开云体育

Barryvabeach wrote.....Unless your part is very big you should have no problem getting it up to 1550 with a MAPP torch........

Don't forget to surround the part with some heat resisting bricks to make a simple hearth. It concentrates the heat where you want it. I used parts from an old gas fire.
HTH
Ellis

G'day again John, Gregor.
Your description "If that sounds too rushed a similar technique is to
quench harden the whole end. Clean up in slow time, then wave the flame
gently at the shaft an inch or two back from the tip and watch the
oxides at the tip as the heat flows down the shaft as above. Again,
quench to taste." is the method I described. True, I didn't harden the
whole tool. Applying the second heat so the tip is not over heated is
the key. It works for me.
I down loaded some heat treatment and related stuff from various
sources; as far as I know it is public domian. If you want a copy drop
me an email.

OGTDA

Regards,
Ian

On Thursday 22 March 2007 04:31, gregorstransky@... wrote:

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've got a Micro Mill converted to CNC and ran it manual for over a year before that
out of the box its a pretty nice machine to work with but its small ,so very small
adding the long table and extended base from LMS kicks it up to a much more
usefull size (more travel and bigger table than the minimill) but it kicks the price up as well
(and you end up with 2/3 of a new machine sitting under the bench)

Brian
--
"Nemo me impune lacesset"

Hi Gregor, Ian,

I had a really good colour chart in a metalworking text back in
school days but that link's the nearest I've found to it.

What you're trying to do is snap freeze the steel in a particular
state, rendering it ridiculously glass-hard, then re-heat it just
enough to partially reverse the process so it's still hard enough to
be useful without being as brittle as glass. That's my condensed
layman's view of the process.

A useful technique I first learnt from my school metalwork teacher
was to heat the end couple of inches of a screwdriver to cherry red,
quench the end inch or so, give the tip area a quick clean with
emery and then watch the oxide colours as the heat flows into the
tip from the rest of the shaft. Quench to taste.

If that sounds too rushed a similar technique is to quench harden
the whole end. Clean up in slow time, then wave the flame gently at
the shaft an inch or two back from the tip and watch the oxides at
the tip as the heat flows down the shaft as above. Again, quench to
taste.

BTW, "taste" varies with application. A tile scoring scriber can be
pretty hard. If a cold chisel were that hard it may chip in use.
These methods ensure the tip is as hard as you need while the
adjacent shaft is not left glass hard. If you try to do the
tempering process from the tip end you'll likely leave a brittle
glass-hard zone just above the tip.

Grab an old screwdriver and have a play. It all sounds far more
complex than it is until you do it. It can be. Professionally,
programable temperature controlled ovens are used for repeatable
results on large jobs like car leaf springs. But a propane or butane
torch can do pretty well in the backyard shop using nothing more
than the colours and a bucket of water. Just as long as you start
with a tool steel. Mild steel doesn't have the right range of carbon
content (unless you case harden it but that's another subject).

John



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

G'day Gregor & John.

I seem to have good results heating to dull cherry red and

quenching.

Then cleaning the surface back to bright. Tempering is done by
heating the body of the tool until the it is straw generally and
mauve going towards purple at the tip and then quenching the tip
only. do'nt over heat the tip or it wil be brittle
It has worked marvels on a cheap cold chisel and some spring steel
rod I bought from a model shop.

The colour charts in John's link are most helpful. The whole

process

sounds much more complicated than it realy is, try it. The spring
steel from the model shop is a cheap material for experimentation;

it

is used for aircraft undercarts.

You haven't given the size of the torch. I have used the wok

burner

on the kitchen stove!

One good turn deserves another.
Regards,
Ian

John
Taking into consideration that once you have the mill, you'll
constantly find more things it can do or that you'll want it to do.
I'd probably have to stand by my suggestion. By the time you have a
small machinst vise strapped down to the table with your work material
in place and a collet loaded with an end mill, you'll discover the
available Z axis disappears far too quickly.

I don't want to spend your money for you. I'll just say that even
though I only make parts for small steam engines, I'm already fighting
the temptation to move up to the new X3 Seig to gain a bit more
flexibilty.

Steve
When your favorite tool is a hammer, everything around you looks like
it needs a nail.

G'day Gregor & John.

I seem to have good results heating to dull cherry red and quenching.
Then cleaning the surface back to bright. Tempering is done by
heating the body of the tool until the it is straw generally and
mauve going towards purple at the tip and then quenching the tip
only. do'nt over heat the tip or it wil be brittle
It has worked marvels on a cheap cold chisel and some spring steel
rod I bought from a model shop.

The colour charts in John's link are most helpful. The whole process
sounds much more complicated than it realy is, try it. The spring
steel from the model shop is a cheap material for experimentation; it
is used for aircraft undercarts.

You haven't given the size of the torch. I have used the wok burner
on the kitchen stove!

One good turn deserves another.
Regards,
Ian

Works fine for me. It could be something's up with the hosting site,
so I've temporarily mirrored it it on my site,

I can't seem to open that cheat sheet link....says it
is "stopped" as soon as I open it.

Anyone else have that problem?

Thanks,
Rick in CO


--- Mike Payson <mike@...> wrote:

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.



On 3/21/07, 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




Be sure to check out

for small mills and
lathes.

Yahoo! Groups Links

____________________________________________________________________________________
8:00? 8:25? 8:40? Find a flick in no time
with the Yahoo! Search movie showtime shortcut.

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!