Dear Group,

I am posting this message in an attempt to gauge interest for a project I
have been working on.
I have been a hobbyist of metalworking for some time and currently posses a
lathe and CNC milling machine which I enjoy the use of very much.
I have also cast metal using traditional foundry methods (gas / charcoal)
and this is what seeded my interest for this project.

I have designed an induction furnace which is currently in it's testing
stage.
Initially this furnace was not going to see light of day out side of my own
workshop but while demonstrating it to a friend he showed a great deal of
interest and mentioned that many like minded hobbyists may be interested in
such a device.

So I guess I am posting this to gauge interest from the group and seek
advice to what value both from usage and monetary you would put on it.

I would like to apologise in advance if members of this group see this post
as a form of spam. Please be assured that this is not my intention.
I agree it would be nice to make a little cash out of ones hobby and give up
the office job ;-)

Regards,
Steve.

On Wed, 2 Jun 2004 13:48:38 +0100, "sme"
wrote:

Dear Group,

I am posting this message in an attempt to gauge interest for a project I
have been working on.
I have been a hobbyist of metalworking for some time and currently posses a
lathe and CNC milling machine which I enjoy the use of very much.
I have also cast metal using traditional foundry methods (gas / charcoal)
and this is what seeded my interest for this project.

I have designed an induction furnace which is currently in it's testing
stage.
Initially this furnace was not going to see light of day out side of my own
workshop but while demonstrating it to a friend he showed a great deal of
interest and mentioned that many like minded hobbyists may be interested in
such a device.

So I guess I am posting this to gauge interest from the group and seek
advice to what value both from usage and monetary you would put on it.

I would like to apologise in advance if members of this group see this post
as a form of spam. Please be assured that this is not my intention.
I agree it would be nice to make a little cash out of ones hobby and give up
the office job ;-)

Regards,
Steve.

Greetings Steve,
By all means you should post any info you can. There has been much
interest in induction furnaces expressed in this group.
Cheers,
Eric

Eric, thanks for the encouragement.

Currently the system can heat 20mm tool steel to yellow / white in about six
seconds.
I am currently working on the cooling aspect using a closed loop water
supply that flows around the work coil.
The system is running at approx. a third of full power so melting of steel
should be achievable.
Additional testing and fine tuning of variable frequency is also in the
process.
All circuitry is solid state and is currently cooled by standard PC fans
which will eventually make the unit very compact and transportable.

The circuit boards where designed using Eagle PCB then cut on a CNC Denford
Starmill (1988) that I was lucky to find going for a song. Incidentally I
managed to convert this mill to run on Linux EMC patched into its original
L297 / L298 stepper drivers. The original control circuit could only hold
approx 32kb of info so this is now bypassed.

This has been a part time project with many trips to the library and
countless hours rambling the web for as much info on induction as possible.
Hopefully soon it will all payoff.... ;-)

Regards
Steve.

"Eric R Snow" wrote in message
...
On Wed, 2 Jun 2004 13:48:38 +0100, "sme"
wrote:

Dear Group,

I am posting this message in an attempt to gauge interest for a project I
have been working on.
I have been a hobbyist of metalworking for some time and currently posses
a
lathe and CNC milling machine which I enjoy the use of very much.
I have also cast metal using traditional foundry methods (gas / charcoal)
and this is what seeded my interest for this project.

I have designed an induction furnace which is currently in it's testing
stage.
Initially this furnace was not going to see light of day out side of my
own
workshop but while demonstrating it to a friend he showed a great deal of
interest and mentioned that many like minded hobbyists may be interested
in
such a device.

So I guess I am posting this to gauge interest from the group and seek
advice to what value both from usage and monetary you would put on it.

I would like to apologise in advance if members of this group see this
post
as a form of spam. Please be assured that this is not my intention.
I agree it would be nice to make a little cash out of ones hobby and give
up
the office job ;-)

Regards,
Steve.

Greetings Steve,
By all means you should post any info you can. There has been much
interest in induction furnaces expressed in this group.
Cheers,
Eric

I'd be interested - what capacity?

"sme" wrote in message
...
Eric, thanks for the encouragement.

Currently the system can heat 20mm tool steel to yellow / white in about
six
seconds.
I am currently working on the cooling aspect using a closed loop water
supply that flows around the work coil.
The system is running at approx. a third of full power so melting of steel
should be achievable.
Additional testing and fine tuning of variable frequency is also in the
process.
All circuitry is solid state and is currently cooled by standard PC fans
which will eventually make the unit very compact and transportable.

The circuit boards where designed using Eagle PCB then cut on a CNC
Denford
Starmill (1988) that I was lucky to find going for a song. Incidentally I
managed to convert this mill to run on Linux EMC patched into its original
L297 / L298 stepper drivers. The original control circuit could only hold
approx 32kb of info so this is now bypassed.

This has been a part time project with many trips to the library and
countless hours rambling the web for as much info on induction as
possible.
Hopefully soon it will all payoff.... ;-)

Regards
Steve.

