There's been a role reversal at my place...

Whenever "The Kid" is home, I watch him machine to learn. he edge found a
part (in 15 seconds!) by flicking the edgefinder to make it wobble and then
turning the crank till it was on center.

I've always cranked till the finder "kicks" to one side. I don't have his
accurate eye sight and feel to do it that way. My results weren't as
repeatable ( I tried after he left) so I'm back to the "kick"

Karl

Karl Townsend wrote:
There's been a role reversal at my place...

Whenever "The Kid" is home, I watch him machine to learn. he edge
found a part (in 15 seconds!) by flicking the edgefinder to make it
wobble and then turning the crank till it was on center.

I've always cranked till the finder "kicks" to one side. I don't
have his accurate eye sight and feel to do it that way. My results
weren't as repeatable ( I tried after he left) so I'm back to the
"kick"
Karl

I just found out about the "kick" ... Had the mill all of two weeks now ,
got a half-decent vise and some essential tooling . My first project will be
a mist cooler (from plans in the dropbox) , so I can do the second project -
a taper attachment for the lathe . Then I can finish the mandrels to lap the
bearing races in the motor and tranny for the '39 Harley .
See , Honey , I told you I needed this mill to do stuff for the bikes !
--
Snag
'90 Ultra "Strider"
'39 WLDD "Popcycle"
Buncha cars and a truck

On Tue, 22 Jul 2008 20:24:43 -0500, "Karl Townsend"
wrote:

There's been a role reversal at my place...

Whenever "The Kid" is home, I watch him machine to learn. he edge found a
part (in 15 seconds!) by flicking the edgefinder to make it wobble and then
turning the crank till it was on center.

I've always cranked till the finder "kicks" to one side. I don't have his
accurate eye sight and feel to do it that way. My results weren't as
repeatable ( I tried after he left) so I'm back to the "kick"

Karl


Greetings Karl,
I also let it kick. But when it does I figure that the edge finder is
..0005" past the edge. So with the digital readout I move the table
0994 when using the .200 dia. edge finder and call that zero. Always
works for me.
Eric

I've got one of the lazer finders from Little Machine shop. It has a very fine focus lens. If you
make the dot almost invisible then split the beam with about half on the work, it will get you
within a gnats ass of the edge.

Bob
Swinney



Bob Swinney
"Karl Townsend" wrote in message
anews.com...
There's been a role reversal at my place...

Whenever "The Kid" is home, I watch him machine to learn. he edge found a
part (in 15 seconds!) by flicking the edgefinder to make it wobble and then
turning the crank till it was on center.

I've always cranked till the finder "kicks" to one side. I don't have his
accurate eye sight and feel to do it that way. My results weren't as
repeatable ( I tried after he left) so I'm back to the "kick"

Karl


** Posted from http://www.teranews.com **

Karl Townsend wrote:
There's been a role reversal at my place...

Whenever "The Kid" is home, I watch him machine to learn. he edge found a
part (in 15 seconds!) by flicking the edgefinder to make it wobble and then
turning the crank till it was on center.

I've always cranked till the finder "kicks" to one side. I don't have his
accurate eye sight and feel to do it that way. My results weren't as
repeatable ( I tried after he left) so I'm back to the "kick"

I use the method your son uses. It just seemed like the obvious way to me.
So if you touch the work with a spinning edge finder it will kick to one
side? I will try it and see how it goes.

Thanks,
BobH

I go in with it wobbeling,

watch it center up

zero the DRO,

crank a bit more and watch it "jump" (I don't call it kick) sideways,

recheck the DRO and if it *ISN'T* plus .0005 or .001, I do it again...

FWIW an old timer told me to take it to the "jump" and call it zero (like
you do).... go figure

I also find it works best at about 1000 rpm... "jumps" real fast then

--.- Dave

"Karl Townsend" wrote in message
anews.com...
There's been a role reversal at my place...

Whenever "The Kid" is home, I watch him machine to learn. he edge found a
part (in 15 seconds!) by flicking the edgefinder to make it wobble and
then turning the crank till it was on center.

