It's one of those Micro-Mark mini-mills. I'm tired of beating (albeit
with a plastic head mallet) the bejesus out of the DB to loosen the
tapers due to overtightening. Is there a recommended torque for these
things. Thanks.

wrote:
It's one of those Micro-Mark mini-mills. I'm tired of beating (albeit
with a plastic head mallet) the bejesus out of the DB to loosen the
tapers due to overtightening. Is there a recommended torque for these
things. Thanks.

What is the spindle taper and what is the tooling in the spindle ? (I'm
not familiar with that machine.) On my RF45 clone , I have to beat on the
wrench to get the R-8 collets tight enough to hold an end mill without
slipping on heavy cuts .
If you're mounting end milld holders the requirement is going to be
different from using collets to grip an end mill or drill bit .
Yes , I know I should be using end mill holders . Unemployment interrupted
my tool buying frenzy .
--
Snag
every answer
leads to another
question

Terry Coombs wrote:

wrote:
It's one of those Micro-Mark mini-mills. I'm tired of beating (albeit
with a plastic head mallet) the bejesus out of the DB to loosen the
tapers due to overtightening. Is there a recommended torque for these
things. Thanks.

What is the spindle taper and what is the tooling in the spindle ? (I'm
not familiar with that machine.) On my RF45 clone , I have to beat on the
wrench to get the R-8 collets tight enough to hold an end mill without
slipping on heavy cuts .
If you're mounting end milld holders the requirement is going to be
different from using collets to grip an end mill or drill bit .
Yes , I know I should be using end mill holders . Unemployment interrupted
my tool buying frenzy .
--
Snag
every answer
leads to another
question

It's the usual Sieg X2 mini mill. I forget whether they sell the R8 or
MT3 version.

What is the spindle taper and what is the tooling in the spindle ?

MT3. End mill holder and drill chuck tapers. No collets.


On Dec 16, 9:21*pm, "Terry Coombs" wrote:

It's the usual Sieg X2 mini mill. I forget whether they sell the
R8 or MT3 version.

Micro-Mark sells the MT3 variant.


On Dec 16, 9:54*pm, "Pete C." wrote:

wrote:
What is the spindle taper and what is the tooling in the spindle ?

MT3. End mill holder and drill chuck tapers. No collets.


Then I'd suggest it just needs to be tight enough to seat the taper . Get
out the torque wrench and do a few tests ... I know that a drill chuck in
the 3MT tailstock on my lathe will take quite a bit of torque , with no
drawbar at all . Just slid in firmly by hand .
--
Snag
every answer
leads to another
question

Get out the torque wrench and do a few tests

Geez, I was hoping someone had done those tests already. Tried to join
a Yahoo group supposedly devoted to these Sieg Mini-mills only to find
out it's practically dormant. One needs to get permission from the mod
to join and I've been waiting for the last two days.

Anyway, thanks, guess I'll have to find my own settings.


On Dec 17, 9:42*pm, "Terry Coombs" wrote:

I haven't used one of these machines, but I wonder if your collets are
seating properly.
If you start seeing wear marks (changes in the collet surface finish) at the
small end and nowhere else along the collet, the collets or the spindle may
be out of tolerance.

I've never liked rapping on the drawbar to unlock Morse tapers, but it's
been done for decades, so it's an accepted practice, although that practice
did come from machines weighing 1000s of pounds, not light duty benchtop
machines.

When the collets don't seat properly, it may take excessive torque to attain
a good grip on the cutting tool shank. If the morse tapers don't mate nearly
perfectly, some improper wear or distortion is likely to occur.

If you're not able to attain a solid grip on the proper size of cutting
tool, you may be faced with altering the small ends of the collets to reach
the proper gripping force.
If the machine is new, you should probably discuss it with a customer
service technical person for the seller.

A nearly ideal setup might include a lever actuated cam lobe to apply force
to the drawbar end, but this isn't particularly easy to retrofit into an
existing machine design.

Tying to fabricate a big lever-closed clamp-type tool, similar to a engine
head spring compressor doesn't sound like a very easy task either. There
would probably be too much flexing along the length of the tool to create
enough pressure to release the collet.

All that you may be able to do is closely examine the surface finish of the
collets, and feel the inside finish of the spindle with your fingertips to
determine if there are any irregularities.

Another possibility could be mis-marked collets. It's possible that some
collets actual sizes may be incorrectly marked. You could carefully measure
some precision ground parts (unless you have a set of precision plug gages)
to see if other sizes are gripped more securely.