"Eric R Snow" wrote in message
...
On Wed, 2 Jun 2004 13:48:38 +0100, "sme"
wrote:

Dear Group,

I am posting this message in an attempt to gauge interest for a project
I
have been working on.
I have been a hobbyist of metalworking for some time and currently
posses
a
lathe and CNC milling machine which I enjoy the use of very much.
I have also cast metal using traditional foundry methods (gas /
charcoal)
and this is what seeded my interest for this project.

I have designed an induction furnace which is currently in it's testing
stage.
Initially this furnace was not going to see light of day out side of my
own
workshop but while demonstrating it to a friend he showed a great deal
of
interest and mentioned that many like minded hobbyists may be
interested
in
such a device.

So I guess I am posting this to gauge interest from the group and seek
advice to what value both from usage and monetary you would put on it.

I would like to apologise in advance if members of this group see this
post
as a form of spam. Please be assured that this is not my intention.
I agree it would be nice to make a little cash out of ones hobby and
give
up
the office job ;-)

Regards,
Steve.

Greetings Steve,
By all means you should post any info you can. There has been much
interest in induction furnaces expressed in this group.
Cheers,
Eric

On Wed, 2 Jun 2004 15:39:14 +0100, "sme"
wrote:
That's great Steve. It sounds like this would be a great setup for
case hardening and tempering home made tools. I have a tig welder and
could use the argon to shield the part during heating and so avoid
tool wraps, flux, etc..
Eric
Eric, thanks for the encouragement.

Currently the system can heat 20mm tool steel to yellow / white in about six
seconds.
I am currently working on the cooling aspect using a closed loop water
supply that flows around the work coil.
The system is running at approx. a third of full power so melting of steel
should be achievable.
Additional testing and fine tuning of variable frequency is also in the
process.
All circuitry is solid state and is currently cooled by standard PC fans
which will eventually make the unit very compact and transportable.

The circuit boards where designed using Eagle PCB then cut on a CNC Denford
Starmill (1988) that I was lucky to find going for a song. Incidentally I
managed to convert this mill to run on Linux EMC patched into its original
L297 / L298 stepper drivers. The original control circuit could only hold
approx 32kb of info so this is now bypassed.

This has been a part time project with many trips to the library and
countless hours rambling the web for as much info on induction as possible.
Hopefully soon it will all payoff.... ;-)

Regards
Steve.

"Eric R Snow" wrote in message
.. .
On Wed, 2 Jun 2004 13:48:38 +0100, "sme"
wrote:

Dear Group,

I am posting this message in an attempt to gauge interest for a project I
have been working on.
I have been a hobbyist of metalworking for some time and currently posses
a
lathe and CNC milling machine which I enjoy the use of very much.
I have also cast metal using traditional foundry methods (gas / charcoal)
and this is what seeded my interest for this project.

I have designed an induction furnace which is currently in it's testing
stage.
Initially this furnace was not going to see light of day out side of my
own
workshop but while demonstrating it to a friend he showed a great deal of
interest and mentioned that many like minded hobbyists may be interested
in
such a device.

So I guess I am posting this to gauge interest from the group and seek
advice to what value both from usage and monetary you would put on it.

I would like to apologise in advance if members of this group see this
post
as a form of spam. Please be assured that this is not my intention.
I agree it would be nice to make a little cash out of ones hobby and give
up
the office job ;-)

Regards,
Steve.

Greetings Steve,
By all means you should post any info you can. There has been much
interest in induction furnaces expressed in this group.
Cheers,
Eric

BoDiddly thanks for your interest,

I think it would not be unreasonable to say that stock of around 30-40mm dia
could be worked.
This could be placed in a small removable crucible of which the work coil
surrounds Eddie currents will then be induced into the workpiece which acts
as a primary single coil (high amps) this causes friction that heats the
piece and eventually melts it.

This setup would be ideal for working on smallish pieces using centrifugal
lost wax casting.
In fact one of the reasons I got interested in induction stemmed from my
interest in micro gas turbines and the wish to cast inconnel turbine blades.
But I am still a little way from this, but moving in the right direction I
hope ;-)

Regards
Steve


"BoDiddly" wrote in message
...
I'd be interested - what capacity?

"sme" wrote in message
...
Eric, thanks for the encouragement.

Currently the system can heat 20mm tool steel to yellow / white in about
six
seconds.
I am currently working on the cooling aspect using a closed loop water
supply that flows around the work coil.
The system is running at approx. a third of full power so melting of
steel
should be achievable.
Additional testing and fine tuning of variable frequency is also in the
process.
All circuitry is solid state and is currently cooled by standard PC fans
which will eventually make the unit very compact and transportable.

The circuit boards where designed using Eagle PCB then cut on a CNC
Denford
Starmill (1988) that I was lucky to find going for a song. Incidentally
I
managed to convert this mill to run on Linux EMC patched into its
original
L297 / L298 stepper drivers. The original control circuit could only
hold
approx 32kb of info so this is now bypassed.

This has been a part time project with many trips to the library and
countless hours rambling the web for as much info on induction as
possible.
Hopefully soon it will all payoff.... ;-)

Regards
Steve.

