Bought a set of cheap metric taps and associated tapping drills on
EBAY, tried one out tonight. Drilling the end of a 12mm sq aluminium
rod for a 4mm bolt,, set up in the 4 jaw at centre, 3.3mm is drill in
chuck in tailstock.

Started drilling - fine for about half inch, nice clean equal length
swarf spiraling out of the hole (using WD40 as lubricant) - but
then...

Got in a bit more, with frequent backing out to clear rubbish, and it
stopped cutting - more like rubbing its way into the hole, fine,
almost powder round the bit...this causes the hole to widen out, it
grabbed, , the drill chuck taper started spinning in the tailstock
(not good) - still got enough to tap (its not critical, this time -
support rails for a transmitter cabinet I am building).

So, what gives - tried other tapping lubricants, no luck. Varied
speed, same results.

The start of the drill hole shows that the drill is sharp, so why does
it go weird as it gets further into the hole? - anything I should be
doing, or is it just this particular drill bit....

Andrew VK3BFA.

On Nov 7, 10:49 pm, wrote:
Bought a set of cheap metric taps and associated tapping drills on
EBAY, tried one out tonight. Drilling the end of a 12mm sq aluminium
rod for a 4mm bolt,, set up in the 4 jaw at centre, 3.3mm is drill in
chuck in tailstock.

Started drilling - fine for about half inch, nice clean equal length
swarf spiraling out of the hole (using WD40 as lubricant) - but
then...

Got in a bit more, with frequent backing out to clear rubbish, and it
stopped cutting - more like rubbing its way into the hole, fine,
almost powder round the bit...this causes the hole to widen out, it
grabbed, , the drill chuck taper started spinning in the tailstock
(not good) - still got enough to tap (its not critical, this time -
support rails for a transmitter cabinet I am building).

So, what gives - tried other tapping lubricants, no luck. Varied
speed, same results.

The start of the drill hole shows that the drill is sharp, so why does
it go weird as it gets further into the hole? - anything I should be
doing, or is it just this particular drill bit....

Andrew VK3BFA.

Oh, forgot - tried 3 times, still does the same behavior each time, so
its not the bit going blunt real quick...

Andrew VK3BFA.

On Wed, 07 Nov 2007 03:50:41 -0800, wrote:

On Nov 7, 10:49 pm, wrote:
Bought a set of cheap metric taps and associated tapping drills on
EBAY, tried one out tonight. Drilling the end of a 12mm sq aluminium
rod for a 4mm bolt,, set up in the 4 jaw at centre, 3.3mm is drill in
chuck in tailstock.

Started drilling - fine for about half inch, nice clean equal length
swarf spiraling out of the hole (using WD40 as lubricant) - but
then...

Got in a bit more, with frequent backing out to clear rubbish, and it
stopped cutting - more like rubbing its way into the hole, fine,
almost powder round the bit...this causes the hole to widen out, it
grabbed, , the drill chuck taper started spinning in the tailstock
(not good) - still got enough to tap (its not critical, this time -
support rails for a transmitter cabinet I am building).

So, what gives - tried other tapping lubricants, no luck. Varied
speed, same results.

The start of the drill hole shows that the drill is sharp, so why does
it go weird as it gets further into the hole? - anything I should be
doing, or is it just this particular drill bit....

Andrew VK3BFA.

Oh, forgot - tried 3 times, still does the same behavior each time, so
its not the bit going blunt real quick...

Andrew VK3BFA.


HOw fast are you turning? You should be turning as fast as you can
go.

Hole widened out? Check the offset of your tailstock. Sounds like a
misalignment of spindle and tailstock. That powder sounds like you are
pulling swarf off the sides of the hole rather than down the center.
When a bit is running out of line, aluminium stringers can get trapped
on the near side, wad up and then jam.

When you start the hole, doe the chip curl come out even from each
flute? If only one flute is producing..you either have a bit with a
dull flute on one side or the other, or its Way out of center

Gunner

Political Correctness is a doctrine fostered by a delusional,
illogical liberal minority, and rabidly promoted by an
unscrupulous mainstream media, which holds forth the
proposition that it is entirely possible to pick up a turd by the clean end.

On Nov 7, 11:18 pm, Gunner Asch wrote:
On Wed, 07 Nov 2007 03:50:41 -0800, wrote:
On Nov 7, 10:49 pm, wrote:
Bought a set of cheap metric taps and associated tapping drills on
EBAY, tried one out tonight. Drilling the end of a 12mm sq aluminium
rod for a 4mm bolt,, set up in the 4 jaw at centre, 3.3mm is drill in
chuck in tailstock.

Started drilling - fine for about half inch, nice clean equal length
swarf spiraling out of the hole (using WD40 as lubricant) - but
then...

Got in a bit more, with frequent backing out to clear rubbish, and it
stopped cutting - more like rubbing its way into the hole, fine,
almost powder round the bit...this causes the hole to widen out, it
grabbed, , the drill chuck taper started spinning in the tailstock
(not good) - still got enough to tap (its not critical, this time -
support rails for a transmitter cabinet I am building).

So, what gives - tried other tapping lubricants, no luck. Varied
speed, same results.

The start of the drill hole shows that the drill is sharp, so why does
it go weird as it gets further into the hole? - anything I should be
doing, or is it just this particular drill bit....

Andrew VK3BFA.

Oh, forgot - tried 3 times, still does the same behavior each time, so
its not the bit going blunt real quick...

Andrew VK3BFA.

HOw fast are you turning? You should be turning as fast as you can
go.