If the proper size isn't being gripped adequately with a reasonable amount
of torque applied (but I don't know what a reasonable amount would be), I'd
think there are likely to be some manufacturing tolerances that were
exceeded (manufacturing defects), either in the spindle or the collets.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


wrote in message
...
It's one of those Micro-Mark mini-mills. I'm tired of beating (albeit
with a plastic head mallet) the bejesus out of the DB to loosen the
tapers due to overtightening. Is there a recommended torque for these
things. Thanks.

but I wonder if your collets are seating properly.

No collets. I don't use it very often and changing tooling is even
less frequent. A consistent minimum acceptable tightening torque will
solve the problem.


On Dec 17, 11:38*pm, "Wild_Bill" wrote:

On Dec 18, 5:42*am, " wrote:
but I wonder if your collets are seating properly.

No collets. I don't use it very often and changing tooling is even
less frequent. A consistent minimum acceptable tightening torque will
solve the problem.

On Dec 17, 11:38*pm, "Wild_Bill" wrote:



My Emco lathe has a milling head unit that uses Morse #2 collets. It
uses a jack bar and a threaded cap to press the collet out. Is your
mill adaptable to something like that?

Paul

Maybe the correct tightening torque would be: not quite a full grunt.

I'm fairly sure that starting at a half of a grunt, then trying a little
more, would do it.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


wrote in message
...
but I wonder if your collets are seating properly.

No collets. I don't use it very often and changing tooling is even
less frequent. A consistent minimum acceptable tightening torque will
solve the problem.


On Dec 17, 11:38 pm, "Wild_Bill" wrote:

Would you happen to know where a detailed picture of the Emco jack bar can
be seen Paul?

I believe any machine that anyone who uses Morse tapers (or any other
locking-type tapers) would benefit greatly with the machine modification of
a lever release for tooling.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


" wrote in message
...
On Dec 18, 5:42 am, " wrote:
but I wonder if your collets are seating properly.

No collets. I don't use it very often and changing tooling is even
less frequent. A consistent minimum acceptable tightening torque will
solve the problem.

On Dec 17, 11:38 pm, "Wild_Bill" wrote:



My Emco lathe has a milling head unit that uses Morse #2 collets. It
uses a jack bar and a threaded cap to press the collet out. Is your
mill adaptable to something like that?

Paul

On Sat, 20 Dec 2008 14:24:05 -0500, the infamous "Wild_Bill"
scrawled the following:

Maybe the correct tightening torque would be: not quite a full grunt.

I'm fairly sure that starting at a half of a grunt, then trying a little
more, would do it.

I learned this wonderful torque technique when I was wrenching for a
living:

Step 1: Tighten slowly until you hear and feel the bolt snap.
Step 2: Now, QUICKLY back it off half a turn.

All done!

--
It is pretty hard to tell what does bring happiness;
poverty and wealth have both failed.
-- Kin Hubbard

The last time I witnessed a friend snap off a bolt, I remarked: Way to go,
tough guy! Have you been workin' out?

Apparently he never learned Step 2.

A mind is a terrible think to waste.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"Larry Jaques" wrote in message
...
On Sat, 20 Dec 2008 14:24:05 -0500, the infamous "Wild_Bill"
scrawled the following:

Maybe the correct tightening torque would be: not quite a full grunt.

I'm fairly sure that starting at a half of a grunt, then trying a little
more, would do it.

I learned this wonderful torque technique when I was wrenching for a
living:

Step 1: Tighten slowly until you hear and feel the bolt snap.
Step 2: Now, QUICKLY back it off half a turn.

All done!

--
It is pretty hard to tell what does bring happiness;
poverty and wealth have both failed.
-- Kin Hubbard

"Wild_Bill" wrote in message
...
Maybe the correct tightening torque would be: not quite a full grunt.

I'm fairly sure that starting at a half of a grunt, then trying a little
more, would do it.

--
WB
.........
metalworking projects
www.kwagmire.com/metal_proj.html


wrote in message
...
but I wonder if your collets are seating properly.

No collets. I don't use it very often and changing tooling is even
less frequent. A consistent minimum acceptable tightening torque will
solve the problem.


On Dec 17, 11:38 pm, "Wild_Bill" wrote:



For us in the metric world ,do you have a metric equivalent of 1 grunt?

"


For us in the metric world ,do you have a metric equivalent of 1 grunt?


1 grunt = 3.67 centiheaves


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

I'm afraid that the metric equivalent of Grunt conversion would involve
calculating fig newton pied du roi (not to be confused with cor du roi),
which I'm unfamiliar with, but I believe is included in the French version
of Machinerys Handbook.

They use it frequently in bicycle design.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html



"Grumpy" wrote in message
. au...

"Wild_Bill" wrote in message
...
Maybe the correct tightening torque would be: not quite a full grunt.

I'm fairly sure that starting at a half of a grunt, then trying a little
more, would do it.