I've always cranked till the finder "kicks" to one side. I don't have his
accurate eye sight and feel to do it that way. My results weren't as
repeatable ( I tried after he left) so I'm back to the "kick"

Karl

Greetings Karl,
I also let it kick. But when it does I figure that the edge finder is
.0005" past the edge. So with the digital readout I move the table
0994 when using the .200 dia. edge finder and call that zero. Always
works for me.
Eric

That's exactly what "The Kid" told me, but he said more like a thou past.
Then he went on to say edge finding is only for hack work. If you need it
accurate use the dial indicator. Now, it really ****es me off on how fast he
can accurately indicate in a vice (for square) and the part on both side.

Karl

On Jul 22, 8:24*pm, "Karl Townsend"
wrote:
There's been a role reversal at my place...

Whenever "The Kid" is home, I watch him machine to learn. he edge found a
part (in 15 seconds!) by flicking the edgefinder to make it wobble and then
turning the crank till it was on center.

I've always cranked till the finder "kicks" to one side. *I don't have his
accurate eye sight and feel to do it that way. My results weren't as
repeatable ( I tried after he left) so I'm back to the "kick"

Karl

I do it your way, Karl. That's what they taught me back in the 50's,
when I was an apprentice and I don't see any reason to change, as it
has always produced satisfactory results for me.

Lewis.

*****

On Jul 23, 9:58 pm, " wrote:
On Jul 22, 8:24 pm, "Karl Townsend"
wrote:

There's been a role reversal at my place...

Whenever "The Kid" is home, I watch him machine to learn. he edge found a
part (in 15 seconds!) by flicking the edgefinder to make it wobble and then
turning the crank till it was on center.

I've always cranked till the finder "kicks" to one side. I don't have his
accurate eye sight and feel to do it that way. My results weren't as
repeatable ( I tried after he left) so I'm back to the "kick"

Karl

I do it your way, Karl. That's what they taught me back in the 50's,
when I was an apprentice and I don't see any reason to change, as it
has always produced satisfactory results for me.

Lewis.

*****

I got shown another method at school on Tuesday - chuck up a dowel
pin, say 10mm, and coat it with marking pen - bring work to spinning
pin until you just see a faint line appear on the down as the job
wipes it off. Then add 5mm (ie, 1/2 the pin diameter) and you will
have your edge...then add 1/2 job diameter if you want the centre -
zero your DRO - this was part of the setup for an indexing exercise..

Andrew VK3BFA.

On Tue, 22 Jul 2008 20:24:43 -0500, "Karl Townsend"
wrote:

There's been a role reversal at my place...

Whenever "The Kid" is home, I watch him machine to learn. he edge found a
part (in 15 seconds!) by flicking the edgefinder to make it wobble and then
turning the crank till it was on center.

I've always cranked till the finder "kicks" to one side. I don't have his
accurate eye sight and feel to do it that way. My results weren't as
repeatable ( I tried after he left) so I'm back to the "kick"

Karl

I go for the kick. Watching the wobble require that one can see .001"
or less of wobble, while the kick is considerably less subtle. The
kick seems to be accurate and repeatable to .0005 or so, close enough
for me. I usually check it once or twice to see that I get the same
readings.

A good centerfinder (Brown & Sharpe) works considerably better than a
Chinese knockoff for just a few bux more.

On Wed, 23 Jul 2008 05:30:37 -0500, "Karl Townsend"
wrote:


Greetings Karl,
I also let it kick. But when it does I figure that the edge finder is
.0005" past the edge. So with the digital readout I move the table
0994 when using the .200 dia. edge finder and call that zero. Always
works for me.
Eric

That's exactly what "The Kid" told me, but he said more like a thou past.
Then he went on to say edge finding is only for hack work. If you need it
accurate use the dial indicator. Now, it really ****es me off on how fast he
can accurately indicate in a vice (for square) and the part on both side.

Karl


I've been machining for over 30 years. A few times I put the vise on
the machine and it was less than a few tenths out. But for the last
few years when I put the vise on the mill it's usually within .010. So
often that it can't be chance. Just got so used to where it's supposed
to be.
Eric

On Tue, 22 Jul 2008 20:24:43 -0500, "Karl Townsend"
wrote:

There's been a role reversal at my place...