Hole widened out? Check the offset of your tailstock. Sounds like a
misalignment of spindle and tailstock. That powder sounds like you are
pulling swarf off the sides of the hole rather than down the center.
When a bit is running out of line, aluminium stringers can get trapped
on the near side, wad up and then jam.

When you start the hole, doe the chip curl come out even from each
flute? If only one flute is producing..you either have a bit with a
dull flute on one side or the other, or its Way out of center

Gunner

Political Correctness is a doctrine fostered by a delusional,
illogical liberal minority, and rabidly promoted by an
unscrupulous mainstream media, which holds forth the
proposition that it is entirely possible to pick up a turd by the clean end.

Thanks Gunner - its 11.35pm here, so will check out your suggestions
tomorrow...

Andrew VK3BFA.

wrote:

Oh, forgot - tried 3 times, still does the same behavior each time, so
its not the bit going blunt real quick...

That is funny, isn't it? :-)
When you retract the drill, clean, lubricate and then continue to drill. How
do the chips come out? Dust?
If it's not dust (at least the very first 2mm), then the flutes have to be
the worst ever made in China. Rough like a sanding paper. Al needs smooooth
flutes.

If it is dust from the very start on, then ... ummm ... 3.3mm 12mm deep? Not
so much a wonder that the chips break. If the diameter is OK ignore it or
buy a drill for Al with ground flutes and not forged ones.


Nick
--
The lowcost-DRO:
http://www.yadro.de

wrote:

Bought a set of cheap metric taps and associated tapping drills

Given that they are probably made in China with price over
quality, I would double check the diameter at several points
down the length. I would not be surprised if it has a gentle
taper....


Jon

Thanks Gunner - its 11.35pm here, so will check out your suggestions
tomorrow...

What Gunner said, and more.

Looks like 9230 (Nine Thousand Two Hundred Thirty) RPM is nominal for a
two-flute 3.3 mm HSS drill into aluminum. (But read the last paragraph!)

RPM = (Teeth * CS)/D

Where (In Olde Englishe Units):
Teeth = Number of cutting teeth per tool
CS = Cutting speed for Aluminum ~ 600 Surface Feet Per Minute
D = Diameter of Drill 3.3 mm ~ 0.13"

9230 RPM =(2*600)/0.13"

What this means to you:
Whatever speed you choose, you must not waste any time backing the drill
out of the hole. If you slowly retract
the drill, it will spend many revolutions riding inside the cone it made
in the material, causing it to work - harden your workpiece. Blowing
through that hardened material on the way back in can be challenging.

--Winston

Winston wrote:

RPM = (Teeth * CS)/D

What funny formula did you find here?
Cutting speed has nothing to do with number of teeth/flutes.

If you slowly retract
the drill, it will spend many revolutions riding inside the cone it made
in the material, causing it to work - harden your workpiece.

Ouch! Burn that textbook where you have that nonsense from. It is really
hard to work-harden Al (pun intended) and if, you will only succeed when
cutting and not when retracting.


Nick
--
The lowcost-DRO:
http://www.yadro.de

On Thu, 08 Nov 2007 01:36:24 +0100, Nick Mueller
wrote:

Winston wrote:

RPM = (Teeth * CS)/D

What funny formula did you find here?
Cutting speed has nothing to do with number of teeth/flutes.

If you slowly retract
the drill, it will spend many revolutions riding inside the cone it made
in the material, causing it to work - harden your workpiece.

Ouch! Burn that textbook where you have that nonsense from. It is really
hard to work-harden Al (pun intended) and if, you will only succeed when
cutting and not when retracting.


Nick

Actually it is quite easy to work harden aluminum, but work hardened
aluminum is still extremely soft relative to a HSS tool.


Bruce-in-Bangkok
(Note:displayed e-mail
address is a spam trap)

Nick Mueller wrote:
Winston wrote:


RPM = (Teeth * CS)/D


What funny formula did you find here?
Cutting speed has nothing to do with number of teeth/flutes.

Rather, that's RPM=(4* CS)/D

If you slowly retract
the drill, it will spend many revolutions riding inside the cone it made
in the material, causing it to work - harden your workpiece.


Ouch! Burn that textbook where you have that nonsense from. It is really
hard to work-harden Al (pun intended) and if, you will only succeed when
cutting and not when retracting.

When cutting, the edge of the tool is under the surface of the material,
yes? If the edge of the tool is merely rubbing against the material,
friction will raise the temperature quite enough to make a subsequent
re-start difficult. It works that way for me anyway.

--Winston

Bruce in Bangkok wrote:

On Thu, 08 Nov 2007 01:36:24 +0100, Nick Mueller
wrote:


Winston wrote:


RPM = (Teeth * CS)/D

What funny formula did you find here?
Cutting speed has nothing to do with number of teeth/flutes.


If you slowly retract
the drill, it will spend many revolutions riding inside the cone it made
in the material, causing it to work - harden your workpiece.

Ouch! Burn that textbook where you have that nonsense from. It is really
hard to work-harden Al (pun intended) and if, you will only succeed when
cutting and not when retracting.


Nick


Actually it is quite easy to work harden aluminum, but work hardened
aluminum is still extremely soft relative to a HSS tool.

Then we should try to explain why pecking a hole in aluminum at low RPM
and no lubrication should cause cutting to fail at the start of the
second 'peck'. I conjecture that friction may be causing the gummy
aluminum to stick to the cutting edges of the drill, ruining the bits
ability to get into the parent material. It may not be 'work hardening'
per se. Instead of a pair of nice smooth stringy chips, we get powder.

Is the moral of the story to always use fluid when pecking aluminum?


--Winston

On Nov 7, 11:18 pm, Gunner Asch wrote:
On Wed, 07 Nov 2007 03:50:41 -0800, wrote:
On Nov 7, 10:49 pm, wrote:
Bought a set of cheap metric taps and associated tapping drills on
EBAY, tried one out tonight. Drilling the end of a 12mm sq aluminium
rod for a 4mm bolt,, set up in the 4 jaw at centre, 3.3mm is drill in
chuck in tailstock.

Started drilling - fine for about half inch, nice clean equal length
swarf spiraling out of the hole (using WD40 as lubricant) - but
then...

Got in a bit more, with frequent backing out to clear rubbish, and it
stopped cutting - more like rubbing its way into the hole, fine,
almost powder round the bit...this causes the hole to widen out, it
grabbed, , the drill chuck taper started spinning in the tailstock
(not good) - still got enough to tap (its not critical, this time -
support rails for a transmitter cabinet I am building).

So, what gives - tried other tapping lubricants, no luck. Varied
speed, same results.

The start of the drill hole shows that the drill is sharp, so why does
it go weird as it gets further into the hole? - anything I should be
doing, or is it just this particular drill bit....

Andrew VK3BFA.

Oh, forgot - tried 3 times, still does the same behavior each time, so
its not the bit going blunt real quick...

Andrew VK3BFA.

HOw fast are you turning? You should be turning as fast as you can
go.

Hole widened out? Check the offset of your tailstock. Sounds like a
misalignment of spindle and tailstock. That powder sounds like you are
pulling swarf off the sides of the hole rather than down the center.
When a bit is running out of line, aluminium stringers can get trapped
on the near side, wad up and then jam.

When you start the hole, doe the chip curl come out even from each
flute? If only one flute is producing..you either have a bit with a
dull flute on one side or the other, or its Way out of center

Gunner

Political Correctness is a doctrine fostered by a delusional,
illogical liberal minority, and rabidly promoted by an
unscrupulous mainstream media, which holds forth the
proposition that it is entirely possible to pick up a turd by the clean end.

**** **** **** fuvk **** **** ****........

A lousy day, and it gets worse.......

OK. After getting a late start due SWMBO nefarious commitments, did
the following.

1.Checked tailstock alignment - was out 5 thou inch, so corrected
that. Interestingly, had to make allowances for the tailstock clamp
bolt being tightened up, so it took a while to get it to slighly under
1 thou inch in 2 feet.

2. Checked drill bit diameter - measured 3.28 mm at cutting end, then
3.25 the rest of it.

3.So, tried again. Still the same. Started cutting out fine, equal
length spirals of swarf from drill, but once it got to about 12mm,
then the powder problem/wouldn't cut thing started again.
To check, tried with a known good quality 3mm drill bit - same
results.

(This was after a lot of stuffing around - the 3 jaw chuck is sooo
cheap, had to spend time filing the jaws and the slots to get the jaws
to run up and down without binding. Then, the jaws are held to the
backplate with big nuts held by a wave washer - theres a fraction of a
turn between tight and too tight to move the jaw. Plus, the chuck key
keeps jamming on the adjuster...

The bloody morse taper shank on the drill chuck on the tailstock end -
the tang wont/cant/doesn't feel like/ locking into the barrel, so it
starts too spin if it encounters much torque at all.....)

Getting really ****ed off by this stage.

Tried very fast RPM - it was terrifying, thought the thing was going
to take off, and with the dubious lock nuts on the back of the 4
jaw...besides, didn't make any difference, except it all happened
quicker.

So. Tried NO LUBRICANT - strangely, marginally better results. Of
course, the drill chuck came loose from the tailstock (again!) and I
had to pull it out by hand twisting and cursing.

Sooooooooo....(wait for it....)

Decided to make the hole a bit deeper so to be sure of getting enpough
depth for the bolts I was using.

Set up, switched on.

Lathe motor died. (hence the opening lines of this post...)

Horrible growling noises, runs at a few rpm only, can be stalled by
hand......

Stuff this. I wanna good lathe like the ones at school........, one I
can USE rather than have to stuff around with endlessly.

Anyone in Melbourne, Australia got a decent 2nd hand one going for a
reasonable rate?

Andrew VK3BFA.

wrote:

2. Checked drill bit diameter - measured 3.28 mm at cutting end, then
3.25 the rest of it.

That is right and normal and according to specs. Drill bits *may* have a
slight taper (small end at the shaft). IIRC something around 1%.


Nick
--
The lowcost-DRO:
http://www.yadro.de

Winston wrote:

What funny formula did you find here?
Cutting speed has nothing to do with number of teeth/flutes.

Rather, that's RPM=(4* CS)/D

I expect to find Pi in a formula that has to do with a circle.


Nick
--
The lowcost-DRO:
http://www.yadro.de

Nick Mueller wrote:
Winston wrote:


What funny formula did you find here?
Cutting speed has nothing to do with number of teeth/flutes.

Rather, that's RPM=(4* CS)/D


I expect to find Pi in a formula that has to do with a circle.

See "D" for diameter.

--Winston

On Wed, 07 Nov 2007 23:00:57 -0800, with neither quill nor qualm,
quickly quoth:

On Nov 7, 11:18 pm, Gunner Asch wrote:
On Wed, 07 Nov 2007 03:50:41 -0800, wrote:
On Nov 7, 10:49 pm, wrote:
Bought a set of cheap metric taps and associated tapping drills on
EBAY, tried one out tonight. Drilling the end of a 12mm sq aluminium
rod for a 4mm bolt,, set up in the 4 jaw at centre, 3.3mm is drill in
chuck in tailstock.