--
WB
.........
metalworking projects
www.kwagmire.com/metal_proj.html


wrote in message
...
but I wonder if your collets are seating properly.

No collets. I don't use it very often and changing tooling is even
less frequent. A consistent minimum acceptable tightening torque will
solve the problem.


On Dec 17, 11:38 pm, "Wild_Bill" wrote:



For us in the metric world ,do you have a metric equivalent of 1 grunt?

The French version unfortunately only contains data on reverse gearing.


"Wild_Bill" wrote in message
...
I'm afraid that the metric equivalent of Grunt conversion would involve
calculating fig newton pied du roi (not to be confused with cor du roi),
which I'm unfamiliar with, but I believe is included in the French version
of Machinerys Handbook.

They use it frequently in bicycle design.

--
WB
.........
metalworking projects
www.kwagmire.com/metal_proj.html



"Grumpy" wrote in message
. au...

"Wild_Bill" wrote in message
...
Maybe the correct tightening torque would be: not quite a full grunt.

I'm fairly sure that starting at a half of a grunt, then trying a little
more, would do it.

--
WB
.........
metalworking projects
www.kwagmire.com/metal_proj.html


wrote in message
...
but I wonder if your collets are seating properly.

No collets. I don't use it very often and changing tooling is even
less frequent. A consistent minimum acceptable tightening torque will
solve the problem.


On Dec 17, 11:38 pm, "Wild_Bill" wrote:



For us in the metric world ,do you have a metric equivalent of 1 grunt?

Keywords:
In article , "Wild_Bill" wrote:
I'm afraid that the metric equivalent of Grunt conversion would involve
calculating fig newton pied du roi (not to be confused with cor du roi),
which I'm unfamiliar with, but I believe is included in the French version
of Machinerys Handbook.

They use it frequently in bicycle design.

I thought the French version was: un grunte

conversion factors: How many oomphs to a grunt?

Doug White

"Bill Noble" wrote in message
...

"


For us in the metric world ,do you have a metric equivalent of 1 grunt?


1 grunt = 3.67 centiheaves

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


Thank you Bill. That was the conversion factor I needed

On Dec 24, 6:17*pm, "Grumpy" wrote:
"Bill Noble" wrote in message

...



"

For us in the metric world ,do you have a metric equivalent of 1 grunt?

1 grunt = 3.67 centiheaves

** Posted fromhttp://www.teranews.com**

Thank you Bill. That was the conversion factor I needed



With a #3MT I'd begin by torquing to 20 ft-lbs, and see how it goes.

Due to size restrictions on my mills I use collets exclusively for
endmills...

My vertical and horizontal mills have #2 and #3 MT respectively, and
the #2 is quite hard to release without the jacking arrangement
supplied by Emco Maier.

Strangely the #3 MT is fairly easy to release, a sharp whack with an
aluminum rapper and it is loose. The #3 MT collets were imports
bought from Busy Bee in Canada. While the tapers are OK some of the
bores were a few thou. oversized. With these I use a sleeve bent up
from appropriate thickness shim stock... The complete set of #3 MT
collets from 1/8" to 3/4" cost less than $80 20-odd years ago and I
didn't quibble about this defect.

The vertical head for the H-mill has a taper I was never able to
identify. The large end is about .025" larger in dia. than a #2 MT
and with a different taper/inch. I tried B&S #7 but no joy. Finally
I machined a batch of collets and shanks from 4140 to solve that
problem. However, this taper is an absolute bear to release. I used
an aluminum rapper and one project where I had to change cutters often
my hand got really sore. Didn't improve the bearings, either; they
now require replacing.

I solved the releasing problem by changing the draw bar, a grade 5
3/8-16UNC hex head bolt 7" long, into a jacking-type draw bar. To do
this it is necessary that the draw bar hole in the spindle be
significantly smaller than the small end dia. of the taper, ie. a step
is required from the bottom dia. of the taper bore to the draw bar
hole. Further, the taper bore must be at least 1/2" deeper than the
reach of the small end of the collet. By fastening a sleeve to the
draw bar such that it bears against this step while unscrewing it, a
jacking action is produced that pushes the collet from the spindle
taper.

Considerable torque is required to push out the collet... I use two
wrenches, one on the draw bar and one on the pre-load adjusting nut
(really two nuts torqued against each other). Of course the cutter
drops out of the collet, but I place a block of wood on the table to
prevent this. This system works quickly and easily and I can
recommend it strongly where it can be retro-fitted.

Wolfgang

With a #3MT I'd begin by torquing to 20 ft-lbs

Finally settled with 5 ft-lbs. Even 10 ft-lbs required too much
whacking to loosen the tapers.

On Dec 24 2008, 7:51*pm, wrote: