Hello all,

My latest project is to make four copies of a 90 degree angle (cut from
extruded Al) with a couple of slots on one face and a window on the
other. The slots are killing me, but I need them small more than I need
them accurate or pretty - I do not have a small enough endmill to rough
and then clean up the edges. I have been taking three passes of about
0.040 inch, which gives ok results.

The windows are giving me an opportunity to try some of Harold's advice.
Basically, I am rough cutting "with the dials". With the
understanding that I leave some metal to remove later, I go to the
corner closest to 0,0, lock transverse axis, plunge, cut longitudinally
to the limit of the rough cut. Unlock trans, lock longitudinal, cut
transverse with the dial to the limit. Up, back to the corner, and go
the other direction (down/right vs. right/down) to release the waste.

At this point, I make a sketch with the dial readings to expect at each
corner. You might detect a little uncertainty about the first cut on
the top and left sides - that's for good reason With the rough cut
complete, it seems that all I need to do is watch for the endmill
approaching the margin and then look at the dial for when to stop; the
backlash correction is built into the numbers, and I simply revise them
as I clean up the edges based on measurements.

Reasonable? Better ideas?

The parts in question are small, forcing me to use smaller cutters than
I ordinarily would - 1/2 inch is a nice compromise of strength and
dexterity for me. In this case, I am down to 3/16 inch. My clamping is
questionable; a fixture would probably be in order as the parts are
small enough to be difficult to grab. I noticed the machine vibrating
some a couple of times, and wondered whether a higher spindle speed
might be needed. Any recommendations?

In other news, I _finally_ ordered steel rules today, along with a lot
of other loose junk (angle plates etc.), and a couple of mid-price work
stops, one that clamps on a vise jaw and one that I _think_ mounts via a
t-nut (or at least will when I'm done with itg).

Bill

On Thu, 15 Dec 2005 03:17:37 GMT, Bill Schwab
wrote:

Hello all,

My latest project is to make four copies of a 90 degree angle (cut from
extruded Al) with a couple of slots on one face and a window on the
other. The slots are killing me, but I need them small more than I need
them accurate or pretty - I do not have a small enough endmill to rough
and then clean up the edges. I have been taking three passes of about
0.040 inch, which gives ok results.

The windows are giving me an opportunity to try some of Harold's advice.
Basically, I am rough cutting "with the dials". With the
understanding that I leave some metal to remove later, I go to the
corner closest to 0,0, lock transverse axis, plunge, cut longitudinally
to the limit of the rough cut. Unlock trans, lock longitudinal, cut
transverse with the dial to the limit. Up, back to the corner, and go
the other direction (down/right vs. right/down) to release the waste.

At this point, I make a sketch with the dial readings to expect at each
corner. You might detect a little uncertainty about the first cut on
the top and left sides - that's for good reason With the rough cut
complete, it seems that all I need to do is watch for the endmill
approaching the margin and then look at the dial for when to stop; the
backlash correction is built into the numbers, and I simply revise them
as I clean up the edges based on measurements.

Reasonable? Better ideas?

The parts in question are small, forcing me to use smaller cutters than
I ordinarily would - 1/2 inch is a nice compromise of strength and
dexterity for me. In this case, I am down to 3/16 inch. My clamping is
questionable; a fixture would probably be in order as the parts are
small enough to be difficult to grab. I noticed the machine vibrating
some a couple of times, and wondered whether a higher spindle speed
might be needed. Any recommendations?

In other news, I _finally_ ordered steel rules today, along with a lot
of other loose junk (angle plates etc.), and a couple of mid-price work
stops, one that clamps on a vise jaw and one that I _think_ mounts via a
t-nut (or at least will when I'm done with itg).

Bill
====================
I don't know your overall sizes, but I have had good results
using magnetic base dial drop indicators and ignoring the dials.
I have three bases (2) 1 inch and (1) 2 inch indicators which I
use on both the Emco lathe and mill. My eyes are starting to go
and the dials are much easier to read. They also eliminate the
backlash problem and can show you how much things shift when you
tighten the clamps. Also is real eye opener when you lean on
the machine.

Poor man's digital readout.

Uncle George

I don't know your overall sizes, but I have had good results
using magnetic base dial drop indicators and ignoring the dials.
I have three bases (2) 1 inch and (1) 2 inch indicators which I
use on both the Emco lathe and mill. My eyes are starting to go
and the dials are much easier to read. They also eliminate the
backlash problem and can show you how much things shift when you
tighten the clamps. Also is real eye opener when you lean on
the machine.

Poor man's digital readout.

One of these days I will weaken and buy a couple of 2 inch (bigger if I
can get cheap ones) plunge indicators to play around with this idea.
Dumb question: where/how do you mount the indicators? Do you do
anything special to protect them from chips and oil?