Started drilling - fine for about half inch, nice clean equal length
swarf spiraling out of the hole (using WD40 as lubricant) - but
then...

Got in a bit more, with frequent backing out to clear rubbish, and it
stopped cutting - more like rubbing its way into the hole, fine,
almost powder round the bit...this causes the hole to widen out, it
grabbed, , the drill chuck taper started spinning in the tailstock
(not good) - still got enough to tap (its not critical, this time -
support rails for a transmitter cabinet I am building).

So, what gives - tried other tapping lubricants, no luck. Varied
speed, same results.

The start of the drill hole shows that the drill is sharp, so why does
it go weird as it gets further into the hole? - anything I should be
doing, or is it just this particular drill bit....

Andrew VK3BFA.

Oh, forgot - tried 3 times, still does the same behavior each time, so
its not the bit going blunt real quick...

Andrew VK3BFA.

HOw fast are you turning? You should be turning as fast as you can
go.

Hole widened out? Check the offset of your tailstock. Sounds like a
misalignment of spindle and tailstock. That powder sounds like you are
pulling swarf off the sides of the hole rather than down the center.
When a bit is running out of line, aluminium stringers can get trapped
on the near side, wad up and then jam.

When you start the hole, doe the chip curl come out even from each
flute? If only one flute is producing..you either have a bit with a
dull flute on one side or the other, or its Way out of center

Gunner

Political Correctness is a doctrine fostered by a delusional,
illogical liberal minority, and rabidly promoted by an
unscrupulous mainstream media, which holds forth the
proposition that it is entirely possible to pick up a turd by the clean end.

**** **** **** fuvk **** **** ****........

A lousy day, and it gets worse.......

--snip of bad one--

I had one of those days yesterday, too. I'm doing a teensy kitchen
(6x6') remodel for clients. I cut the wallboard out, drilled 4 corner
holes, and felt the two spaces for existing wiring before putting the
sawzall to the outside. Halfway through, I got an extremely large arc
and there was an inch of teeth missing from the blade. I ran inside to
see WTF and found that, despite my checking both holes, I missed the
220v 4-wire cable for the well pump. My saw cut through one phase into
the next, so it was a full 50A arc. Next time, I scissor through the
damned insulation, pull it all out, and eyeball the opening for
wiring. I proved to myself that I can miss it with my fingers. sigh
They called an electrician and with me helping, he was out of there in
30 minutes. His bill was "only" $89 and change.

But it was a good day. It didn't hurt the sawzall, didn't start a
fire, and didn't kill me.

Nexxxxxxxxt!


-----------------------------------------------------------------
When I die, I'm leaving my body to science fiction. --Steven Wright
----------------------------

Winston wrote:
Nick Mueller wrote:
Winston wrote:


What funny formula did you find here?
Cutting speed has nothing to do with number of teeth/flutes.

Rather, that's RPM=(4* CS)/D


I expect to find Pi in a formula that has to do with a circle.

See "D" for diameter.

Actually, it's PI * CS / (12 * D), the 12 being inches-to-feet
conversion factor. PI/12 is rounded to 4, giving 4*CS / D.

Bob

On Nov 8, 2:00 am, wrote:

1.Checked tailstock alignment - was out 5 thou inch, so corrected
that. Interestingly, had to make allowances for the tailstock clamp
bolt being tightened up, so it took a while to get it to slighly under
1 thou inch in 2 feet.

Andrew VK3BFA

The tailstock might be out of alignment vertically if it was
originally from another lathe.

Jim Wilkins KB1DAL

Bob Engelhardt wrote:
Actually, it's PI * CS / (12 * D), the 12 being inches-to-feet
conversion factor. PI/12 is rounded to 4, giving 4*CS / D.

Boy, I screwed that up. Talk about brain farts, that one stinks!

It's: CS = PI * D / 12 (ft/rev) * RPM; ft/min
or
RPM = CS * 12/(PI *D), round 12/PI to 4, giving

RPM = 4 * CS / D

I'll be quiet now,
Bob

Bob Engelhardt wrote:

Actually, it's PI * CS / (12 * D)

Did you visit the same school as Winston did? :-)


Nick
--
The lowcost-DRO:
http://www.yadro.de

On Wed, 07 Nov 2007 23:00:57 -0800, wrote:



The bloody morse taper shank on the drill chuck on the tailstock end -
the tang wont/cant/doesn't feel like/ locking into the barrel, so it
starts too spin if it encounters much torque at all.....)



Stop right there!

Wipe the inside of the taper out wit a clean finger and find any swarf down
the hole. Feel for damage on taper and on chuck shank. If you find damage on
the shank, gently stone or file it out. if you find damage in the tailstock
taper, ream it clean. if you cant find the damage, lightly blue the shank and
insert it gently in the tailstock. twist a few degrees and withdraw. Find
where the problem is and correct it.

Once you've done that, you can start looking for problems with drilling...



Mark Rand
RTFM

On Nov 9, 6:31 am, Mark Rand wrote:
On Wed, 07 Nov 2007 23:00:57 -0800, wrote:

The bloody morse taper shank on the drill chuck on the tailstock end -
the tang wont/cant/doesn't feel like/ locking into the barrel, so it
starts too spin if it encounters much torque at all.....)

Stop right there!

Wipe the inside of the taper out wit a clean finger and find any swarf down
the hole. Feel for damage on taper and on chuck shank. If you find damage on
the shank, gently stone or file it out. if you find damage in the tailstock
taper, ream it clean. if you cant find the damage, lightly blue the shank and
insert it gently in the tailstock. twist a few degrees and withdraw. Find
where the problem is and correct it.

Once you've done that, you can start looking for problems with drilling...

