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Roy & John, thanks. I'm sure I'll figure it out, but wanted a starting
point. Your explanation of the tables explains why the calculator
tells me I should be turning a 1/2" aluminum rod at 4,000 RPM.

In case you missed it, Paul Moir posted a useful cheat sheet today.
What makes it particularly handy is that, in addition to showing the
appropriate speed for a given material & Diameter, he gives you a guid
to show approximately what dial position represents any given speed.
Very useful.

Forgot to mention; the heated object color vs. temperature tables all
assume you're in a very dimly lit room. Think, back corner of a
blacksmith's shop in the pre-electric light days. If you use the
magnet method, you'll be at the Curie temperature, which is where you
want to be. If you have the magnet on a string you can swing it at
the piece you're heating & quickly tell when it's hot enough.

Roy

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

You should be able to get it hot enough with a MAPP torch. Don't
forget, you're only trying to heat treat the working end, not the
whole tool. I'm basing that on what my Turbo torch will do; I

assume

your MAPP torch uses a similar approach to get enough combustion

air

for a hot flame.

Roy

--- In 7x12minilathe@..., <gregorstransky@> wrote:

Another question from a beginner. According to a basic book about

home

machinery it is possible to temper metal using a MAPP gas torch.

I

have

tried this on a 4x1/2 punch made out of annealed 4140 with a

standard MAPP

gas torch suitable for plumbing work. I was unsuccessful because

the punch

did not get hot enough. Any suggestions? Thank you.
Gregor Stransky, San Antonio, Texas

Hi Gregor,

A rough rule of thumb for that 'magic temperature' is a good cheery
red glow. A similarly rough guide to tempering the hardness is to
use the oxide colour. After quenching to harden, clean a bit back to
bright steel. Watch the changing oxide colours as you re-heat. A
light straw is usually about it. Maybe a little darker towards
purple if you need a little softer. Experiment. Also see
www.navaching.com/forge/heat.html (scroll down to the bottom).

John


--- In 7x12minilathe@..., "ralph_pattersonus"
<rpatter1@...> wrote:

Hardening steels requires reaching a 'magic temperature', which I

do

not actually remember, or have the capability to measure.

However, I

am told that it coincides with the temperature at which the metal

is no

longer magnetic. If you have a magnet with a handle available,

simply

heat the material and frequently test it with your magnet. When

the

magnet is no longer attracted to the heated portion, it is time to
quench. The resulting condition of the material should be glass-

hard,

anwhich is very brittle, and the part must be tempered in a hot

oven

for a while to partially soften the metal to a usable state. How

hot

and how long must be looked up in a reference document.
HTH, Ralph

--- In 7x12minilathe@..., <gregorstransky@> wrote:

Another question from a beginner. According to a basic book

about

home

machinery it is possible to temper metal using a MAPP gas torch.

I

have

tried this on a 4x1/2 punch made out of annealed 4140 with a

standard

MAPP

gas torch suitable for plumbing work. I was unsuccessful because

the

punch

did not get hot enough. Any suggestions? Thank you.
Gregor Stransky, San Antonio, Texas

I have a Warco WM180V 7x12 as does at least one other UK member of this forum. I have had my one for just over a Year and believe it to be a lovely little lathe. Trawling through the Internet I have found the address of the original manufacturer of these lathes in China. They can be found at I don't know if any US seller re-badges these, but it might be worth an email to the company. I know this site is virtually dedicated to the Seig mini lathe, but for just a little bit more cash you can have one of these. Warco provide all the optional items free, except the Collet Chuck and Collet Holder.

Robin

Hi Roy, Ed,

While I pretty much agree with you Roy, I found it useful to
reference some tables initially. Starting from a pretty low
experience base it was reassuring to know I was in the ballpark for
my material.

John


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

It's not worth the effort to calculate speeds! In production

shops,

it's a big deal, on the concept of "time is money." For hobbying

it's

easier to just start slow & increase speed until either the

machine

protests or you get uncomfortable with it. The nifty speed/feed

tables

you see are intended for maximum throughput on infinitely rigid,

flood

cooled production machines with no consideration for tool life.

As a

generality you'll get better tool life at lower speeds & lighter

feeds,

to a point where you can spend your time making things instead of
sharpening tools.

Roy

--- In 7x12minilathe@..., "Ed" <edo@> wrote:

I order a Homier over the weekend and got it today! I had

planned on

spending the evening cleaning it up, but there was no red grease

to be

found. All the bare metal had a light coat of oil on it. The back
splash and pan were both dented, but no creases and I was able to
straighten them out just fine.

Unfortunately, my Enco order won't arrive until tomorrow so I

have no

tools yet (or anything to cut).

