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I'm finally up and running with my new 7 X 12 and I am having
a ball! I would first like to thank all the 'old timers' (who are
probably much younger than I) for all the help I have already gotten
from their web sites and from the user groups on the Internet.
Unfortunately for my bank account, I have also found that
milling is almost a necessity in this hobby and I am looking for
alternatives to a milling machine. I discovered Varmit Al's site and
the attachment he designed for a lathe and also found the $129
milling attachment at LittleMachineShop.com. Can anyone offer
comments on this approach to milling on the lathe -- both the pros
and cons?
Many thanks in advance, Clay

Neil,
I don't know if this is exactly what you're looking for, but here are
a couple of URLs that define symbols and standards.





B Flint

--- In 7x12minilathe@..., "Neil" <cobra_neil@a...> wrote:

Would any of you be able to point me to a decent online

tutorial/reference

of CAD drafting standards? Been a looonnnggg time since I've done

any of

this, and I want to re-learn the symbols for finish types, which

lines to

use for what, etc.

Thanks,
-Neil.

Would any of you be able to point me to a decent online tutorial/reference
of CAD drafting standards? Been a looonnnggg time since I've done any of
this, and I want to re-learn the symbols for finish types, which lines to
use for what, etc.

Thanks,
-Neil.

This answers some of the questions, like line styles, etc.
That leaves finish marks as the biggest open question.

Thanks,
-Neil.

Here's a pretty comprehensive article on parting:


20tooling/Parting%20Off/

Roy

--- In 7x12minilathe@..., franksjoy@a... wrote:

I have experienced all the problems with parting and, as one member

said,even

turned the chuck by hand. With my 7X14 the circuit breaker trips as

soon as

the tool hogs. I'm attempting to make a small crankshaft for a

model rotary

engine and there is a strong thrust to the piece as it rotates. I

have fed as

little as .0001 per turn what really amounts to a scrape. Can

anyone explain,

technically, why parting is so difficult?
Max

russlbowen1958 wrote:

I know large machines

BTW, your initial post implied you have some experience with large
lathes. You can make the 7x12 work. I have had fair success at this
with absolutely no prior experience and that is inspite of severe
visual impairment of retina disease.

The concern with the 7x12 mini-lathe should be that, as a previous
reply stated, it is something of a pre-assembled kit which must be
reassembled. These issues are in general concerning backlash
adjustment, gib finish and adjustment, and similar items.

Also see Frank's website www.mini-lathe.com if not already employing
this valuable resource.

Craig

--- In 7x12minilathe@..., franksjoy@a... wrote:
Can anyone explain,

technically, why parting is so difficult?
Max

This isn't the technical explanation, but from what I understand
parting off requires slow speed and heavy feed, so what is needed is
high power. If say if a real 1-hp ac constant speed motor were
available, geared down to the necessary low fpm, and an extremely
sharp tool is in use, and everything is rigid, then one could apply
the heavy feed and watch the work's parting line peel right off.

Since we're stuck with the motor arrangement (barring substantial and
expensive mods) only rigidity and tool quality and sharpness can be
controlled and tuned/improved.

Craig

--- In 7x12minilathe@..., "russlbowen1958
<moldproducts@a...>" <moldproducts@a...> wrote:

Craig:
I guess my biggest problem is not having hands on experience

Absolutely, and cannot be correctly without considerable airfares -
shudder!.

1) I'm guesiong that the chinese lathes are good enough to hold +/-
.0005 on a .5 to 2" diameter x 1" Long. so why pay $3500. for the
Prazi, when for $1200 - $1500. you can have the lathe with all
accessories?

This observation is rather like a Hundai vs BMW comparison; fit,
finish, refinement, etc., which I think is accurate regarding the
subject lathes.

2) If this is the case is the lathemaster 8 x 14 the one to have or
is it just a smaller 9x20? (I'm not impresed with the jet 9x20)

Here's a webpage of an individual with some experience on a couple of
the subject lathes:

3)Is the Micro Mark as good as it looks or are there electrical
problems with the variable speed as in others?

The MicroMark is a Sieg 7x12 lathe like the others; Grizzly, Homier,
HF, Northern Tool, Enco, etc.

4) Are the older atlas or south bend lathes better or worse at
holding tolerances than the chinese?

No experience here, but I wish we lived in the world of the past with
such as these available new.

I appreciate all the help I can get. The problem is if I ask a
dealer these questions they always try to build up thier product and
downgrade the others.

No arguement from me on this.

Craig

Al,

I like your idea of turning the lathe manually. I have been wanting
to make a crank arrangement for threading manually, but had not
thought of using the same method for parting off.

Craig

--- In 7x12minilathe@..., "fromday2 <aldayis@a...>"
<aldayis@a...> wrote:

I have the HF QCTP and have had the same problem. As others have
stated slow speed is an answer. I have even turned off the lathe

and

turned the chuck by hand while feeding the cross slide, it worked
very well, much better than you might think.

HTH

Al Day


--- In 7x12minilathe@..., "wdannhardt <wdannhardt@y...>"
<wdannhardt@y...> wrote:

I recently purchased a 7 x 12 mini lathe, and so far it has been
wonderful, I am very satisfied. I purchased a quick change tool
holder from HF, and with a modification to the compound, now have
easy tool height adjustment. The only tool I have problems with

is

the cut off tool.

I am using a .062" x .5" HSS tool, cutting brass and Aluminum. I
always seem to get terrible chatter. I made sure the saddle,

cross

slide and compound are very tight to the ways, but it still

happens. WD

Sometimes, though, a nice finish cut is needed and the work has no
place to clamp in the chuck for a finish facing cut, or may be marred
by the chuck (although brass shims may be used in this case).

Frequently order of operations may solve the above, but sometimes not.

Craig

--- In 7x12minilathe@..., "roylowenthal
<roylowenthal@y...>" <roylowenthal@y...> wrote:

There's also a lot to be said for hacksaw parting, followed by a
facing cut :-)

Roy
--- In 7x12minilathe@..., Frank Hoose <fhoose@y...>

wrote:

I tend to use the cutoff tool only for stock 1/2" dia.
or less. For bigger stuff, I use the bandsaw.

Frank Hoose


--- "Craig C. Hopewell
<chopewel@r...>"
<chopewel@r...> wrote:

I've had similar problems. First make sure the "T"
type parting tool
is absolutely perpendicular to the work because that
type tool has no
side relief. Try lowering the tool a few
thousandths below center.

A tool ground from square stock (a lot of grinding)
with side reliefs
tends to work better for me, but has some limitation
on cutting depth.

Parting off is, to me, difficult and slowing the
lathe down as is
necessary for such operations reduces motor power.

Craig

--- In 7x12minilathe@..., "bbftx
<bflint@a...>"
<bflint@a...> wrote:

WD
How big a diameter are you trying to part off? A

lot of people

have difficulties with this. It gets dicey on my

7x12 on anything

more than 1-1/8" in diameter. I seem to get the

best results

slowing the rpms way down, as low as I can go with

the speed

control. Also, I make sure I have as little of

the parting tool

as possible hanging out from the tool holder.
B Flint


--- In 7x12minilathe@..., "wdannhardt

<wdannhardt@y...>"

<wdannhardt@y...> wrote:

The only tool I have problems with is
the cut off tool.

I am using a .062" x .5" HSS tool, cutting brass

and Aluminum. I

always seem to get terrible chatter. I made

sure the saddle,
cross

slide and compound are very tight to the ways,

but it still

happens.

Does anyone have any suggestions to make this

better?

I've not heard of anyone else complain about

this, so I think it

must be something I am doing.

WD

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I have experienced all the problems with parting and, as one member said,even
turned the chuck by hand. With my 7X14 the circuit breaker trips as soon as
the tool hogs. I'm attempting to make a small crankshaft for a model rotary
engine and there is a strong thrust to the piece as it rotates. I have fed as
little as .0001 per turn what really amounts to a scrape. Can anyone explain,
technically, why parting is so difficult?
Max

The product reviews at:

are accurate and honest. The Asian minis can meet your accuracy
needs; they may need some tweaking - the basic pieces are decent, fit
& finish can be improved. In my less charitable moments, I refer to
them as "lathe kits," to be finished by the buyer.
Unless you can afford a Hardinge, everything will have
shortcomings.

Roy
--- In 7x12minilathe@..., "russlbowen1958
<moldproducts@a...>" <moldproducts@a...> wrote:

I'm so confused. The more I read about mini lathes, the more
uncertain I become on which one to buy. I've read that Prazi is

the

best at close tol.work, but is +/- .0005 close for 1" dia. x 1"long
420 stainless steel? Shouldn't the asian lathes do that? What

does

Prazi give you for $1000 - $2500 extra dollars? And which report do
you believe? Is the Taiwan built CH 350 the best or does the

aluminum

bed blow it? Then I read that the LatheMaster 8 x 14 is the new
champ, and the 9 x 20s are crap. Some say that the older american
lathes like atlas or south bend are better than the new chinese
machines but I find that hard to believe. They were probably good

40

years ago but even China is not that far behind. To me the Micro -
Mark 7 x 14 looks good, but without being able to see eone or run

one

I am trying to rely one reports I read on the internet. But they
seem to be of all different opinions. Can you guys help me out? I
Own a company that designs and builds small inserts for the

plastics

industry. I am really looking for a toy that can also make small
inserts from 420 Stainless Steel @ 33 HRc. I know large machines
(Mazak, Lablond, Clausen etc. but can't seem to get a straight read
on the small market. You guys know this market. Help!

True enough. I use the 4-jaw when I need absolute
concentricity on an existing workpiece. Not to put
down Rick's idea - I think it's great and will
probably make one someday.

Frank Hoose


--- "roylowenthal <roylowenthal@...>"
<roylowenthal@...> wrote:

OTOH, when you're doing repairs/mods to existing
stuff, the lack
of concentricity is a problem. I'm using the 4 jaw
until I finish
the Rick Kruger style adjustable backplate (I'm too
cheap to go the
collet route.)

Roy
--- In 7x12minilathe@..., Frank Hoose
<fhoose@y...> wrote:

Something to keep in mind: a little runout of the
chuck, say .002 or .003 won't affect most projects

as

long as you don't remove the workpiece from the

chuck

until all operations are completed.

The reason is that as soon as you turn the

workpiece

down by more than .004, the resulting workpiece is
exactly concentric with the lathe axis within the
accuracy of the spindle bearings (typically .0002

-

.0005 on the minilathes).

This is why I was able to turn a piece of brass

down

to .034 dia. and then drill a .016 hole through

it.

lathe.com/Mini_lathe/Capabilities/Capabilities.htm#tiny

More recently, I needed some test pins for making
temporary connections to a tiny DIN connector on a
video camera. I turned the pins from brass to a

dia.

of .020. They were concentric even though the 4"

chuck

holding the 1/8 brass stock I started with

probably

has about .003 runout.

Frank Hoose


--- "Craig C. Hopewell
<chopewel@r...>"
<chopewel@r...> wrote:

John,
I have not heard of this problem before, but I

am

new
to the hobby, and if any lathes had this

problem I

would
have expected it on mine ( 8^) or 8^( - don't

know

which).

I would want this to be accurate, especially if
removing
and mounting the chuck regularly. If under
warranty I
would request a new spindle. If not under

warranty

a
new spindle is available from
www.littlemachineshop.com
for $29.95. Alternatively, an adapter plate
similar to
those necessary for a four inch chuck could be
made.

Craig

--- In 7x12minilathe@..., "John
<moran03@e...>"
<moran03@e...> wrote:

The raised land on my spindle plate measures

2.154

rather than 2.165

as given on the mini-lathe site. Sure enough,

the

recess in the
chuck

measures 2.165.

In order to mount my 3 jaw chuck I first snug

the

nuts slightly, put

a rod in the chuck, and use an indicator on

the

rod. I rotate the

chuck so the high point is up and tap the

chuck on

the top with a

block of wood; this is not a well controlled

process so it typically

takes several minutes to get TIR between 1 and

2

mils, when I
tighten

the nuts.

Is there a better way to center the chuck?

Is the mis-match between the land and the

recess

common? I expected

the chuck to center itself on the spindle land

but

this mis-match

apparently precludes that.

John

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There's also a lot to be said for hacksaw parting, followed by a
facing cut :-)

Roy

Parting problems are a recurring issue; you've happened to hit a
temporary lull :-)
Make sure the tool is truly vertical - my HF holder needed some
shimming to properly hold a "T" blade. It also has to be
perpendicular to the work, & has to stay that way - my HF QC post
tries to rotate around the mounting bolt.
The tool needs to be honed sharp and exactly on center. When
they're low, they cut beautifully, right up until the work climbs the
tool! Also, a carriage lock helps; using the half-nuts on the
leadscrew is not really solid enough. Low speed helps; you want a
continuous chip, so slow, steady feed & low spindle speed.
Rear parting lets the tool stay mounted (I swear they remount at
different heights due to fat air molecules) speeding up work and lets
the tool be forced away from the work, instead of into it when it
tries to "grab."

Roy
--- In 7x12minilathe@..., "wdannhardt <wdannhardt@y...>"
<wdannhardt@y...> wrote:

I recently purchased a 7 x 12 mini lathe, and so far it has been
wonderful, I am very satisfied. I purchased a quick change tool
holder from HF, and with a modification to the compound, now have
easy tool height adjustment. The only tool I have problems with is
the cut off tool.

I am using a .062" x .5" HSS tool, cutting brass and Aluminum. I
always seem to get terrible chatter. I made sure the saddle, cross
slide and compound are very tight to the ways, but it still

happens.

Does anyone have any suggestions to make this better? I've not

heard

of anyone else complain about this, so I think it must be something

I

am doing.

Thanks for your help,
WD

I tend to use the cutoff tool only for stock 1/2" dia.
or less. For bigger stuff, I use the bandsaw.

Frank Hoose


--- "Craig C. Hopewell
<chopewel@...>"
<chopewel@...> wrote:

I've had similar problems. First make sure the "T"
type parting tool
is absolutely perpendicular to the work because that
type tool has no
side relief. Try lowering the tool a few
thousandths below center.

A tool ground from square stock (a lot of grinding)
with side reliefs
tends to work better for me, but has some limitation
on cutting depth.

Parting off is, to me, difficult and slowing the
lathe down as is
necessary for such operations reduces motor power.

Craig

--- In 7x12minilathe@..., "bbftx
<bflint@a...>"
<bflint@a...> wrote:

WD
How big a diameter are you trying to part off? A

lot of people

have difficulties with this. It gets dicey on my

7x12 on anything

more than 1-1/8" in diameter. I seem to get the

best results

slowing the rpms way down, as low as I can go with

the speed

control. Also, I make sure I have as little of

the parting tool

as possible hanging out from the tool holder.
B Flint


--- In 7x12minilathe@..., "wdannhardt

<wdannhardt@y...>"

<wdannhardt@y...> wrote:

The only tool I have problems with is
the cut off tool.

I am using a .062" x .5" HSS tool, cutting brass

and Aluminum. I

always seem to get terrible chatter. I made

sure the saddle,
cross

slide and compound are very tight to the ways,

but it still

happens.

Does anyone have any suggestions to make this

better?

I've not heard of anyone else complain about

this, so I think it

must be something I am doing.

WD

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I think it's an arbitrary amount. If you make too much adjustment
range, there's no particular downside; if you make too little
adjustment range, it's easy to increase. At some point, the mounting
studs hit the sides of the spindle holes, setting an upper limit for
adjustment.
My plan was to make the maximum adjustment range possible, on the
theory that I've never regretted having more adjustment capacity on
anything.

Roy
--- In 7x12minilathe@..., "bbftx <bflint@a...>"
<bflint@a...> wrote:

Roy and Al:
I'm making an adjustable backplate too. One thing I question
in Rick's otherwise great design is the amount of adjustment
he built in. .050" oversize on the diameter seems like too much
to me.
I can't imagine needing to adjust more than a few thou. Wouldn't
a .005 to .010" oversize diameter give a person enough adjustment?
Regards,
B Flint


--- In 7x12minilathe@..., "roylowenthal
<roylowenthal@y...>" <roylowenthal@y...> wrote:

Al,
I agree; I'm in the process of making the same one!

Roy
--- In 7x12minilathe@..., "fromday2 <aldayis@a...>"
<aldayis@a...> wrote:

Roy, I saw Rick Kruger about a month ago and one of the

intresting

things in his shop is the adjustable backplate. The idea and
execution were clever and well done. I am going to make one
for a 4" 3jaw I have. His was nice looking, the concept is
simple enough that it should be reasonably easy to do.

Al Day

I have the HF QCTP and have had the same problem. As others have
stated slow speed is an answer. I have even turned off the lathe and
turned the chuck by hand while feeding the cross slide, it worked
very well, much better than you might think.

HTH

Al Day


--- In 7x12minilathe@..., "wdannhardt <wdannhardt@y...>"
<wdannhardt@y...> wrote:

I recently purchased a 7 x 12 mini lathe, and so far it has been
wonderful, I am very satisfied. I purchased a quick change tool
holder from HF, and with a modification to the compound, now have
easy tool height adjustment. The only tool I have problems with is
the cut off tool.

I am using a .062" x .5" HSS tool, cutting brass and Aluminum. I
always seem to get terrible chatter. I made sure the saddle, cross
slide and compound are very tight to the ways, but it still

happens. WD

I have not made the adjustable back plate so I cannot speak from
experience but I would guess you are right. It would seem that .010
would be enough adjustment for a chuck that does not have other
serious problems and would likely not be accurate at different
openings. The particular chuck I have that is a problem has .003
runout. HTH

Al Day


--- In 7x12minilathe@..., "bbftx <bflint@a...>"
<bflint@a...> wrote:

Roy and Al:
I'm making an adjustable backplate too. One thing I question
in Rick's otherwise great design is the amount of adjustment
he built in. .050" oversize on the diameter seems like too much
to me.
I can't imagine needing to adjust more than a few thou. Wouldn't
a .005 to .010" oversize diameter give a person enough adjustment?
Regards,
B Flint


--- In 7x12minilathe@..., "roylowenthal
<roylowenthal@y...>" <roylowenthal@y...> wrote:

Al,
I agree; I'm in the process of making the same one!

Roy
--- In 7x12minilathe@..., "fromday2 <aldayis@a...>"
<aldayis@a...> wrote:

Roy, I saw Rick Kruger about a month ago and one of the

intresting

things in his shop is the adjustable backplate. The idea and
execution were clever and well done. I am going to make one
for a 4" 3jaw I have. His was nice looking, the concept is
simple enough that it should be reasonably easy to do.

Al Day