Mark Rand
RTFM

OK. Points noted. I have checked the inside of the taper for rubbish,
its ok (that was Lesson 1 at school) - likewise the taper on the chuck
shank adapter (MT2).......I haven't checked the actual dimensions of
the adapter, just assumed it was in specification - it has a tang on
the end, which SHOULD lock into a groove at the end of the tailstock
ram - at least, thats what its for, and the Colchesters at school work
that way. As you suggest, will blue it and check fit - but I dont see
that it will make any difference, the problem is that the tang isn't
locking into anything. Its not a problem for the live center, it has a
threaded hole for a drawbar, but its taper shaft will never rotate
anyway - Anyone has a 9 by 20, experienced the same problem, or is
something crook with mine?

Its just another thing I need to figure out - still have the drilling
problem, and need to fix the motor (first thing to do is physically
manhandle the bloody thing into a position where I can actually get to
the motor, check start/run caps etc...)

And I have calmed down a bit too - sorry about the blue collar
language - I WILL get on top of this thing, in time. Trouble is, I
want to make things with it, rather than be sorting out the machine
issues......

Andrew VK3BFA.

wrote:
On Nov 9, 6:31 am, Mark Rand wrote:
On Wed, 07 Nov 2007 23:00:57 -0800, wrote:

The bloody morse taper shank on the drill chuck on the tailstock end - the
tang wont/cant/doesn't feel like/ locking into the barrel, so it starts too
spin if it encounters much torque at all.....)
Stop right there!

Wipe the inside of the taper out wit a clean finger and find any swarf down the
hole. Feel for damage on taper and on chuck shank. If you find damage on the
shank, gently stone or file it out. if you find damage in the tailstock taper,
ream it clean. if you cant find the damage, lightly blue the shank and insert it
gently in the tailstock. twist a few degrees and withdraw. Find where the
problem is and correct it.

Once you've done that, you can start looking for problems with drilling...

Mark Rand RTFM

OK. Points noted. I have checked the inside of the taper for rubbish, its ok (that
was Lesson 1 at school) - likewise the taper on the chuck shank adapter
(MT2).......I haven't checked the actual dimensions of the adapter, just assumed
it was in specification - it has a tang on the end, which SHOULD lock into a
groove at the end of the tailstock ram - at least, thats what its for, and the
Colchesters at school work that way. As you suggest, will blue it and check fit -
but I dont see that it will make any difference, the problem is that the tang
isn't locking into anything. Its not a problem for the live center, it has a
threaded hole for a drawbar, but its taper shaft will never rotate anyway - Anyone
has a 9 by 20, experienced the same problem, or is something crook with mine?

Its just another thing I need to figure out - still have the drilling problem, and
need to fix the motor (first thing to do is physically manhandle the bloody thing
into a position where I can actually get to the motor, check start/run caps
etc...)

And I have calmed down a bit too - sorry about the blue collar language - I WILL
get on top of this thing, in time. Trouble is, I want to make things with it,
rather than be sorting out the machine issues......

Andrew VK3BFA.

Is it possible that you are exceeding the working range of your tailstock ram or
that the problem is some form of obstruction within the thread of the ram.


I looked up the tailstock specs on a HF 9 by 20 and found:
Tailstock:
Spindle diameter: 1''
Spindle travel: 1-5/8''
Spindle taper: MT-2


1-5/8ths is pretty short and anyone could run out of travel pretty easily.

I'm a bit spoiled with larger lathes. 1-5/8'' is difficult to work with.

"Winston" wrote in message
news:nsrYi.4377$m44.2230@trnddc06...

snip------
What this means to you:
Whatever speed you choose, you must not waste any time backing the drill
out of the hole. If you slowly retract
the drill, it will spend many revolutions riding inside the cone it made
in the material, causing it to work - harden your workpiece.

Not in aluminum. Work hardening is a non-issue.

Backing the drill is all important once considerable depth is achieved.
Chips often pack in the flutes to the point of binding the drill in the hole
otherwise.

Harold






Blowing
through that hardened material on the way back in can be challenging.

--Winston

wrote in message
oups.com...
snip----

The start of the drill hole shows that the drill is sharp, so why does
it go weird as it gets further into the hole? - anything I should be
doing, or is it just this particular drill bit....

Andrew VK3BFA.


I suggest you measure the drill at the margin, to see if it is tapered the
wrong direction. Drills are made with a slight taper, diminishing is size
from the cutting end towards the shank, a thou or slightly more, so the
drill won't drag in the hole created, assuming it cuts size. If the drill
is tapered the wrong way, it's possible you're creating a hole that is ever
increasing in tool contact, finally overcoming the tailstock taper's ability
to hold the drill.

Use a micrometer to measure the margins, which should be diametrically
opposed, and circle ground, so you have a decent surface to measure.

Harold

Harold and Susan Vordos wrote:

"Winston" wrote in message
news:nsrYi.4377$m44.2230@trnddc06...

snip------

What this means to you:
Whatever speed you choose, you must not waste any time backing the drill
out of the hole. If you slowly retract
the drill, it will spend many revolutions riding inside the cone it made
in the material, causing it to work - harden your workpiece.


Not in aluminum. Work hardening is a non-issue.

Backing the drill is all important once considerable depth is achieved.
Chips often pack in the flutes to the point of binding the drill in the hole
otherwise.

Harold

I'm familiar with that. But I'm also familiar with the effect the
original poster mentioned, (backing out the drill then having it bind in
a deepish hole in aluminum at the start of the second 'peck').