I ran it per the instructions to break it in and realized that

2500

RPM is pretty fast. I was surprised at how quietly and smoothly

it

runs. What speeds are used for cutting aluminum? steel?
Ed

Hardening steels requires reaching a 'magic temperature', which I do
not actually remember, or have the capability to measure. However, I
am told that it coincides with the temperature at which the metal is no
longer magnetic. If you have a magnet with a handle available, simply
heat the material and frequently test it with your magnet. When the
magnet is no longer attracted to the heated portion, it is time to
quench. The resulting condition of the material should be glass-hard,
anwhich is very brittle, and the part must be tempered in a hot oven
for a while to partially soften the metal to a usable state. How hot
and how long must be looked up in a reference document.
HTH, Ralph

--- In 7x12minilathe@..., <gregorstransky@...> wrote:

Another question from a beginner. According to a basic book about

home

machinery it is possible to temper metal using a MAPP gas torch. I

have

tried this on a 4x1/2 punch made out of annealed 4140 with a standard

MAPP

gas torch suitable for plumbing work. I was unsuccessful because the

punch

did not get hot enough. Any suggestions? Thank you.
Gregor Stransky, San Antonio, Texas

It's not worth the effort to calculate speeds! In production shops,
it's a big deal, on the concept of "time is money." For hobbying it's
easier to just start slow & increase speed until either the machine
protests or you get uncomfortable with it. The nifty speed/feed tables
you see are intended for maximum throughput on infinitely rigid, flood
cooled production machines with no consideration for tool life. As a
generality you'll get better tool life at lower speeds & lighter feeds,
to a point where you can spend your time making things instead of
sharpening tools.

Roy

You should be able to get it hot enough with a MAPP torch. Don't
forget, you're only trying to heat treat the working end, not the
whole tool. I'm basing that on what my Turbo torch will do; I assume
your MAPP torch uses a similar approach to get enough combustion air
for a hot flame.

Roy

--- In 7x12minilathe@..., <gregorstransky@...> wrote:

Another question from a beginner. According to a basic book about

home

machinery it is possible to temper metal using a MAPP gas torch. I

have

tried this on a 4x1/2 punch made out of annealed 4140 with a

standard MAPP

gas torch suitable for plumbing work. I was unsuccessful because

the punch

did not get hot enough. Any suggestions? Thank you.
Gregor Stransky, San Antonio, Texas

Those little ones are primarily intended for "chip carving" not lathe
use. The bigger ones look like a generic carving set, not a lathe
set. Still, for small work, anything you can make work is a suitable
tool. The size of the machine makes pen turning tools about the
right general size, here's what they look like:



No particular connection except as a satisfied customer of theirs for
the last 30 yrs:-)

Roy

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

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

Vikki, congrats - I didn't say anything earlier, but i thought

to

myself that with those tools it would be a miracle if you can do
anything. Just wait till you get your hands on a true HSS

gouge.

Thanks Barry!

Those chisels seem to cut well enough, but most of them are just

huge

for the space and what I am trying to do, so it seems to me.

Biggest problem seems to be not much room, especially at the ends

with

the tool post and all that in the way.

Will try something with the small set and see what happens. I

suspect

that what I need will be between the two :-/.

Thanks & take care, Vikki.

Hi Steve,

I too have been pondering what size mill would suit my needs. Not
ready to buy yet but gathering info on what to write on my wish
list. Your advice seems fine but relative. What sort (and size) of
jobs are you doing? If a guy only needs to mill work up to 100mm
does that change your advice?

John


--- In 7x12minilathe@..., "cedge11" <cedge@...> wrote:

Gregor
The Mini Mill sometimes proves to be a bit cramped for space and
travel. The Micro Mill, which is even smaller, would be very

limiting

in what you would be able to do with it. I'd probably nudge you

toward

the larger Mini Mill just to keep the predictable curses from

scaring

small children. A bit more expense, but it's also a quite bit more
machine.

Steve

--- In 7x12minilathe@..., <gregorstransky@> wrote:

Hi:
I just joined the group. I only recently became interested in

home shop

machinery and have been doing some lathe work on my 7x12

Cummins. I

plan to

buy a mill in the near future. Does anybody have any experience

with

the

HarborFreight Micro Mill/Drill that sells for $299? I already

posted

the

same question to the mini-mill group, but received only a few

responses.

Thank you.
Gregor Stransky, San Antonio, Texas

Very nice. Thanks!