Bill

The windows are giving me an opportunity to try some of Harold's advice.
Basically, I am rough cutting "with the dials". With the
understanding that I leave some metal to remove later, I go to the
corner closest to 0,0, lock transverse axis, plunge, cut longitudinally
to the limit of the rough cut. Unlock trans, lock longitudinal, cut
transverse with the dial to the limit. Up, back to the corner, and go
the other direction (down/right vs. right/down) to release the waste.

I wouldn't unlock, and relock. Instead, I would put a slight drag on each
axis and leave it there while I make the cuts. Older mills especially will
move quite a bit when you play with the locks.

On Thu, 15 Dec 2005 04:29:58 GMT, Bill Schwab
wrote:
I don't know your overall sizes, but I have had good results
using magnetic base dial drop indicators and ignoring the dials.
I have three bases (2) 1 inch and (1) 2 inch indicators which I
use on both the Emco lathe and mill. My eyes are starting to go
and the dials are much easier to read. They also eliminate the
backlash problem and can show you how much things shift when you
tighten the clamps. Also is real eye opener when you lean on
the machine.
Poor man's digital readout.
===================
One of these days I will weaken and buy a couple of 2 inch (bigger if I
can get cheap ones) plunge indicators to play around with this idea.
Dumb question: where/how do you mount the indicators? Do you do
anything special to protect them from chips and oil?
Bill
==================
I find the standard jointed dial indicator holder to be minimally
useful in this situation.

I have several indicators with the magnetic back. Use the for 2
of the axis and as a lathe "stop"

Also bought 2 of the mightymag holders -- use these to mount my 2
inch stroke holder. With a set of 123 blocks I can get good
accuracy up to 5 inches which is all I ever needed so far.

No particular care taken to keep oil out but several indicators
do have oil inside.

I use the PRC Enco indicators for this. Can't tell any
difference between then and my B&S/Mitutoyo drop indicators
except these feel a little more "gritty." Top quality indicators
may be better in a production environment.

Watch the Enco sales fliers. Get the indicator/mightymag copy
and a set of contact points for less than 15$. Your choice of
black or white dial.

Uncle George

==================
I find the standard jointed dial indicator holder to be minimally
useful in this situation.

I have several indicators with the magnetic back. Use the for 2
of the axis and as a lathe "stop"

Also bought 2 of the mightymag holders -- use these to mount my 2
inch stroke holder. With a set of 123 blocks I can get good
accuracy up to 5 inches which is all I ever needed so far.

Thanks for the detail. Have you posted pictures of this anywhere?
Please don't do so just on my account, but if you have gone to the
trouble, I would enjoy seeing the setup.



No particular care taken to keep oil out but several indicators
do have oil inside.

I use the PRC Enco indicators for this. Can't tell any
difference between then and my B&S/Mitutoyo drop indicators
except these feel a little more "gritty." Top quality indicators
may be better in a production environment.

I am by no means production oriented in the volume sense. The four
clips are done, and that was a big run Two of them are pretty good;
two more are more than useable but nothing to write home about. I just
received a shipping notice that, among other things, tells me my stops
are on the way. Too late for this batch, but I now have first hand
understanding of why they are helpful.


Watch the Enco sales fliers. Get the indicator/mightymag copy
and a set of contact points for less than 15$. Your choice of
black or white dial.

Thanks!

Bill

I have used the dials as you do for years. Finally, about 5 years ago I
bought the Shooting Star 2 axis DRO and installed in on my well worn
mill. It has worked very well for me. Well worth the money. I just
wish they had the new design when I got mine.

Pete Stanaitis
----------------------


F. George McDuffee wrote:

On Thu, 15 Dec 2005 03:17:37 GMT, Bill Schwab
wrote:


Hello all,

My latest project is to make four copies of a 90 degree angle (cut from
extruded Al) with a couple of slots on one face and a window on the
other. The slots are killing me, but I need them small more than I need
them accurate or pretty - I do not have a small enough endmill to rough
and then clean up the edges. I have been taking three passes of about
0.040 inch, which gives ok results.

The windows are giving me an opportunity to try some of Harold's advice.
Basically, I am rough cutting "with the dials". With the
understanding that I leave some metal to remove later, I go to the
corner closest to 0,0, lock transverse axis, plunge, cut longitudinally
to the limit of the rough cut. Unlock trans, lock longitudinal, cut
transverse with the dial to the limit. Up, back to the corner, and go
the other direction (down/right vs. right/down) to release the waste.

