I've never used a bore gage (dial bore gage, whatever). I've only used
inside mics (of the tubular variety) and telescopic gages. Are bore gages
sufficiently snazzy to make them worth the relatively upper-crusty price
tag? A set of intramics is absolutely out of the question. 8-)

--
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Mike Graham | Metalworker, rustic, part-time zealot.
| Sporadically WOEful.
http://www.metalmangler.com| First run on low-carb: 320lbs to 210lbs.
Restarted June 01/2003 - 245/229/not sure.

DENIQUE DIAETAM EFFICACEM INVENI

On Sat, 12 Jul 2003 18:36:25 -0400, Mike Graham
wrote:

I've never used a bore gage (dial bore gage, whatever). I've only used
inside mics (of the tubular variety) and telescopic gages. Are bore gages
sufficiently snazzy to make them worth the relatively upper-crusty price
tag? A set of intramics is absolutely out of the question. 8-)


I got a few bore guages at an auction. They are nice, accurate and
fast. The set that uses three points to measure diameter are cool.
But, not worth the price if you had to buy new unless you were running
production on the same part all day long. Or, grinding a bore to a
couple tenths tolerance.

I don't like telescoping guages - too putsy and easy to make an error
of a thou. Of course, inside mikes don't go below 1", and you get a
lot of need to measure in this range. You didn't mention gage pins, I
like them for under 1" bores.

Karl

In article , Karl Townsend wrote:

I got a few bore guages at an auction. They are nice, accurate and
fast. The set that uses three points to measure diameter are cool.

I'm looking at things like the Mitutoyo series 526. They *seem* to be
basically like telescopic guages, but with a dial. The set I'm looking at
goes from 1.4" to 6". I know that Mitutoyo makes them to work in holes as
small as .240" diameter, but this one won't go anywhere near that small.

I don't like telescoping guages - too putsy and easy to make an error
of a thou.

I've had good luck with them, but certainly they are not without their
flaws. At the very least it sucks to have to keep measuring them - the bore
gages should be a lot faster, if nothing else.

Of course, inside mikes don't go below 1",

I think 1.5" is the smallest I've seen.

lot of need to measure in this range. You didn't mention gage pins, I
like them for under 1" bores.

I use small-hole gages and telescopic gages pretty much exclusively at
this point, but I'm considering broadening my horizons. 8-)

--
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Mike Graham | Metalworker, rustic, part-time zealot.
|
http://www.metalmangler.com| Caledon, Ontario, Canada

Mike Graham wrote in message . ..
I've never used a bore gage (dial bore gage, whatever). I've only used
inside mics (of the tubular variety) and telescopic gages. Are bore gages
sufficiently snazzy to make them worth the relatively upper-crusty price
tag? A set of intramics is absolutely out of the question. 8-)

If you need the accuracy, they are great. We've got at least 30 Mohr
gage kits here at work. Our kits can cover everything from .128" all
the way up to .500". Kits consist of a digital head, various extension
pins and the necessary ball ends and check rings. Takes about 30
seconds to set one up. When you have to do hole diameter checks on
500-600 holes in a single installation, it makes for fast inspection.
Don't know what the kits cost, but I believe that you can start with
just the head and one size set up.

Craig C.

"Mike Graham" wrote in message
...
I've never used a bore gage (dial bore gage, whatever). I've only used
inside mics (of the tubular variety) and telescopic gages. Are bore gages
sufficiently snazzy to make them worth the relatively upper-crusty price
tag? A set of intramics is absolutely out of the question. 8-)



I don't think so!
My experience is the low to mid price bore gauges have poor repeatability,
and the higher quality ones are just too expensive to justify!
I tried a couple of dial bore gauges out a few years back. I ended up
returning them and went back to telescoping gauges.
Greg

Subject: Bore gages
From: Mike Graham
Date: 12/07/03 23:36 GMT Daylight Time
Message-id:

I've never used a bore gage (dial bore gage, whatever).

Good god man, you've never lived.