--Winston

According to :
On Nov 9, 6:31 am, Mark Rand wrote:
On Wed, 07 Nov 2007 23:00:57 -0800, wrote:

The bloody morse taper shank on the drill chuck on the tailstock end -
the tang wont/cant/doesn't feel like/ locking into the barrel, so it
starts too spin if it encounters much torque at all.....)

[ ... ]

OK. Points noted. I have checked the inside of the taper for rubbish,
its ok (that was Lesson 1 at school) - likewise the taper on the chuck
shank adapter (MT2).......I haven't checked the actual dimensions of
the adapter, just assumed it was in specification - it has a tang on
the end, which SHOULD lock into a groove at the end of the tailstock
ram - at least, thats what its for, and the Colchesters at school work
that way.

The purpose of the tang is *not* to lock the shaft, but to
provide something for the extraction key to work on. With lathes, quite
often, this function is purely handled by the end of the leadscrew when
you crank the ram far enough back. So -those will not have a slot for
the tang.

The taper is held in *only* by the fit in the female taper of
the tailstock ram. You need to clean the surfaces as above -- and
(assuming a good taper on both parts) snap it into place so you can't
pull it out by hand -- you need to use the key (if there is a slot for
it) or the end of the handwheel's leadscrew to knock it out.

And -- note that the arbor is held into the chuck by another
taper -- *without* a key tang at all. For that (when fitting a new
arbor) place some pine 2x4 on the concrete floor, put the arbor lightly
into the socket in the chuck. and bring it down, arbor end first, onto
the 2x4, so the weight (and inertia) of the chuck will drive it onto the
Jacobs taper end of the arbor. (To remove, you need some Jacobs taper
wedges for the size of Jacobs taper you have. They are inexpensive, but
very useful to have around.

If the fit is not right -- you do need to get an appropriate
Morse taper reamer to clean up the inside of the tailstock ram. And as
for the OD of the chuck's arbor -- you can file or stone off dings which
produce problems -- but if the taper is not a proper match for the
standard, your best bet is to replace the arbor.

As you suggest, will blue it and check fit - but I dont see
that it will make any difference, the problem is that the tang isn't
locking into anything. Its not a problem for the live center, it has a
threaded hole for a drawbar,

How are you going to get a drawbar to it through the leadscrew
of the tailstock? I've gotten an interchangeable point live center with
such threading -- and I had to machine a brass plug to fit into it to
provide a surface for the leadscrew to bump the taper out of the ram.
Luckily, my Clausing has a slot for the Morse taper key, so I could get
the arbor out without having to remove the ram totally and drive through
the hole where the leadscrew was. But that key slot is a pain other
times, because it means that I have to orient the tang properly before
slapping the arbor/chuck into place.

but its taper shaft will never rotate
anyway - Anyone has a 9 by 20, experienced the same problem, or is
something crook with mine?

I don't have the 9x20 -- but from the description of your 4-jaw
chuck -- it has serious problems. The first thing would be to get a
proper chuck for it -- what you have is a woodworking 4-jaw chuck. And
*do* check the taper fit. Ideally, with a set of Morse taper gauges for
the taper you have -- a male one for checking the socket, and a female
one for checking the arbor. And *don't* slap those in -- just lightly
put in the (very lightly) blued part, rotate it a little, and pull it
back out to check the areas which have been cleared of bluing compound.

Oh yes -- also expect to have blue hands for a while after this. :-)
This is the blue spotting compound used when scraping in a part, not the
blue layout die. :-)

Its just another thing I need to figure out - still have the drilling
problem, and need to fix the motor (first thing to do is physically
manhandle the bloody thing into a position where I can actually get to
the motor, check start/run caps etc...)

I would suggest the start cap as the first thing likely. But
the motors on these import machines have a bad reputation anyway, so you
may have a shorted turn in the winding or something like that -- which
you should look upon as an excuse to get a better motor.

And I have calmed down a bit too - sorry about the blue collar
language -

Frustration can lead to that.

I WILL get on top of this thing, in time. Trouble is, I
want to make things with it, rather than be sorting out the machine
issues......

Understood. I think that you now see why some people here
suggest a used US made machine, instead of an import one.

BTW Is it possible that your problem with drilling the aluminum is
a result of an inconsistent alloy as you go deeper? Are you
cutting lengths from rod stock and drilling into the ends, or
are you cutting and drilling from the side, so you go through
the same layers at the same depth?

Can you move a sample over to a drill press and see what
behavior you get there?

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 ---

wrote:

Trouble is, I
want to make things with it, rather than be sorting out the machine
issues......

Buy a new one! And you'll have to sort out new problems. :-)


Nick
--
The lowcost-DRO:
http://www.yadro.de

"Winston" wrote in message Harold and Susan Vordos
wrote:

Backing the drill is all important once considerable
depth is achieved.
Chips often pack in the flutes to the point of binding
the drill in the hole
otherwise.

Harold

I'm familiar with that. But I'm also familiar with the
effect the
original poster mentioned, (backing out the drill then
having it bind in
a deepish hole in aluminum at the start of the second
'peck').

--Winston

Perhaps not all the chips were removed from the hole when
backing out and when going back in the drill is sitting on
top
of a pile of loose swarf at the bottom of the hole.
phil kangas



--
Posted via a free Usenet account from http://www.teranews.com

Bob Engelhardt wrote:
Bob Engelhardt wrote:
Actually, it's PI * CS / (12 * D), the 12 being inches-to-feet

conversion factor. PI/12 is rounded to 4, giving 4*CS / D.


Boy, I screwed that up. Talk about brain farts, that one stinks!