Whenever "The Kid" is home, I watch him machine to learn. he edge found a
part (in 15 seconds!) by flicking the edgefinder to make it wobble and then
turning the crank till it was on center.

I've always cranked till the finder "kicks" to one side. I don't have his
accurate eye sight and feel to do it that way. My results weren't as
repeatable ( I tried after he left) so I'm back to the "kick"

Karl


Last year at EASTEC I picked up a Hermann Schmidt edge finder. Very
accurate and excelent repetition. Worth the extra $$$ for quailty!

You can rest assured that I do NOT let my students borrow it!!!

http://www.hermannschmidt.com/

Errol Groff

Instructor, Machine Tool Department
H.H. Ellis Technical High School
Danielson, CT

BobH wrote:
Karl Townsend wrote:
There's been a role reversal at my place...

Whenever "The Kid" is home, I watch him machine to learn. he edge found
a part (in 15 seconds!) by flicking the edgefinder to make it wobble
and then turning the crank till it was on center.

I've always cranked till the finder "kicks" to one side. I don't have
his accurate eye sight and feel to do it that way. My results weren't
as repeatable ( I tried after he left) so I'm back to the "kick"

I use the method your son uses. It just seemed like the obvious way to
me. So if you touch the work with a spinning edge finder it will kick to
one side? I will try it and see how it goes.

The instructions that came with my edge finders say to use the kick. I
hadn't heard or thought about that idea until I read the instructions and
tried it.

I certainly feel like using the kick makes the edge finding more
repeatable. But I do wonder about what the true position of the edge is
when you use the kick method.

Since I don't own a mill and have only used my edge finders with the
school's mill, (and the class is now over) I can't spend the time to
experiment and try to answer that question. The idea of assuming it's
5/10,000 over suggested by the OP seems reasonable.

I guess to experiment, what I might do is machine a piece to an accurate
width. Locate it with the edge finder, and then machine 1/1000 off
opposite edges with an offset so I could mic the new widths relative to the
old width, and relative to each new cut and see how the numbers worked out.
That is, I would leave the piece so I could mic it from an old edge, to one
new edge on one side, and from the other new edge to the opposite old edge,
and then from new edge to new edge.

The goal of course is to find a way to use the edge finder so that these
1/1000 cuts would take an equal amount off of both edges after setting the
location with the edge finder.

--
Curt Welch http://CurtWelch.Com/
http://NewsReader.Com/

I just had to jump in with a mildly off topic response: Yesterday I was
showing a student how the edge finder did the 'jump' when it contacted
the surface (and the usual discussion about the .0005" to .001"
difference from the 'real' edge) when the jump went the wrong direction.
!!@##@!!! I had been running it in reverse! cue to very red faced
instructor.

Karl Townsend wrote:
There's been a role reversal at my place...

Whenever "The Kid" is home, I watch him machine to learn. he edge found a
part (in 15 seconds!) by flicking the edgefinder to make it wobble and then
turning the crank till it was on center.

I've always cranked till the finder "kicks" to one side. I don't have his
accurate eye sight and feel to do it that way. My results weren't as
repeatable ( I tried after he left) so I'm back to the "kick"

Karl

On Jul 24, 2:23 pm, RoyJ wrote:
I just had to jump in with a mildly off topic response: Yesterday I was
showing a student how the edge finder did the 'jump' when it contacted
the surface (and the usual discussion about the .0005" to .001"
difference from the 'real' edge) when the jump went the wrong direction.
!!@##@!!! I had been running it in reverse! cue to very red faced
instructor.

Was it a Bridgeport? - the ones at my college do that, when you go
from H to L range, on one of them you need to reverse the motor.....I
have to work it out each time.....why its done that way, no idea......

Andrew VK3BFA.

RoyJ wrote:
I just had to jump in with a mildly off topic response: Yesterday I was
showing a student how the edge finder did the 'jump' when it contacted
the surface (and the usual discussion about the .0005" to .001"
difference from the 'real' edge) when the jump went the wrong direction.
!!@##@!!! I had been running it in reverse! cue to very red faced
instructor.
What's the diff? An edge finder is just about the only thing you'll
ever put
in a machine tool spindle that doesn't care which way it is turning.