I've only used
inside mics (of the tubular variety) and telescopic gages. Are bore gages
sufficiently snazzy to make them worth the relatively upper-crusty price
tag? A set of intramics is absolutely out of the question. 8-)

Bore gauges are a must have if you do a lot of accurate i/d work. I have three
sets. The main one for engine bores is a Mercer 2" - 6" which reads to a tenth
of a thou. It does that fairly repeatably too. It's actually fairly scary
putting it down most production bored and honed blocks and watching the needle
move so far round the dial with taper and ovality. Most engine builders use a 1
thou gauge which makes a badly bored block look a lot less wrong. That gauge
made me get my own boring and honing perfect though because it exaggerates
small variations so much you feel like you've cocked a job up if the gauge
moves at all.

The other two sets get used a lot less. One runs 0.75" to 2" and the other goes
down to 0.5". They are both pretty old sets and read to a thou. The Mercer
looked brand new and still does because I've taken care of it. I picked the lot
up several years ago for 200 quid at a metrology establishment with a 0-1" dial
gauge and a 3" to 4" Moore and Wright mike thrown in for free. I only went
there for the Mercer but he kept bringing out stuff I thought would "come in
handy sometime" and he made me an offer I couldn't refuse for the job lot
Those places often have good second hand stuff for sale which they've rebuilt
and calibrated. What my lot would cost new these days I shudder to think.

I only use the telescoping gauges for measuring valve seat insert bores in
cylinder heads when I'm fitting unleaded inserts or bigger inserts. With a
shallow hole bored down to a flat base there often isn't enough depth to get a
bore gauge in and still be able to rock the pins over centre. I hate using the
telescoping ones though. Slow and fiddly and you get a different measurement
every time you use them. A colleague reckons you'll always measure slightly big
with those and he tends to knock half a thou off whatever the micrometer says
when you measure the gauge. Especially in soft metals like ally where the ends
dig in a bit as you rock them over centre. One of these days I must have a play
with a through bore and see how a T gauge reads compared to the Mercer.

For through bores like engines and especially long bores the dial gauges are
the only way. You can take a reading in a couple of seconds and know it's
right. You can map out a bore from top to bottom measuring taper and ovality to
a tenth or so in no time. With T gauges it'd take forever and not be accurate
anyway.

The three pronged gauges are very expensive and supposedly very accurate but no
good for meauring ovality of course as you aren't just reading across a
diameter. I've never found the need for one. I couldn't manage at all without
the Mercer though.


Dave Baker - Puma Race Engines (www.pumaracing.co.uk)
You find somebody to love in this world you'd better hang on tooth and nail -
the wolf is always at the door. (Don Henley - In A New York Minute)

In article , Craig wrote:

If you need the accuracy, they are great. We've got at least 30 Mohr
gage kits here at work. Our kits can cover everything from .128" all
the way up to .500". Kits consist of a digital head, various extension
pins and the necessary ball ends and check rings.

Ah. There are two basic kinds of these things.. they really do mimic the
small hole gages (with the ball-end) or the telescopic gages. The ones that
you use are the small-hole-gage type. I'm looking for something to do up to
6" or larger bores. That would be a big ball. 8-)

Don't know what the kits cost, but I believe that you can start with
just the head and one size set up.

You normally buy the ones of that style sized for a particular range,
like 0.100" to 0.250", that kind of thing. There are a few sizes listed in
my catalogue, running up to about 1.5", where the telescopic-gage-type takes
over.

--
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Mike Graham | Metalworker, rustic, part-time zealot.
|
http://www.metalmangler.com| Caledon, Ontario, Canada

In article , Dave Baker wrote:

Good god man, you've never lived.

You're not the first to say that. 8-)

Bore gauges are a must have if you do a lot of accurate i/d work. I have three
sets. The main one for engine bores is a Mercer 2" - 6" which reads to a tenth
of a thou.
snip
The other two sets get used a lot less. One runs 0.75" to 2" and the other goes
down to 0.5". They are both pretty old sets and read to a thou.
snip
What my lot would cost new these days I shudder to think.