"Eric R Snow" wrote in message
...
On Wed, 2 Jun 2004 13:48:38 +0100, "sme"
wrote:

Dear Group,

I am posting this message in an attempt to gauge interest for a
project
I
have been working on.
I have been a hobbyist of metalworking for some time and currently
posses
a
lathe and CNC milling machine which I enjoy the use of very much.
I have also cast metal using traditional foundry methods (gas /
charcoal)
and this is what seeded my interest for this project.

I have designed an induction furnace which is currently in it's
testing
stage.
Initially this furnace was not going to see light of day out side of
my
own
workshop but while demonstrating it to a friend he showed a great
deal
of
interest and mentioned that many like minded hobbyists may be
interested
in
such a device.

So I guess I am posting this to gauge interest from the group and
seek
advice to what value both from usage and monetary you would put on
it.

I would like to apologise in advance if members of this group see
this
post
as a form of spam. Please be assured that this is not my intention.
I agree it would be nice to make a little cash out of ones hobby and
give
up
the office job ;-)

Regards,
Steve.

Greetings Steve,
By all means you should post any info you can. There has been much
interest in induction furnaces expressed in this group.
Cheers,
Eric

Have you tried using copper tubing for your coil? I believe this is the
standard type of set up for commercial units, though they probably are
not using plumbing tube, but for a low power unit it may be usable.

sme wrote:

Eric, thanks for the encouragement.

Currently the system can heat 20mm tool steel to yellow / white in about six
seconds.
I am currently working on the cooling aspect using a closed loop water
supply that flows around the work coil.
The system is running at approx. a third of full power so melting of steel
should be achievable.
Additional testing and fine tuning of variable frequency is also in the
process.
All circuitry is solid state and is currently cooled by standard PC fans
which will eventually make the unit very compact and transportable.

The circuit boards where designed using Eagle PCB then cut on a CNC Denford
Starmill (1988) that I was lucky to find going for a song. Incidentally I
managed to convert this mill to run on Linux EMC patched into its original
L297 / L298 stepper drivers. The original control circuit could only hold
approx 32kb of info so this is now bypassed.

This has been a part time project with many trips to the library and
countless hours rambling the web for as much info on induction as possible.
Hopefully soon it will all payoff.... ;-)

Regards
Steve.

"Eric R Snow" wrote in message
...

On Wed, 2 Jun 2004 13:48:38 +0100, "sme"
wrote:


Dear Group,

I am posting this message in an attempt to gauge interest for a project I
have been working on.
I have been a hobbyist of metalworking for some time and currently posses

a

lathe and CNC milling machine which I enjoy the use of very much.
I have also cast metal using traditional foundry methods (gas / charcoal)
and this is what seeded my interest for this project.

I have designed an induction furnace which is currently in it's testing
stage.
Initially this furnace was not going to see light of day out side of my

own

workshop but while demonstrating it to a friend he showed a great deal of
interest and mentioned that many like minded hobbyists may be interested

in

such a device.

So I guess I am posting this to gauge interest from the group and seek
advice to what value both from usage and monetary you would put on it.

I would like to apologise in advance if members of this group see this

post

as a form of spam. Please be assured that this is not my intention.
I agree it would be nice to make a little cash out of ones hobby and give

up

the office job ;-)

Regards,
Steve.


Greetings Steve,
By all means you should post any info you can. There has been much
interest in induction furnaces expressed in this group.
Cheers,
Eric




--
James P Crombie
Slemon Park, PEI
Canada
Machinist - 3D Cad Design - Amateur Astronomer

http://www.jamescrombie.com

Eric it would be a nice clean table top solution no stoking of coals or use
of gas would not even have to venture outside the workshop.... great for
those winter months :-)

One thing that does concern me is safety.
If I was to sell this (cottage industry style) I could not guarantee the
safe usage or negligence from the user and in the days of ambulance chasing
litigation lawyers I could end up loosing the shirt on my back or worse so I
guess this would need a great deal of thought. Not sure how this lies as
yet!

Regards
Steve.


"Eric R Snow" wrote in message
...
On Wed, 2 Jun 2004 15:39:14 +0100, "sme"
wrote:
That's great Steve. It sounds like this would be a great setup for
case hardening and tempering home made tools. I have a tig welder and
could use the argon to shield the part during heating and so avoid
tool wraps, flux, etc..
Eric
Eric, thanks for the encouragement.

Currently the system can heat 20mm tool steel to yellow / white in about
six
seconds.
I am currently working on the cooling aspect using a closed loop water
supply that flows around the work coil.
The system is running at approx. a third of full power so melting of
steel
should be achievable.
Additional testing and fine tuning of variable frequency is also in the
process.
All circuitry is solid state and is currently cooled by standard PC fans
which will eventually make the unit very compact and transportable.

The circuit boards where designed using Eagle PCB then cut on a CNC
Denford
Starmill (1988) that I was lucky to find going for a song. Incidentally I
managed to convert this mill to run on Linux EMC patched into its
original
L297 / L298 stepper drivers. The original control circuit could only hold
approx 32kb of info so this is now bypassed.