Gregor, while I am no expert, generally there are three terms that
are used in heat treating - annealing, hardening , and tempering.
each metal has its own specifics but for example for o-1 ( aka oil
hardening ) its is annealed by heating it to a critical temperature (
for 0-1 when it is no longer magnetic ) then allowing to cool
slowly, often while packed in ashes. Once annealed it is at its
softest state and that is when it is shaped to rough form. The next
step is to again heat it to the critical temp then plunge it in the
appropriate coolant ( for o-1 warm oil) once it is quenched it is as
hard as it will get, but it is very brittle - to make it less brittle
it is tempered by heating it to a specific temp ( depending on how
hard you want it - the 350 -400 range is common for hand tools for
working wood). If you overheat it at this stage and make it too
soft, you can start again ( though I usually skip annealing and just
heat treat it, then after quenching, temper it again)

From another site I found this- The proceedure for 4140 is preheat to
1250 deg F then bring it up to 1550 deg F. Let it soak at temp for
probably 15-20 min and oil quench. Max hardness on 4140 is around 55
Rc I don't think you would want it that hard my sugestion would be to
draw it back to about 46-48 Rc.

Unless your part is very big you should have no problem getting it up
to 1550 with a MAPP torch, though I don't know how you would confirm
you reached that temp. Here is a site with a short description of
the temps for that metal

Family=Alloy+Steels&MetalName=4140

Very useful.
Thanks.
-JC

I made up a cheat sheet for setting the RPM on my minilathe for
various materials and diameters, and thought some folks here could use
it too.

Here it is in PDF:


And ODG:


The ODG file is editable with OpenOffice Draw, which is freely
available for just about any platform. You'll need this file to
change the knob RPM maps and SFM to suit your lathe & turning habits.
The PDF file is really just so you can see it without OpenOffice.

The table is a spreadsheet. To adjust it's values, right click on it
and select "EDIT". Then just change the SFM value and the other
fields will recompute. It rounds to 50 rpm unless sufficiently slow,
where it rounds to 25rpm. When you're done, just hit <ESC> and print it.

Since I have mostly HSS tooling, that's what the table is set for. I
figure it's easy enough to double the numbers mentally for carbide.
The RPMs were checked with a laser tachometer.

I hope someone else finds this useful!

-Paul Moir

Another question from a beginner. According to a basic book about home machinery it is possible to temper metal using a MAPP gas torch. I have tried this on a 4x1/2 punch made out of annealed 4140 with a standard MAPP gas torch suitable for plumbing work. I was unsuccessful because the punch did not get hot enough. Any suggestions? Thank you.
Gregor Stransky, San Antonio, Texas

--Hi Rance,

Not sure where your looking, but in the 2007 Grizzly catalog
(pg.614) they are $2.95 ea. I bought three, 1/32,1/16,1/8 with a 7/8
hole a few years ago when I first got my mini mill, during an
accessory "buying spree", just to have around. Shortly after that I
bought several end mills, taps, R-8 colletts, and more from someone
at a flea market selling tons of machine accessories that were used,
but well cared for, and no Asian stuff, all high quality prfessional
shop stuff, and I got a few 1/2" hole slitting saws with the bunch
of stuff, all for about $15! The biggest disappointment of all of it
was the "fits all" arbor from Grizzly. I don't use the saws alot,
but they're nice to have on hand. Certainly not a "must have" for
just starting out though. I cut alum. dry, steel needs cutting
fluid, w/ slow feed. Use some type of shield, they spray alot of
fluid!

Frank

- In 7x12minilathe@..., "rancerupp" <rupps@...> wrote:

Thanks Frank,

So is $9-$10 about the going price for :

Diameter (Inch): 2-1/2
Face Width (Inch): 1/16
Arbor Hole Size: 7/8
Material: HSS
Number of Teeth: 28
Type of Tooth: Plain Tooth

or should I look elsewhere since it prob. won't be the first
accessory I'll be wanting to use? Thanks.

Rance

PS: I think I'll just make my own arbor. Only need one size for

now.

--- In 7x12minilathe@..., "nyceacres200"
<nyceacres200@> wrote:

--- Hi Rance/Vikki,
For the occaisional times I need a slitting saw, I bought a few
from Grizzly a couple of years ago 2.5" dia. w/ a 7/8" hole, in
different thickness', and the "fits all" arbor. I found that the
saws don't run true with that arbor, although with care, they

work.

I also bought some smaller dia. (I think they're 1.75" dia) with

a

1/2" hole, at a flea market, for literaly pennies. The 1-1/4"

dia.

of the arbor leaves very little blade showing on the smaller

ones.

I

made a 7/8" arbor from alum. round stock, and a 1/2" arbor from

3/4"

round steel rod. They work much better,the saws run true, and

are

easier to use. And easy to make. The 3/4" rod arbor for the

smaller

saws leaves more cutting room. The diameter and thickness of the
saws depend on your needs. So far these few sizes have worked

for

me. If blanks are available, making your own is even easier.

Frank

G'donya John!

Ian
--- In 7x12minilathe@..., "born4something" <ajs@...>
wrote:

Hi Ian,

See my responses interspersed.