For the 2-6", in tenths, from Mitutoyo, brand new retail price down the
street is $408.50 Canadian. The .750-2" would be about $310 (no perfect
match in ranges; that's an average of the prices of two reasonable matches).
The last one would be around $380. No perfect match there, either. So
those three sets would run you around $1100 Canadian, which is still a fair
bit when converted to pound sterling.

when you measure the gauge. Especially in soft metals like ally where the ends
dig in a bit as you rock them over centre. One of these days I must have a play
with a through bore and see how a T gauge reads compared to the Mercer.

The sets at work have been through the wringer. Too many apprentices with
no brains using them, I guess. The ends are worn flat. Probably tightened
up too hard before rocking them.

For through bores like engines and especially long bores the dial gauges are
the only way.

I am usually dealing with short bores, but I'm still seriously considering
picking the set up.

--
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Mike Graham | Metalworker, rustic, part-time zealot.
|
http://www.metalmangler.com| Caledon, Ontario, Canada

In article , a
says...

Bore gauges are a must have if you do a lot of accurate i/d work. I have three
sets. The main one for engine bores is a Mercer 2" - 6" which reads to a tenth
of a thou. It does that fairly repeatably too.

I bought a couple of Federal dial bore gages at work
for some finicky bits. They are worth every penny.

Best is if you can set them with ring gages, I've
been making do with micrometers. Not right but
they still show variation at the 0.0001 level.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

Subject: Bore gages
From: jim rozen
Date: 13/07/03 04:40 GMT Daylight Time
Message-id:

In article ,

says...

Bore gauges are a must have if you do a lot of accurate i/d work. I have
three
sets. The main one for engine bores is a Mercer 2" - 6" which reads to a
tenth
of a thou. It does that fairly repeatably too.

I bought a couple of Federal dial bore gages at work
for some finicky bits. They are worth every penny.

Best is if you can set them with ring gages, I've
been making do with micrometers. Not right but
they still show variation at the 0.0001 level.

That's definitely the best way I agree, not that I have any and have to make do
with the mike for setting. It compensates for any error in how perfectly the
gauge lies across a true diameter of the bore it's measuring which is down to
the accuracy of the two contact feet on the measuring head. For engine work a
few tenths is neither here nor there really when most pistons have a tolerance
of -0/+0.001" on the bore size and plenty of production engines don't even get
within that 1 thou range.

For comparison work on bore taper and ovality, knowing the true size isn't so
important. For high precision engineering if you're trying to hit a tenth on
diameter I'm sure ring gauges play their part.


Dave Baker - Puma Race Engines (www.pumaracing.co.uk)
You find somebody to love in this world you'd better hang on tooth and nail -
the wolf is always at the door. (Don Henley - In A New York Minute)

Dave Baker wrote:

That's definitely the best way I agree, not that I have any and have to
make do with the mike for setting.

Just a warning for using the mike.
You will get to small readings (about 1..2/100 mm) if you don't put a
load on the mikes anvil (pressing slightly outwards; 10 N force is about
right to make the mike's ratchet work) when adjusting it. Don't forget
to lock the mike's anvil under load.

I once cross checked a inner mike, a ring gauge and a mike and always
got that error, so I doubted the ring gauge. But the ring gauge was
only 0.5/1000 mm below size (I took it for calibration). The error came
from the minor blacklash of the outer mike. Remember that mikes do have
a ratchet, some backlash and need a defined load to be accurate.

Jo blocks and a special fixture or ring gauges are the only reliable way
to set bore gauges. I do have only one ring gauge and use the mike.


Nick
--
Never use force, just go and get a bigger hammer.

Nick Mueller wrote:

Dave Baker wrote:

That's definitely the best way I agree, not that I have any and have to
make do with the mike for setting.

Just a warning for using the mike.
You will get to small readings (about 1..2/100 mm) if you don't put a
load on the mikes anvil (pressing slightly outwards; 10 N force is about
right to make the mike's ratchet work) when adjusting it. Don't forget
to lock the mike's anvil under load.