At this point, I make a sketch with the dial readings to expect at each
corner. You might detect a little uncertainty about the first cut on
the top and left sides - that's for good reason With the rough cut
complete, it seems that all I need to do is watch for the endmill
approaching the margin and then look at the dial for when to stop; the
backlash correction is built into the numbers, and I simply revise them
as I clean up the edges based on measurements.

Reasonable? Better ideas?

The parts in question are small, forcing me to use smaller cutters than
I ordinarily would - 1/2 inch is a nice compromise of strength and
dexterity for me. In this case, I am down to 3/16 inch. My clamping is
questionable; a fixture would probably be in order as the parts are
small enough to be difficult to grab. I noticed the machine vibrating
some a couple of times, and wondered whether a higher spindle speed
might be needed. Any recommendations?

In other news, I _finally_ ordered steel rules today, along with a lot
of other loose junk (angle plates etc.), and a couple of mid-price work
stops, one that clamps on a vise jaw and one that I _think_ mounts via a
t-nut (or at least will when I'm done with itg).

Bill

====================
I don't know your overall sizes, but I have had good results
using magnetic base dial drop indicators and ignoring the dials.
I have three bases (2) 1 inch and (1) 2 inch indicators which I
use on both the Emco lathe and mill. My eyes are starting to go
and the dials are much easier to read. They also eliminate the
backlash problem and can show you how much things shift when you
tighten the clamps. Also is real eye opener when you lean on
the machine.

Poor man's digital readout.

Uncle George

On Sat, 17 Dec 2005 07:36:03 GMT, Bill Schwab
wrote:
==================
I find the standard jointed dial indicator holder to be minimally
useful in this situation.
I have several indicators with the magnetic back. Use the for 2
of the axis and as a lathe "stop"
Also bought 2 of the mightymag holders -- use these to mount my 2
inch stroke holder. With a set of 123 blocks I can get good
accuracy up to 5 inches which is all I ever needed so far.
=========
Thanks for the detail. Have you posted pictures of this anywhere?
Please don't do so just on my account, but if you have gone to the
trouble, I would enjoy seeing the setup.
No particular care taken to keep oil out but several indicators
do have oil inside.

I use the PRC Enco indicators for this. Can't tell any
difference between then and my B&S/Mitutoyo drop indicators
except these feel a little more "gritty." Top quality indicators
may be better in a production environment.

I am by no means production oriented in the volume sense. The four
clips are done, and that was a big run Two of them are pretty good;
two more are more than useable but nothing to write home about. I just
received a shipping notice that, among other things, tells me my stops
are on the way. Too late for this batch, but I now have first hand
understanding of why they are helpful.


Watch the Enco sales fliers. Get the indicator/mightymag copy
and a set of contact points for less than 15$. Your choice of
black or white dial.

Thanks!

Bill
See 3rd picture down at
http://www.mcduffee-associates.us/ma...g/rearcoth.htm

Shows a magnetic back dial indicator for the mill Z "knee" and a
mightymag for the table Y. Both drop indicators are PRC Encos.
Test indicator is also an Enco 15-0-15 for general use, but I
have a 0.0001 German made Maier test indicator for very accurate
work.

I don't yet have all the pictures uploaded where I have the
captions.

FWIW -- the upsidedown rear mounted cutoff [parting off] tool
holder is a very worthwhile project.

Uncle George

George,

See 3rd picture down at
http://www.mcduffee-associates.us/ma...g/rearcoth.htm

That's a nice page! Early on, I tried placing an on/off mag base on the
flat(ter) portions of the base of my machine, without success. The base
sticks, but it never sits flat so any readings would be questionable.
The mighty mag clone you suggest is worth a shot. If nothing else, it
would be nice to see how much my machine moves around when the locks are
applied. So far, I suspect I get better results using them than not,
but I appreciate your raising the question.

With the power feed in place, it is not super easy to feel the
longitudinal gib resistance. At one point, I might have been having
problems because the gib was not properly tensioned and not so much
because I needed the locks. Since I need to remove the feed to get to
the left oil port, I am trying to remember to note the gib resistance
while it is removed.

I was envisioning a longitudinal indicator too. Is there any particular
reason you do not use one in that direction?

Thanks!

Bill

On Tue, 20 Dec 2005 07:49:34 GMT, Bill Schwab
wrote:
George,
See 3rd picture down at
http://www.mcduffee-associates.us/ma...g/rearcoth.htm
--------------------
That's a nice page! Early on, I tried placing an on/off mag base on the
flat(ter) portions of the base of my machine, without success. The base
sticks, but it never sits flat so any readings would be questionable.
The mighty mag clone you suggest is worth a shot. If nothing else, it
would be nice to see how much my machine moves around when the locks are
applied. So far, I suspect I get better results using them than not,
but I appreciate your raising the question.
You can also use "kentucky windage" and off-set the move when the
clamp is tightened it will be to put the table/slide where it
should be. V-way machines are much less prone to this than the
round column "knee" that the Emco has.