This has been a part time project with many trips to the library and
countless hours rambling the web for as much info on induction as
possible.
Hopefully soon it will all payoff.... ;-)

Regards
Steve.

"Eric R Snow" wrote in message
.. .
On Wed, 2 Jun 2004 13:48:38 +0100, "sme"
wrote:

Dear Group,

I am posting this message in an attempt to gauge interest for a
project I
have been working on.
I have been a hobbyist of metalworking for some time and currently
posses
a
lathe and CNC milling machine which I enjoy the use of very much.
I have also cast metal using traditional foundry methods (gas /
charcoal)
and this is what seeded my interest for this project.

I have designed an induction furnace which is currently in it's
testing
stage.
Initially this furnace was not going to see light of day out side of
my
own
workshop but while demonstrating it to a friend he showed a great deal
of
interest and mentioned that many like minded hobbyists may be
interested
in
such a device.

So I guess I am posting this to gauge interest from the group and seek
advice to what value both from usage and monetary you would put on it.

I would like to apologise in advance if members of this group see this
post
as a form of spam. Please be assured that this is not my intention.
I agree it would be nice to make a little cash out of ones hobby and
give
up
the office job ;-)

Regards,
Steve.

Greetings Steve,
By all means you should post any info you can. There has been much
interest in induction furnaces expressed in this group.
Cheers,
Eric

Machineman, thanks for you reply.
I was looking as 5mm copper tube bent into a coil. Water could then be fed
through this as a cooling agent.
Problem really lies with safety aspects as water in close proximately with
high voltage circuitry .......

Regards
Steve.

"Machineman" wrote in message
...
Have you tried using copper tubing for your coil? I believe this is the
standard type of set up for commercial units, though they probably are
not using plumbing tube, but for a low power unit it may be usable.

sme wrote:

Eric, thanks for the encouragement.

Currently the system can heat 20mm tool steel to yellow / white in about
six
seconds.
I am currently working on the cooling aspect using a closed loop water
supply that flows around the work coil.
The system is running at approx. a third of full power so melting of
steel
should be achievable.
Additional testing and fine tuning of variable frequency is also in the
process.
All circuitry is solid state and is currently cooled by standard PC fans
which will eventually make the unit very compact and transportable.

The circuit boards where designed using Eagle PCB then cut on a CNC
Denford
Starmill (1988) that I was lucky to find going for a song. Incidentally
I
managed to convert this mill to run on Linux EMC patched into its
original
L297 / L298 stepper drivers. The original control circuit could only
hold
approx 32kb of info so this is now bypassed.

This has been a part time project with many trips to the library and
countless hours rambling the web for as much info on induction as
possible.
Hopefully soon it will all payoff.... ;-)

Regards
Steve.

"Eric R Snow" wrote in message
...

On Wed, 2 Jun 2004 13:48:38 +0100, "sme"
wrote:


Dear Group,

I am posting this message in an attempt to gauge interest for a project
I
have been working on.
I have been a hobbyist of metalworking for some time and currently
posses

a

lathe and CNC milling machine which I enjoy the use of very much.
I have also cast metal using traditional foundry methods (gas /
charcoal)
and this is what seeded my interest for this project.

I have designed an induction furnace which is currently in it's testing
stage.
Initially this furnace was not going to see light of day out side of my

own

workshop but while demonstrating it to a friend he showed a great deal
of
interest and mentioned that many like minded hobbyists may be
interested

in

such a device.

So I guess I am posting this to gauge interest from the group and seek
advice to what value both from usage and monetary you would put on it.

I would like to apologise in advance if members of this group see this

post

as a form of spam. Please be assured that this is not my intention.
I agree it would be nice to make a little cash out of ones hobby and
give

up

the office job ;-)

Regards,
Steve.


Greetings Steve,
By all means you should post any info you can. There has been much
interest in induction furnaces expressed in this group.
Cheers,
Eric




--
James P Crombie
Slemon Park, PEI
Canada
Machinist - 3D Cad Design - Amateur Astronomer

http://www.jamescrombie.com

"sme" wrote in message
...
Dear Group,

I am posting this message in an attempt to gauge interest for a project I
have been working on.
I have been a hobbyist of metalworking for some time and currently posses
a
lathe and CNC milling machine which I enjoy the use of very much.
I have also cast metal using traditional foundry methods (gas / charcoal)
and this is what seeded my interest for this project.

I have designed an induction furnace which is currently in it's testing
stage.
Initially this furnace was not going to see light of day out side of my
own
workshop but while demonstrating it to a friend he showed a great deal of
interest and mentioned that many like minded hobbyists may be interested
in
such a device.

So I guess I am posting this to gauge interest from the group and seek
advice to what value both from usage and monetary you would put on it.

I would like to apologise in advance if members of this group see this
post
as a form of spam. Please be assured that this is not my intention.
I agree it would be nice to make a little cash out of ones hobby and give
up
the office job ;-)

Regards,
Steve.



Steve,

Add me to your 'interested' list - induction heating has been a 'must get
round to it someday' back burner project for years. What are you using as
the switching element and what is your upper power limit?