I once cross checked a inner mike, a ring gauge and a mike and always
got that error, so I doubted the ring gauge. But the ring gauge was
only 0.5/1000 mm below size (I took it for calibration). The error came
from the minor blacklash of the outer mike. Remember that mikes do have
a ratchet, some backlash and need a defined load to be accurate.

Jo blocks and a special fixture or ring gauges are the only reliable way
to set bore gauges. I do have only one ring gauge and use the mike.

Nick
--
Never use force, just go and get a bigger hammer.

I was going to mention Jo blocks also. I've got one of those cool racks to
stack & clamp them in. Can't justify buying ring gages, especially with the
Jo's already in hand. Have never bought a bore gage either. A few of us have
a borrow club sorta thing. If ya need it, and the other guy's got it, go get
it. Saves us some coin.

michael

Best is if you can set them with ring gages, I've
been making do with micrometers. Not right but
they still show variation at the 0.0001 level.


I made my own ring guages. Piece of cake, just a little lathe work.
After they are ground on the ID, you just need someone with a very
accurate tool to measure them. Then stamp this reading on your
homemade guage. In my case, I traded a favor with Joe Way (seen on
this NG)

Karl

In article , Lennie the Lurker wrote:

Depends. If you're doing production, they would be indispensable. If
you're doing one off in a tool room situation, maybe. For general
machining, probably not.

I can see how the 'dial' aspect of them would be very important when
looking for the condition of a bore... when looking for bulges, waisting,
out of round, etc. I'm primarily looking for a fast and accurate way to see
where I am in the boring process so that after I take my final 40 thou cut,
I'm where I want to be.

Federal, Starrett, Standard and Mitutoyo (junk),

The set that I was looking at was an import, but looks pretty much like
Mitutoyo. Would you agree with a previous poster who suggested that a bore
gage isn't worth having if it isn't a big name?

Most dial bores will. What size range are you looking at?

I'd *like* .5" - 6", but what I see available for a reasonable price is
1.4" - 6".

--
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Mike Graham | Metalworker, rustic, part-time zealot.
|
http://www.metalmangler.com| Caledon, Ontario, Canada

One other thing I don't think has been mentioned it the setting of the
gages. Reguardless of the brand of gauge you use you need an accurate
setting master. While a micrometer and stand will do, it's not always
the easiest way to do it. In production situations the best option is a
ring gauge, custom made to the size of your part. Of course this could
get expensive very fast as the ring gage could cost more than the bore
gage. In my last shop we used Sunnen bore gages, They come with a
setting master that can adapter to any size in its range and holds the
bore gage in position for proper setting. We would use these for
checking bores on the Jigbore with +/-.0002" tolerances.
I would stay away from the really cheap sets, but I found the
Mitutoyo gages to hold up pretty good.

Mike Graham wrote:
In article , Lennie the Lurker wrote:


Depends. If you're doing production, they would be indispensable. If
you're doing one off in a tool room situation, maybe. For general
machining, probably not.


I can see how the 'dial' aspect of them would be very important when
looking for the condition of a bore... when looking for bulges, waisting,
out of round, etc. I'm primarily looking for a fast and accurate way to see
where I am in the boring process so that after I take my final 40 thou cut,
I'm where I want to be.


Federal, Starrett, Standard and Mitutoyo (junk),


The set that I was looking at was an import, but looks pretty much like
Mitutoyo. Would you agree with a previous poster who suggested that a bore
gage isn't worth having if it isn't a big name?


Most dial bores will. What size range are you looking at?


I'd *like* .5" - 6", but what I see available for a reasonable price is
1.4" - 6".


