw that. Something about a quill. My opinions/comments are usually from a CNC perspective. Although I was a manual machinist for many years prior to that. And still do some fixture & second op manual machining.

Reply to
BottleBob

The Fadal you ran the test on was a ??

Old Herman would do that would he? Which brings up the question, is Herman still alive and running things? Anyone know? I went to a mid 80s Westec with my boss at the time who was German. He stuck up a conversation with Herman, we went few drinks with him and he and my supervisor chattered in German for quite a while. At that time his product line was very small. Vises, squaring fixtures, and whirly-gigs were about it as I recall. Now his product line is huge.

Best, Steve

Reply to
Garlicdude

Steve:

The test was run on a box way 3016 Fadal.

It's a simple test that anyone can do in any milling machine. I'd be interested in the results others achieve. (I don't care much about the "chair" results, just the comparison between edge finders and direct indicating).

Perhaps not. Especially given the prices on some of his products.

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Reply to
BottleBob

Hey Eric,

OK. Thank you. I'll get one and give it a try.

Brian Lawson

Reply to
Brian Lawson

[ ... ]

It is where the lapped finish joint between the fixed and moving halves occurs -- and with the larger radius it probably has a greater contact surface area, so it is able to slide more freely when the forces are right for the kick. I would like to try one, but I would not like to pay for one at present. :-)

Enjoy, DoN.

Reply to
DoN. Nichols

Why trust your feelings when it's so easy to pick up a catalog or go to their website and find out for sure?

It's made here, by the way. Have no idea about the Schmidt.

John Martin

Reply to
John Martin

Mr. Martin:

Perhaps all of Starrett's products are made 100% in the U.S. Or maybe only 90% (or some other percentage), of the work is done in the U.S. Color me cynical, but I'm not 100% convinced that a product is completely made in the USA just because of some advertising on a corporate website says it is.

Reply to
BottleBob

Or is the "Made in USA" label the only part made in USA? Gerry :-)} London, Canada

Reply to
Gerald Miller

Hell..even Ive got a Cadillac gage. 24" range. Stands up nicely on the 34 x 45" surface place (Microflat)

In the home shop....

Been more than one engine blueprinted on that rig

Shrug

Gunner

"Confiscating wealth from those who have earned it, inherited it, or got lucky is never going to help 'the poor.' Poverty isn't caused by some people having more money than others, just as obesity isn't caused by McDonald's serving super-sized orders of French fries Poverty, like obesity, is caused by the life choices that dictate results." - John Tucci,

Reply to
Gunner Asch

============= Some URLs of interest about edge finders.

First US patent appears to be in 1934

Some edge finder URLS of interest

Cole et al in U.S. Pat. No. 1,984,864

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Patent number: 2451904 Filing date: Jul 15, 1946 Issue date: Oct 1940
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Moore chair Item # 3070-A Edgefinder, Inch $4,110.00

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Unka' George [George McDuffee]

------------------------------------------- He that will not apply new remedies, must expect new evils: for Time is the greatest innovator: and if Time, of course, alter things to the worse, and wisdom and counsel shall not alter them to the better, what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman. Essays, "Of Innovations" (1597-1625).

Reply to
F. George McDuffee

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