It's: CS = PI * D / 12 (ft/rev) * RPM; ft/min
or
RPM = CS * 12/(PI *D), round 12/PI to 4, giving

RPM = 4 * CS / D

I wondered what the '4' did!
Thanks for the explaination!

--Winston

Phil Kangas wrote:

"Winston" wrote in message Harold and Susan Vordos
wrote:

(...)
I'm familiar with that. But I'm also familiar with the

effect the

original poster mentioned, (backing out the drill then

having it bind in

a deepish hole in aluminum at the start of the second

'peck').

--Winston


Perhaps not all the chips were removed from the hole when
backing out and when going back in the drill is sitting on
top
of a pile of loose swarf at the bottom of the hole.
phil kangas

That seems highly likely.
Looks like a use for a needle tipped air gun like:
http://www.use-enco.com/CGI/INLMKD?S...01=1&SICOUNT=1

--Winston

Andrew, as someone else has mentioned, the Morse taper arbor should not spin
in the tailstock ram (not ever). That issue should be addressed immediately,
before the ram socket gets messed up.
Checking the dimensions of all of your tooling that has Morse 2 tapers might
reveal that the taper on the drill chuck arbor is bad, a defective part.
Some dye might reveal that the taper is only making contact at the big end.
Replacement is probably the best solution (if the socket in the tailstock
ram is within specification), because damaging the socket taper will affect
all future operations that require the use of the tailstock.
If it turns out that the tailstock ram socket is out-of-spec, maybe the
dealer will provide a new replacement.

The male and female tapers should be identical, and lock together securely
when the male part is bumped firmly into the socket.
When the tapers lock together, it will normally require a somewhat serious
amount of force to separate them. When the tailstock ram is retracted back
into the tailstock casting (by turning the handwheel), a noticeable pop
should be heard when the tapers unlock. It's a good practice to put one hand
around the tailstock tooling/chuck to prevent the tooling from sliding out
of the tailstock taper, and falling onto the bed ways.
This pop probably won't happen if the male taper is too short. It's the
internal handwheel feedscrew in the tailstock that will contact the small
end of the male taper somewhere near the full retraction of the ram into the
tailstock housing, which begins to apply pressure on the male taper to
release the locking action of the two mated tapers (the male taper of the
tooling, and the female socket taper of the tailstock ram).

If the above action can be visualized, it's easy to "see" that the male
taper will not be ejected if the male section of the tooling taper is too
short. The handwheel feedscrew won't contact the small end of the tooling
taper to eject it.
The open, threaded end of the taper of the live center (that you mentioned
later) should have a plug in it to keep debris out of the hole (and there
might be a small ball bearing in there), and the plug will also insure that
the small end of the tooling male taper will contact the tailstock handwheel
feedscrew upon retraction, enabling the pressure from the feedscrew to eject
the tooling taper.

Your other comments about the wave washers on the back side of the 4-jaw
chuck plate, seem a bit odd. BTW, some 9x20 owners complain about these
chucks being wood lathe chucks, but other than some deburring to remove
sharp edges, mine has worked very well. The spindles in these machines are
fairly light duty, and I wouldn't consider hanging a heavy chuck on them to
be a wise decision.

The washers on my 9x20 4-jaw chuck plate are thick flat washers (I don't
remember changing them, but I might have). I can see that wave washers would
add to your frustration when adjusting the jaws. My preference is to use
hardened flat washers in places where hardware is loosened for adjustments,
as just loosening the hardware enough to let the part (jaws) move, is ideal.
Making adjustments where washers are soft, often results in extra adjustment
steps, since soft washers will allow the hardware to creep or shift as the
fastener is tightened. A nut that only requires a small amount of rotation
to go from fully tight, to not-too-tight-to-adjust is much easier to work
with.
Quality washers that are case hardened and ground flat make machine
adjustments much easier.

For the drilling problem, I'm curious if the part is getting hot, indicating
a lot of friction. If it's just barely warm, it wouldn't be of any concern.
My first plan of action would probably be to rub a stone across the ground
sections of the drill webs, and try it again with a cutting lubricant. I
haven't used WD40 to drill aluminum, although I might've tried a similar
penetrating product, either Pennzoil or STP aerosol penetrant (just to try
it), but I always use a thicker cutting lube.

For clearing the chips out of the hole, a fuzzy pipe cleaner (or a similar
item from a crafts store) will do a fairly good job if used carefully.. oh
sure, with the lathe fully stopped, of course, yep only after the spindle
has come to a complete stop.

I suppose that the motor wasn't hot from the drilling, so it's probably not
destroyed. IIRC, you repair electronic gear, so you'll most likely know what
to do. The start capacitor is in the box with the Fwd-Stop-Rev switch on my
machine. If you haven't aleady checked every electrical connection to make
sure they are secure (including the internal motor connections and the
centrifugal switch contacts), now would be an excellent time to do so.

Since the motors from China are fairly bad as far as reliability goes,
having an extra motor would prepare you for a fault such as winding
insulation breakdown, a badly burned/pitted centrifugal switch or any other
problems associated with the low quality of those motors.
Variable speed is a fantastic feature, it's unimaginable how great it is.

Unfortunately, the 9x20 lathes do require a lot of improvements. Many folks
have referred to them as a kit lathe.
I've spent a considerable amount of time doing numerous improvements to
mine. Even though I was aware of the limitations and flaws from using one of
these lathes in the past, this model is a fairly good purchase for the sale
price that I paid a number of years ago.

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


wrote in message
oups.com...
Bought a set of cheap metric taps and associated tapping drills on
EBAY, tried one out tonight. Drilling the end of a 12mm sq aluminium
rod for a 4mm bolt,, set up in the 4 jaw at centre, 3.3mm is drill in
chuck in tailstock.

Started drilling - fine for about half inch, nice clean equal length
swarf spiraling out of the hole (using WD40 as lubricant) - but
then...

Got in a bit more, with frequent backing out to clear rubbish, and it
stopped cutting - more like rubbing its way into the hole, fine,
almost powder round the bit...this causes the hole to widen out, it
grabbed, , the drill chuck taper started spinning in the tailstock
(not good) - still got enough to tap (its not critical, this time -
support rails for a transmitter cabinet I am building).

So, what gives - tried other tapping lubricants, no luck. Varied
speed, same results.

The start of the drill hole shows that the drill is sharp, so why does
it go weird as it gets further into the hole? - anything I should be
doing, or is it just this particular drill bit....

Andrew VK3BFA.

On Sun, 11 Nov 2007 09:23:08 -0500, "Wild_Bill"
wrote:

Andrew, as someone else has mentioned, the Morse taper arbor should not spin
in the tailstock ram (not ever). That issue should be addressed immediately,
before the ram socket gets messed up.
==========
and if it is messed up or even very dirty, click on
http://www.use-enco.com/CGI/INPDFF?P...MITEM=891-4729
note that these are finishing reamers and are not intended to
remove much material. This should be all finger tip work. Be
sure and use a tap wrench to avoid the off-center/off-axis pull
you get with a crescent wrench. Keep the bore as clean as
possible while reaming. Ream a little, remove the reamer and
clean everything thing up, repeat as required.


Unka' George [George McDuffee]
============
Merchants have no country.
The mere spot they stand on
does not constitute so strong an attachment
as that from which they draw their gains.

Thomas Jefferson (1743-1826),
U.S. president. Letter, 17 March 1814.

On Nov 12, 6:43 am, F. George McDuffee gmcduf...@mcduffee-
associates.us wrote:
On Sun, 11 Nov 2007 09:23:08 -0500, "Wild_Bill"

wrote:
Andrew, as someone else has mentioned, the Morse taper arbor should not spin
in the tailstock ram (not ever). That issue should be addressed immediately,
before the ram socket gets messed up.

==========
and if it is messed up or even very dirty, click onhttp://www.use-enco.com/CGI/INPDFF?PMPAGE=38&PARTPG=INLMK3&PMITEM=891...
note that these are finishing reamers and are not intended to
remove much material. This should be all finger tip work. Be
sure and use a tap wrench to avoid the off-center/off-axis pull
you get with a crescent wrench. Keep the bore as clean as
possible while reaming. Ream a little, remove the reamer and
clean everything thing up, repeat as required.

Unka' George [George McDuffee]
============
Merchants have no country.
The mere spot they stand on
does not constitute so strong an attachment
as that from which they draw their gains.

Thomas Jefferson (1743-1826),
U.S. president. Letter, 17 March 1814.

OK folks - this is getting more and more complicated, all I wanted to
do was drill and tap a few holes!!! - sometimes, the learning curve is
still vertical....

Have fixed the motor problem - had thought it was a faulty cap based
on observations of meter readings from electronic repair. Nope, wasn't
to be - went down to a motor rewind place, they very kindly checked
the cap for me and gave me a tutorial on checking big, high current,
non polarised electrolytics. It checked ok.

Went home, stared at the motor in utter confusion - the designations
on the terminals mean absolutely nothing. But, fortunately, the switch
had a little diagram showing which wires were the windings, - checked
continuity, were ok. There had been no "brown smell" so I knew they
weren't burnt out. Decided to put the caps back in circuit, so I could
remove the whole motor/switchbox/cap assembly to take to the motor
place. Did that, on a whim, switched on - it worked!

I can only surmise there was a open circuit connection in there
somewhere, I had tightened and checked every connection as routine -
hot favourite would be the bullet crimp connectors from the caps to
the motor windings......either that, or its intermittent, and only
time will tell on that one. As a tech, I hate intermittents that might
come back to haunt you.....

The spinning tailstock arbor needs to be checked out and fixed -
thanks for the hints, people, will do asap.

School tomorrow - plan to take in the 4 jaw chuck, set it up on the
Bridgport mill, and clean it up so all working surfaces are parallel.
I am wondering if the jaws are out of square with each other - if this
were so, there would be a bias on the work up/down/sideway/who knows
where and this would explain the strange drill bit behavior - as it
got further into the work, it would be trying to do an arc - hence the
powder, and the thing sticking and spinning the (probably faulty)
drill chuck arbor...anyway, will set it up and check - school has
surface plates and decent instrumentation.

I had had to work on the jaws and the corresponding slots in the face
plate to be able to get smooth sliding of the jaws - as it came from
the factory, it was binding. I did this with a smooth file and have
possibly got a taper in the groove - also, the problem with the lock
nuts on the jaws binding might be the back of the faceplate contact
area being not parallel to the front. The face of the thing is pretty
square to the spindle, so will use that as a reference...

Hopefully, this theory wont crash and burn like mots of my previous
ones - will post results when I get them....

Thanks people for the comments,, observations, and ideas - all
appreciated.

Andrew VK3BFA.

wrote:

I am wondering if the jaws are out of square with each other - if this
were so, there would be a bias on the work up/down/sideway/who knows
where and this would explain the strange drill bit behavior - as it
got further into the work, it would be trying to do an arc

No Sir! It doesn't matter how odd the jaws or the chuck is, the work will
still rotate around the spindle's center line.
Certainly makes a difference when needing to hold something that has to be
coaxial to the spindle. Not in this case.


Nick
--
The lowcost-DRO:
http://www.yadro.de