--
--------------------------------------------------------------------------

James P Crombie

Summerside Machinist
Prince Edward Island Amateur Astronomer
Canada 3D Designer

E-mail
Astronomy webpage http://www.jamescrombie.com
Rhinoceros 3D webpage http://www.jamescrombie.com/rhino/
Mirror Grinder page http://www.jamescrombie.com/pics/
--------------------------------------------------------------------------

In article ,
Mike Graham wrote:
I've never used a bore gage (dial bore gage, whatever). I've only used
inside mics (of the tubular variety) and telescopic gages. Are bore gages
sufficiently snazzy to make them worth the relatively upper-crusty price
tag? A set of intramics is absolutely out of the question. 8-)

Well ... I've never used one of the dial bore gauges either, but
I do have a pretty complete set of Intrimics now -- in the range from
the smallest to about 1.8", and a few in other sizes. This is thanks to
haunting eBay for a while. One of the best buys was when two identical
sets of four were up for auction at the same time, and the one closing
second had a really splashy fancy description full of images, while the
one closing first was just good enough. I opted to bid on the one
closing first, since its price was a lot lower. I got it, and at the
time that it closed, the other lot was already higher. One interesting
thing is that the higher-priced lot did not have the proper wrenches
needed for calibration and for installing/removing the (include)
extension tube set. I think that I got the better deal by far. (The
other one had current calibration stickers, which they made a big thing
of, but both came with two setting rings (each ring covered the high end
of one mic and the low end of the other).

So -- if you're not in a hurry, you might try tracking eBay for
the sizes which you need most.

Good Luck,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

There are two more things to consider. First, if you are looking at used
ones, there is the issue of how accurate the movement is. Secondly, if the
gage does not come will all the extension points, buying them can get
expensive (If even available.). Extension can easily exceed $25 each, and
sometimes it requires as many as 7 extensions to give a full range for a
given bore gage. So a $50 Ebay 'buy' may not be such a good deal.

"Craig" wrote in message
om...
Mike Graham wrote in message
. ..
I've never used a bore gage (dial bore gage, whatever). I've only used
inside mics (of the tubular variety) and telescopic gages. Are bore
gages
sufficiently snazzy to make them worth the relatively upper-crusty price
tag? A set of intramics is absolutely out of the question. 8-)

If you need the accuracy, they are great. We've got at least 30 Mohr
gage kits here at work. Our kits can cover everything from .128" all
the way up to .500". Kits consist of a digital head, various extension
pins and the necessary ball ends and check rings. Takes about 30
seconds to set one up. When you have to do hole diameter checks on
500-600 holes in a single installation, it makes for fast inspection.
Don't know what the kits cost, but I believe that you can start with
just the head and one size set up.

Craig C.

Mike
My last shop had 3 sets of the Mitutoyo Tri-mikes, .25-8" plus some
extras where the use required. I used to do several specific jobs so I
kept 5-6 and 6-7" one at the L&S I ran. Plus a set of 8-20" stick
mikes. If your production requires that +/- .0005 measurment then they
are definetly worth the investment. The speed and accuracy they provide
can pay for itself.
Of course there is such a thing as getting spoiled with all the nice
tools :-) and if I was setting up my own shop I would have to look
pretty hard at the costs. I'm still kicking myself for not picking up a
set of tri-mikes years ago when my employer surplused a bunch of
measuring tools. I did get a quite a bit of stuff then (calipers 6 &12"
,6"depth mic, 0-4" mic set and 6&12" squares, rad gages) all digital
mics and calipers.

Mike Graham wrote:
In article , DoN. Nichols wrote:


So -- if you're not in a hurry, you might try tracking eBay for
the sizes which you need most.


I don't know what sizes I need the most. 8-) 6" today, 1" tomorrow.
Although we manufacture stuff, most of the time it's a jobbing shop making
one-offs.


--
--------------------------------------------------------------------------

James P Crombie

Summerside Machinist
Prince Edward Island Amateur Astronomer
Canada 3D Designer

E-mail
Astronomy webpage http://www.jamescrombie.com
Rhinoceros 3D webpage http://www.jamescrombie.com/rhino/
Mirror Grinder page http://www.jamescrombie.com/pics/
--------------------------------------------------------------------------

In article , James P Crombie wrote:

measuring tools. I did get a quite a bit of stuff then (calipers 6 &12"
,6"depth mic, 0-4" mic set and 6&12" squares, rad gages) all digital
mics and calipers.