Andrew Mawson
Bromley, Kent, UK

sme wrote:
BoDiddly thanks for your interest,

I think it would not be unreasonable to say that stock of around 30-40mm dia
could be worked.
This could be placed in a small removable crucible of which the work coil
surrounds Eddie currents will then be induced into the workpiece which acts
as a primary single coil (high amps) this causes friction that heats the
piece and eventually melts it.

This setup would be ideal for working on smallish pieces using centrifugal
lost wax casting.
In fact one of the reasons I got interested in induction stemmed from my
interest in micro gas turbines and the wish to cast inconnel turbine blades.

OH, WOW! This is starting to get very interesting! But, what do you use
for a mold? Investment casting?

Jon

Hello Andrew .... A local chap I see.... I to live in Kent UK

Basically this is an off line high power smps (switch mode power supply).

Below is an overview of the process :-
Low voltage oscillator that signals mosfet drivers that switches high power
mosfets that alternates 400vdc into the primary which inducts into the
secondary (low voltage high current) which alternates work coil (lower
voltage higher current) that finally inducts eddie currents into the
workpiece causing friction = heat

Some issues arise from ringing, frequency matching the workpiece, safe
cooling of workcoil, making it safe for public use and finally making it
look sexy. ;-)

Regards
Steve.


"Andrew Mawson" wrote in message
...

"sme" wrote in message
...
Dear Group,

I am posting this message in an attempt to gauge interest for a project
I
have been working on.
I have been a hobbyist of metalworking for some time and currently
posses
a
lathe and CNC milling machine which I enjoy the use of very much.
I have also cast metal using traditional foundry methods (gas /
charcoal)
and this is what seeded my interest for this project.

I have designed an induction furnace which is currently in it's testing
stage.
Initially this furnace was not going to see light of day out side of my
own
workshop but while demonstrating it to a friend he showed a great deal
of
interest and mentioned that many like minded hobbyists may be interested
in
such a device.

So I guess I am posting this to gauge interest from the group and seek
advice to what value both from usage and monetary you would put on it.

I would like to apologise in advance if members of this group see this
post
as a form of spam. Please be assured that this is not my intention.
I agree it would be nice to make a little cash out of ones hobby and
give
up
the office job ;-)

Regards,
Steve.



Steve,

Add me to your 'interested' list - induction heating has been a 'must get
round to it someday' back burner project for years. What are you using as
the switching element and what is your upper power limit?

Andrew Mawson
Bromley, Kent, UK

On Wed, 2 Jun 2004 17:53:01 +0100, "sme"
wrote:

Eric it would be a nice clean table top solution no stoking of coals or use
of gas would not even have to venture outside the workshop.... great for
those winter months :-)

One thing that does concern me is safety.
If I was to sell this (cottage industry style) I could not guarantee the
safe usage or negligence from the user and in the days of ambulance chasing
litigation lawyers I could end up loosing the shirt on my back or worse so I
guess this would need a great deal of thought. Not sure how this lies as
yet!

Regards
Steve.

Well Steve, just don't sell it. Give away the plans along with a
disclaimer that says this is fir info only, not for building, and if
you are stupid enough to build it and burn down the house then tough
beans. But there are all kinds of publications available for sale with
instructions to build various lethal devices so sell it if you want.
Eric

"sme" wrote in message ...
Dear Group,

snip
So I guess I am posting this to gauge interest from the group and seek
advice to what value both from usage and monetary you would put on it.

I would like to apologise in advance if members of this group see this post
as a form of spam. Please be assured that this is not my intention.
I agree it would be nice to make a little cash out of ones hobby and give up
the office job ;-)

Regards,
Steve.


Steve:

By all means, keep us informed! I and most of the other
small-business jewelers I know would LOVE to have an induction melter,
but commercial ones are way out of reach dollar-wise for most of us.
I'd be very interested in a home-brew design, especially one for which
someone else has already worked out the kinks!

Best regards,

Bob

Ok Jon this is a short summary of the process as I understand it ...Most of
this information comes from a very good (excellent) book on this topic
called "Centrifugal or Lost Wax Jewellery Casting" by Murray Bovin.

A shape can be designed using a cad package such as rhino etc etc
This can then be converted to Gcode which can then be processed by Linux EMC
which drives the CNC mill.

Carving wax is mounted and the mill set in motion once completed your
desired part should be replicated in the wax.

This wax part is hung inside a flask(a tube) to be eventually surrounded by
investment.

Investment is composed of cristobalite, gypsum, silicas and modifying
agents.
cristobalite is a volcanic mineral. It is now made by heating silicas to
2680C - 3040C.

One problem with investment is air bubble's the solution is to vacuum them
out by placing the investment inside a bell jar.

The slurry (investment) can then be slowly pored into the flask containing
the wax part once this process is complete burnout can take place. Burnout
removes the wax leaving the impression in the solid dried investment.

This can then be placed in the centrifugal casting machine ready to receive
the molten metal.