--- In 7x12minilathe@..., "steam4ian" <fosterscons@>
wrote:

G'day John.
Firstly, I am not retired and out of it, I have my own engineering
consulting business of which I am both director and an enployee,

it

supports my other activities.

We do have a lot in common. That's my situation too. I haven't had

much

call for OH&S awareness thrust at me in this role. Pre 2003 I was

middle

managing in the public sector so awareness and compliance was really
pushed. If you go through the current competency based national
qualification scheme for any trade you'll get to do the OH&S ticket

and

learn all about it. I did a data cabling cert a while back and had

to do

it. My prior quals assumed it but when I wanted to add another

ticket I

got caught up in it. Similarly, a friend with a solar heating /

plumbing

company and a dozen employees gets tangled in it. Largely once you

get

involved with the construction industry at a hands on / employer

level.

My own company has only one employee (manager, secretary, director,

tea

maker - me) mostly doing design work so I haven't needed to worry

much.

Do you have other employees?

My thoughts still stand with respect to the home machinist. If the
machine is used by your employees then application of a guard or

some

similar "engineering" measure is esential. But, the ACTUAL hazard
must be identifed. It is pointless guarding the chuck and leaving

a

rotating workpiece exposed. The hazad of the key being flung out

is

real but the guard is not necessarilly the solution. As an
alternative the key could be set in a holder that de-energises the
lathe when the key is not in the holder.

Agreed. But shhh... Don't mention the rotating work as well!
Interestingly, my machine was delivered with a light spring slipped

over

the chuck key. It was just strong enough to eject the key from the

chuck

if you weren't constantly holding it in. You could not let go when

you

regripped the key while adjusting the chuck without having to fetch

the

key back out of the chip tray!

The chuck guard is grandma engineering, reaction not application.
Eventually we could have to fully enclose the lathe like a CNC
machine.

Only reason we don't is historical precedence. The modern automobile
could not be launched today unless fully computerised driving and

crash

avoidance were developed first. What's this human in control?! And

then

there's the hammer, chainsaw, ...

Did Sieg stuff up or those who ordered the machines from them?

Since others in various countries have reported the same 6" figure

on

the 7x12 machines I doubt it was just my distributor. It's looking
pretty universal.

If the chuck guard is to be retained you either put up with the
reduced swing or change the mounting of the guard as you

suggested.

Few users of the lathe will be swinging the full 7 inches but
interference with the standard faceplate is a different matter.

Not having a full 7" didn't really worry me either. But I was mighty
cheesed when I bought their faceplate and had to remove the supplied
guard to fit it. After trueing the faceplate up I haven't used it

again.

I've made do with the 4-jaw a few times where the faceplate would

have

been the more logical choice. <G>

I don't know what it is about these lathes but they bring out a

rash

of complaints in some people. For me, I am just happy to have a
lathe; even more so one that is not such a sacred cow that I am
unwilling to tamper with it. It is amazing, if you stuff a part

up it

is just an email to someone like LMS and you are underway again at
comparatively little cost, few other lathes offer that

opportunity.

Got that off my chest!

I hearty hear, hear! I'm in no doubt on that one. My budget was $1k

and

that's sorta where I ended up with some accessories. Ok, I cribbed

a few

more accessories than that. But no, I'm not complaining overall. I

can

live with having to lap my gibs, align the tailstock, clean up the

odd

burred thread, fitting an apron swarf guard, etc. But some things

are

harder to rectify properly. That guard is one of them. Yeah, I had

to

get that off my chest too!

And yes, I love the spares situation too. I have and old ex Water

Board

aluminium runabout. Before I owned it I doubt it ever saw a boat

ramp.

Just a rocky hillside into a dam. It was a workboat and had a hard

life.

Very little paint left after 30 years. Gee I love that Ugly

Duckling. I

never worry about fenders to keep it from being scratched on

barnacles.

Or people scratching the paint with shoes. It's really laid back and
comfortable. I'm feeling that way about my 7x12 after 4 months due
largely to LMS being on standby!

One good turn deserves another.
Regards to all,
Ian

Keep on turnin',
John

FYI, check out the GrizHFMiniMill mailing list. I find it much more
useful then the minimill list.

Some, Gregor - other than price, it's not much. It's a good mill if you're
planning on doing only very small parts. Even the "Mini" mill is definitely
NOT a Bridgeport.

You have to remember the intent of the designers on these machines and keep
their limitations in mind.

Rabid
Uncle Rabid ( )
We Repair Electronic Speed Controllers
For Asian Mini Lathes and Mini Mills
"Just Crazy Enough To Get the Job Done"
(Join Rabid's Lathe/Mill Controller/Mod's List!)
(Also visit BarStockEngines - join us in building without Castings!)