With the power feed in place, it is not super easy to feel the
longitudinal gib resistance. At one point, I might have been having
problems because the gib was not properly tensioned and not so much
because I needed the locks. Since I need to remove the feed to get to
the left oil port, I am trying to remember to note the gib resistance
while it is removed.
I have not yet had occasion to try this but several people have
told me of good results by applying a thin teflon or HDPE [high
density polyethylene] based tape to the sliding surface of the
gib and using only light/thin oil. See:
http://www.garlandmfg.com/plastics/pstape.html
http://www.usplastic.com/catalog/pro...E27 07FC8E087
If you try this let us know how it worked as I am sure many
people are in the same situation.
I was envisioning a longitudinal indicator too. Is there any particular
reason you do not use one in that direction?
Thanks!
Bill
=============
Did not need micrometer location accuracy along that axis [X]
[cutting slot] so did not put an indicator there. I have never
had occassion to machine anything that required micrometer
accuracy on all three axis at the same time.

If you think you may be doing this sort of thing extensively you
may want to consider fabricating dial indicator holders and
possibly modifying your table/slide [drill & tap] to mount the
indicators/holders.

Uncle George

George,

You can also use "kentucky windage" and off-set the move when the
clamp is tightened it will be to put the table/slide where it
should be. V-way machines are much less prone to this than the
round column "knee" that the Emco has.

My machine has a round column, but dovetail ways. Does that change
anything?


With the power feed in place, it is not super easy to feel the
longitudinal gib resistance. At one point, I might have been having
problems because the gib was not properly tensioned and not so much
because I needed the locks. Since I need to remove the feed to get to
the left oil port, I am trying to remember to note the gib resistance
while it is removed.

I have not yet had occasion to try this but several people have
told me of good results by applying a thin teflon or HDPE [high
density polyethylene] based tape to the sliding surface of the
gib and using only light/thin oil. See:
http://www.garlandmfg.com/plastics/pstape.html
http://www.usplastic.com/catalog/pro...E27 07FC8E087
If you try this let us know how it worked as I am sure many
people are in the same situation.

Interesting. What is that intended to fix? Is the idea to give tighter
fit with less wear? So far, I appear to fine as long as I have the gib
properly adjusted, it just took me a while to realize the consequences
of the obvious: one feels the feed more than the gib.

If any 31 Bestline feed users know of a good alignment proceedure, I am
most interested. It seems to be aligned fairly well, but there is no
doubt room to do a better job. I might buy a couple of machinist's
jacks in hopes of holding it in place with the adpater loose. That
would hopefully allow me to fiddle until the gears work as smoothly as
possible, and then tighten the bolts w/o disturbing it. Comments?
Better ideas?



I was envisioning a longitudinal indicator too. Is there any particular
reason you do not use one in that direction?
Thanks!
Bill

=============
Did not need micrometer location accuracy along that axis [X]
[cutting slot] so did not put an indicator there. I have never
had occassion to machine anything that required micrometer
accuracy on all three axis at the same time.

Fair enough.


If you think you may be doing this sort of thing extensively you
may want to consider fabricating dial indicator holders and
possibly modifying your table/slide [drill & tap] to mount the
indicators/holders.

It was _not_ (!!!!) me, REALLY One of the old war stories in my
general niche is that some well meaning dude took a drill to a high tech
anesthesia machine. He wanted to mount something - simple, right? What
he didn't know is that machine in question had manifolds integrated with
the case. I did not hear whether the entire machine was scrapped, but
it seems likely.

First, I will start with a mighty mag to see how it works out. Looking
at the machine with your comments in mind, I might see how to do it w/o
drilling. Before I drill, I would want to have evidence that the
machine is flawed. So far, I still believe it is more accurate than its
operator.

Thanks!!!!

Bill

snip
On Tue, 20 Dec 2005 20:24:58 GMT, Bill Schwab
wrote:
First, I will start with a mighty mag to see how it works out. Looking
at the machine with your comments in mind, I might see how to do it w/o
drilling. Before I drill, I would want to have evidence that the
machine is flawed. So far, I still believe it is more accurate than its
operator.
Thanks!!!!
Bill
--------------
They generally are .... Main reason for using the dial indicator
is easier reading [which becomes more important the older you
get] and elimination of the backlash problem. One concern on
metric machines is when they kept the metric feed screw [or use
someting other than a 10 or 20 TPI] and simply used a .001 inch
graduation collar to produce an inch machine. Works fine for
small moves but is a problem when you go "across" the division
lines by moving more than one lead.

Uncle George