Once the metal is in place a pin is pulled sending the clockwork centrifugal
arm rotating which forces the molten metal into the investment. Once cooled
the investment can be removed hopefully leaving the finished part intact.

Note : you could skip the steps of designing and cutting the wax part if you
have a piece to copy by taking an impression of it in rubber then poring
molten wax into the rubber mould. This would give you your lost wax part.
Alternatively you could carve the wax by hand as many Jewellers do or at
least they used to.

Hope this helps Jon forgive me for any unclear rambling ;-)

Regards
Steve




"Jon Elson" wrote in message
...


sme wrote:
BoDiddly thanks for your interest,

I think it would not be unreasonable to say that stock of around 30-40mm
dia
could be worked.
This could be placed in a small removable crucible of which the work
coil
surrounds Eddie currents will then be induced into the workpiece which
acts
as a primary single coil (high amps) this causes friction that heats the
piece and eventually melts it.

This setup would be ideal for working on smallish pieces using
centrifugal
lost wax casting.
In fact one of the reasons I got interested in induction stemmed from my
interest in micro gas turbines and the wish to cast inconnel turbine
blades.

OH, WOW! This is starting to get very interesting! But, what do you use
for a mold? Investment casting?

Jon

Very exciting, could you please supply a schematic?

What kind of resonant capacitors do you use with the work coil?

Tim

--
"I have misplaced my pants." - Homer Simpson | Electronics,
- - - - - - - - - - - - - - - - - - - - - - --+ Metalcasting
and Games: http://webpages.charter.net/dawill/tmoranwms

"sme" wrote in message
...
Dear Group,

I am posting this message in an attempt to gauge interest for a project I
have been working on.
I have been a hobbyist of metalworking for some time and currently posses
a
lathe and CNC milling machine which I enjoy the use of very much.
I have also cast metal using traditional foundry methods (gas / charcoal)
and this is what seeded my interest for this project.

I have designed an induction furnace which is currently in it's testing
stage.
Initially this furnace was not going to see light of day out side of my
own
workshop but while demonstrating it to a friend he showed a great deal of
interest and mentioned that many like minded hobbyists may be interested
in
such a device.

So I guess I am posting this to gauge interest from the group and seek
advice to what value both from usage and monetary you would put on it.

I would like to apologise in advance if members of this group see this
post
as a form of spam. Please be assured that this is not my intention.
I agree it would be nice to make a little cash out of ones hobby and give
up
the office job ;-)

Regards,
Steve.

Tim thank you for your reply...

At this time I would have to decline supplying you with a schematic or in
this case it would be three or four schematics, Sorry.
I am sure you can appreciate there has been a great deal of work put into
this project to date.
Ideally I would like to make this into a commercial viable product that the
likes of you and I, hobbyist / jewellers could afford and feel that we are
getting good value. I should stress at this stage that I am not out to make
a fortune but rather it would be nice to make a living or a small cottage
industry supplying this kit at a price we would all be willing to part with
for such a device.

I initially posted here to try and gauge interest for the purpose to spur me
on to refine the system I guess there's nothing like encouragement which so
far the replies have given.

Saying this circumstances change and if they do I would be more than happy
to supply a schematic to you.

Regards
Steve.


"Tim Williams" wrote in message
...
Very exciting, could you please supply a schematic?

What kind of resonant capacitors do you use with the work coil?

Tim

--
"I have misplaced my pants." - Homer Simpson | Electronics,
- - - - - - - - - - - - - - - - - - - - - - --+ Metalcasting
and Games: http://webpages.charter.net/dawill/tmoranwms

"sme" wrote in message
...
Dear Group,

I am posting this message in an attempt to gauge interest for a project
I
have been working on.
I have been a hobbyist of metalworking for some time and currently
posses
a
lathe and CNC milling machine which I enjoy the use of very much.
I have also cast metal using traditional foundry methods (gas /
charcoal)
and this is what seeded my interest for this project.

I have designed an induction furnace which is currently in it's testing
stage.
Initially this furnace was not going to see light of day out side of my
own
workshop but while demonstrating it to a friend he showed a great deal
of
interest and mentioned that many like minded hobbyists may be interested
in
such a device.

So I guess I am posting this to gauge interest from the group and seek
advice to what value both from usage and monetary you would put on it.

I would like to apologise in advance if members of this group see this
post
as a form of spam. Please be assured that this is not my intention.
I agree it would be nice to make a little cash out of ones hobby and
give
up
the office job ;-)

Regards,
Steve.

Hi Steve
By all means I am interested in learning all you want to teach about your
induction furnace. I have written a couple of books for Lindsay Publications
and there are disclaimers in the front of each book that do a very good job of
covering the legal aspects of a project. This is not to say that someone will
not try to sue you but It does make their chances of success very poor.
Lindsay helped and guided me as I wrote both of my books because he believed
there would be a market for them. I am sure he would be willing to consider
your furnace because there is a real demand for it. Casting ferrous metals is
hard and an induction furnace would be just the ticket. Please keep me on your
list of people to keep informed, I am very interested.
Rick

sme wrote:

Ok Jon this is a short summary of the process as I understand it ...Most of
this information comes from a very good (excellent) book on this topic
called "Centrifugal or Lost Wax Jewellery Casting" by Murray Bovin.


OK, I am familiar with the investment casting concept, You didn't have to go
to such great detail for this, I was just wondering what casting technique
you were going to use. It seems like an exotic thing to be casing in
Inconel!

Thanks,

Jon

Quite interesting!, since its a new design I'm sure you are using IGBTs for
the output circuit, since they have pretty much replaced the SCRs in
induction power supplies. You mentioned you wanted to "keep the design a
secret" but of course you can reveal what frequency and wattage you are
planning to offer it at so we can all get an idea what applications it might
be useful for. I have a Inductotherm VIP 60 in my shop, I replaced the banks
of SCRs with a single high powered SCR for each side. This also allowed me
to remove the dampening circuit on the output transformers, since inrush is
not such a problem with the new ones. I did buy some IGBTs for a induction
project. Since it was just for my own use. I would much rather buy one to
get rid of that cooling tower. Tell us more!
Alan Black
www.sanmartin.com

"sme" wrote in message
...
Tim thank you for your reply...

At this time I would have to decline supplying you with a schematic or in
this case it would be three or four schematics, Sorry.
I am sure you can appreciate there has been a great deal of work put into
this project to date.
Ideally I would like to make this into a commercial viable product that
the
likes of you and I, hobbyist / jewellers could afford and feel that we are
getting good value. I should stress at this stage that I am not out to
make
a fortune but rather it would be nice to make a living or a small cottage
industry supplying this kit at a price we would all be willing to part
with
for such a device.

I initially posted here to try and gauge interest for the purpose to spur
me
on to refine the system I guess there's nothing like encouragement which
so
far the replies have given.

Saying this circumstances change and if they do I would be more than happy
to supply a schematic to you.

Regards
Steve.


"Tim Williams" wrote in message
...
Very exciting, could you please supply a schematic?

What kind of resonant capacitors do you use with the work coil?

Tim

--
"I have misplaced my pants." - Homer Simpson | Electronics,
- - - - - - - - - - - - - - - - - - - - - - --+ Metalcasting
and Games: http://webpages.charter.net/dawill/tmoranwms

"sme" wrote in message
...
Dear Group,

I am posting this message in an attempt to gauge interest for a
project
I
have been working on.
I have been a hobbyist of metalworking for some time and currently
posses
a
lathe and CNC milling machine which I enjoy the use of very much.
I have also cast metal using traditional foundry methods (gas /
charcoal)
and this is what seeded my interest for this project.

I have designed an induction furnace which is currently in it's
testing
stage.
Initially this furnace was not going to see light of day out side of
my
own
workshop but while demonstrating it to a friend he showed a great deal
of
interest and mentioned that many like minded hobbyists may be
interested
in
such a device.

So I guess I am posting this to gauge interest from the group and seek
advice to what value both from usage and monetary you would put on it.

I would like to apologise in advance if members of this group see this
post
as a form of spam. Please be assured that this is not my intention.
I agree it would be nice to make a little cash out of ones hobby and
give
up
the office job ;-)

Regards,
Steve.

sme wrote:

I am sure you can appreciate there has been a great deal of work put into
this project to date.



Having designed smps myself, this has to be the largest understatement
I've heard in awhile.

Sounds like a pretty interesting project.

Steve Smith

How about circulating propylene glycol instead of water, inside a copper
tubing load coil? Nontoxic, basically nonconducting in case of a leak,
and pretty cheap (Sierra antifreeze is about $7/gallon here in the US).
It's a little viscous until it warms up, and doesn't have the heat
capacity of water, but should be safer for you.

--
Regards,
Carl Ijames carl.ijames at verizon.net

--Seems to me you'd be better off making the cooling coil out of
stainless tube, lest you risk a burn-thru of the copper, which melts at a
much lower temp, yes? Better safe than sorry and all that... Heat transfer
sucks big time with stainless compared to copper tho.

--
"Steamboat Ed" Haas : Just another fart in the
Hacking the Trailing Edge! : big Elevator of Life...
http://www.nmpproducts.com/intro.htm
---Decks a-wash in a sea of words---

"steamer" wrote in message
...
--Seems to me you'd be better off making the cooling coil out of
stainless tube, lest you risk a burn-thru of the copper, which melts at a
much lower temp, yes? Better safe than sorry and all that... Heat transfer
sucks big time with stainless compared to copper tho.


Nope! Commercial induction furnaces use copper coils, which are water
cooled. Burn-thru is no problem as long as you don't expose the coils to
the melt, and make sure you have water circulating. The typical induction
furnace has a pressure switch that shuts down the furnace if you lose water
pressure.

Harold

I asked the Inductotherm people about that, they say don't use automotive
type antifreeze, but you can add ethylene glycol to the water in very cold
areas.
Alan Black

"Carl Ijames" wrote in message
...
How about circulating propylene glycol instead of water, inside a copper
tubing load coil? Nontoxic, basically nonconducting in case of a leak,
and pretty cheap (Sierra antifreeze is about $7/gallon here in the US).
It's a little viscous until it warms up, and doesn't have the heat
capacity of water, but should be safer for you.