Jon

wrote:
On Jul 24, 2:23 pm, RoyJ wrote:

I just had to jump in with a mildly off topic response: Yesterday I was
showing a student how the edge finder did the 'jump' when it contacted
the surface (and the usual discussion about the .0005" to .001"
difference from the 'real' edge) when the jump went the wrong direction.
!!@##@!!! I had been running it in reverse! cue to very red faced
instructor.


Was it a Bridgeport? - the ones at my college do that, when you go
from H to L range, on one of them you need to reverse the motor.....I
have to work it out each time.....why its done that way, no idea......
It's just the way the back gear train works. A lathe back gear inserts
two reversals, so the spindle ends up going the same way. The
Bridgeport uses a belt drive to turn the back gear, so engaging the gear
only inserts one gear train reversal, so the spindle ends up running the
other direction. You get used to it if you use it often.

Jon

On Tue, 22 Jul 2008 20:24:43 -0500, "Karl Townsend"
wrote:

There's been a role reversal at my place...

Whenever "The Kid" is home, I watch him machine to learn. he edge found a
part (in 15 seconds!) by flicking the edgefinder to make it wobble and then
turning the crank till it was on center.

I've always cranked till the finder "kicks" to one side. I don't have his
accurate eye sight and feel to do it that way. My results weren't as
repeatable ( I tried after he left) so I'm back to the "kick"

Karl


I can't see why it would make any difference to the edge finder which
way the spindle is turning. Other than if you are used to seeing it
kick in one direction it would be disconcerting to have iti kick the
opposite way.

As to which way the spindle turns in high or low range I tell my
students at least a zillion time a year LOOK at the tool when you
start the spindle. Then you will SEE which way it is going. Saves on
end mills and drill points to know which way the tool (spindle) is
turning.

Errol Groff

On Jul 24, 4:20 pm, Errol Groff wrote:
On Tue, 22 Jul 2008 20:24:43 -0500, "Karl Townsend"

wrote:
There's been a role reversal at my place...

Whenever "The Kid" is home, I watch him machine to learn. he edge found a
part (in 15 seconds!) by flicking the edgefinder to make it wobble and then
turning the crank till it was on center.

I've always cranked till the finder "kicks" to one side. I don't have his
accurate eye sight and feel to do it that way. My results weren't as
repeatable ( I tried after he left) so I'm back to the "kick"



Karl

I can't see why it would make any difference to the edge finder which
way the spindle is turning. Other than if you are used to seeing it
kick in one direction it would be disconcerting to have iti kick the
opposite way.

As to which way the spindle turns in high or low range I tell my
students at least a zillion time a year LOOK at the tool when you
start the spindle. Then you will SEE which way it is going. Saves on
end mills and drill points to know which way the tool (spindle) is
turning.

Errol Groff

It doesn't really make a difference whether the spindle is running cw
or ccw, as the edge finder will still jump.. Just that if the edge
you're 'finding' is the X- edge and you're running the spindle ccw it
will jump toward you and is easier to see the jump, IMHO.. On Y edges
the jump is sideways so easy to see in either direction.. One of my
edge finders [I think from SPI] has a very small flat ground on the .
200 diameter so it gives you an audible as well as a visual indication
of the jump.. Just my $0.27 worth..

Karl Townsend wrote:
There's been a role reversal at my place...

Whenever "The Kid" is home, I watch him machine to learn. he edge found a
part (in 15 seconds!) by flicking the edgefinder to make it wobble and then
turning the crank till it was on center.

I've always cranked till the finder "kicks" to one side. I don't have his
accurate eye sight and feel to do it that way. My results weren't as
repeatable ( I tried after he left) so I'm back to the "kick"

I don't know how well the technique would work for you guys who don't
work with mushy stuff, but I made a gizmo that allows me to locate a
corner of a workpiece (and either zero all three axes or just report the
x, y, and z coordinates of the corner.

There're photos at http://www.iedu.com/DeSoto/SuperZero/ and a detailed
description at http://www.iedu.com/DeSoto/SuperZero/ReadMe.html

I think I know how to make the little bugger work on "real" machinery,
but don't have any to play with. :-)

Anyhoo, I thought it might spark a few ideas...

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/