This brings up something that has been annoying me of late. Everybody has
a 0-1" mic. Most people probably have several (I have at least four) yet if
you want to buy a set of mics they always include the 0-1". I would *love*
to be able to buy a 1-4" set of mics. Sigh.

--
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Mike Graham | Metalworker, rustic, part-time zealot.
|
http://www.metalmangler.com| Caledon, Ontario, Canada

I have 2 sets of 0-4", the Mitutoyo solid type with the heat sheilds and
the 0-4 digimatic set that I got for $300 back in 1990 :-) I kept the
standard mics at home and the Digimatic at work. I found I rarely used
the 2-3 or 3-4 but occasionally they came in handy. Most of the
measurements I made were using the tri-mics, stick mics or with a 12-16"
adjustable type mic. Big lathe, big parts :-)
But with my enforced vacation they are collecting dust in the
basement at the moment. Forget about shooting the lawyers, its those
moron bean counters that think they can save money by laying off the
highest payed(and most experienced) people in the shop. And now every
one in the shop is working 8-10 hours O/T every week.
Arrrrrrrrrgggggggg- Rant off :-)
So, whats the job market like up there at the moment? :-)

Mike Graham wrote:
In article , James P Crombie wrote:


measuring tools. I did get a quite a bit of stuff then (calipers 6 &12"
,6"depth mic, 0-4" mic set and 6&12" squares, rad gages) all digital
mics and calipers.


This brings up something that has been annoying me of late. Everybody has
a 0-1" mic. Most people probably have several (I have at least four) yet if
you want to buy a set of mics they always include the 0-1". I would *love*
to be able to buy a 1-4" set of mics. Sigh.


--
--------------------------------------------------------------------------

James P Crombie

Summerside Machinist
Prince Edward Island Amateur Astronomer
Canada 3D Designer

E-mail
Astronomy webpage http://www.jamescrombie.com
Rhinoceros 3D webpage http://www.jamescrombie.com/rhino/
Mirror Grinder page http://www.jamescrombie.com/pics/
--------------------------------------------------------------------------

Mike Graham wrote in message . ..
In article , Lennie the Lurker wrote:

I can see how the 'dial' aspect of them would be very important when
looking for the condition of a bore... when looking for bulges, waisting,
out of round, etc. I'm primarily looking for a fast and accurate way to see
where I am in the boring process so that after I take my final 40 thou cut,
I'm where I want to be.

Hmmm. Most dial bores, or their electronic versions thereof, have a
small range from the setting, usually less than 20 thou. Federal make
some with a longer range, but they're three point, won't show out of
round.

Federal, Starrett, Standard and Mitutoyo (junk),

The set that I was looking at was an import, but looks pretty much like
Mitutoyo. Would you agree with a previous poster who suggested that a bore
gage isn't worth having if it isn't a big name?

Again, this depends on what you want to do with it. I've seen some
pretty decent homebuilds, and I've seen junk with big names on it.
I'll admit a strong preference to Standard, I like the way the
indicators are made, but the Federal, I think they called them the
"500" series are good too. Both pricey as hell, hard to justify if
you don't have need for .0001" accuracy or enough pieces to make it
worth while. (The indicators on the Standard are shockproof, and they
don't mean maybe. You could destroy the gaging foot, but the
indicator wouldn't be hurt.)

Most dial bores will. What size range are you looking at?

I'd *like* .5" - 6", but what I see available for a reasonable price is
1.4" - 6".

Let me look through my junk, I had a bunch of them but I've also sold
a bunch, don't really know what I have left, and you may have to learn
to cut 3/8"-40 threads to make tail pins for them. I'll send an email
when I look them up, might be a day or two, rebuilding a Boyar-Schultz
surface grinder, and the owner wants it. Think there's a few
Intrimikes down there too, but metric, and not a complete set. I know
I don't have anything below 1", maybe not below 2", but I've got so
damn much, I don't know what's down there.