--
Regards,
Carl Ijames carl.ijames at verizon.net

"Alan Black" wrote in message
m...
I asked the Inductotherm people about that, they say don't use automotive
type antifreeze, but you can add ethylene glycol to the water in very cold
areas.
Alan Black


Auto antifreeze is ethylene glycol. Something doesn't add up! g

Harold

"steamer" wrote in message
...
--Seems to me you'd be better off making the cooling coil out of
stainless tube,

Oh dear me my oh no! Stainless is a very good resistor. We want the heat
in the work, not the coil. G

Tim

--
"I have misplaced my pants." - Homer Simpson | Electronics,
- - - - - - - - - - - - - - - - - - - - - - --+ Metalcasting
and Games: http://webpages.charter.net/dawill/tmoranwms

"sme" wrote in message
...
At this time I would have to decline supplying you with a schematic or in
this case it would be three or four schematics, Sorry.
I am sure you can appreciate there has been a great deal of work put into
this project to date.

Fair enough. Can I ask about the basic topology, namely, does it use
resonance? Quasi-resonance? Is the heating current (reactive and
otherwise) fully handled by the power devices (IGBTs I presume)? Is it a
full wave setup?

Tim

--
"I have misplaced my pants." - Homer Simpson | Electronics,
- - - - - - - - - - - - - - - - - - - - - - --+ Metalcasting
and Games: http://webpages.charter.net/dawill/tmoranwms

"Tim Williams" wrote in message
...
"steamer" wrote in message
...
--Seems to me you'd be better off making the cooling coil out of
stainless tube,

Oh dear me my oh no! Stainless is a very good resistor. We want the heat
in the work, not the coil. G

Tim


Yep. The coil should have low resistance. It's not a heating element,
it's a winding in a transformer of sorts.

Harold

"Harold & Susan Vordos" wrote in message
...

"Tim Williams" wrote in message
...
"steamer" wrote in message
...
--Seems to me you'd be better off making the cooling coil out of
stainless tube,

Oh dear me my oh no! Stainless is a very good resistor. We want the heat
in the work, not the coil. G

Tim


Yep. The coil should have low resistance. It's not a heating element,
it's a winding in a transformer of sorts.

Harold


*Cooling* coil?

"A.Gent" wrote in message
u...

"Harold & Susan Vordos" wrote in message
...

"Tim Williams" wrote in message
...
"steamer" wrote in message
...
--Seems to me you'd be better off making the cooling coil out of
stainless tube,

Oh dear me my oh no! Stainless is a very good resistor. We want the
heat
in the work, not the coil. G

Tim


Yep. The coil should have low resistance. It's not a heating element,
it's a winding in a transformer of sorts.

Harold


*Cooling* coil?

In a sense, yes. Because it lives in such a hot environment (the actual
melting portion of the furnace), it must be cooled. The coil is generally
buried in refractory, so it doesn't see the direct heat of melting, although
it is very close to it.

Harold

"Harold & Susan Vordos" wrote in message
...

"A.Gent" wrote in message
u...
*Cooling* coil?

In a sense, yes. Because it lives in such a hot environment (the actual
melting portion of the furnace), it must be cooled. The coil is generally
buried in refractory, so it doesn't see the direct heat of melting, although
it is very close to it.

Harold



Uh huh.
Thanks.

--
Jeff

Harold,
Oh I know and agree, I bought the unit used and it seemed to have some scale
so I asked about using coolant instead of water. They said not to use
automotive coolant, I did not argue with the experts. This is my first
induction melting unit, I've been bumming time on someone else's 100KW
Pillar and am now forced to learn all about it. I had bought some IGBTs and
was ready to build a microcontroller based unit but I needed something that
I can get up and working in the short term.
BTW what does g mean?
Alan


"Harold & Susan Vordos" wrote in message
...

"Alan Black" wrote in message
m...
I asked the Inductotherm people about that, they say don't use
automotive
type antifreeze, but you can add ethylene glycol to the water in very
cold
areas.
Alan Black


Auto antifreeze is ethylene glycol. Something doesn't add up! g

Harold

The danger is not whether it is conductive or not; it is what happens when
liquid hits molten steel!

Mark

P.S. Harold, we got my Inductotherm running a couple of months ago.



"Harold & Susan Vordos" wrote in message
...

"Alan Black" wrote in message
m...
I asked the Inductotherm people about that, they say don't use
automotive
type antifreeze, but you can add ethylene glycol to the water in very
cold
areas.
Alan Black


Auto antifreeze is ethylene glycol. Something doesn't add up! g

Harold

"Alan Black" wrote in message
news
BTW what does g mean?



See also BG (big grin) and E for evil, etc....

Tim

--
"I have misplaced my pants." - Homer Simpson | Electronics,
- - - - - - - - - - - - - - - - - - - - - - --+ Metalcasting
and Games: http://webpages.charter.net/dawill/tmoranwms

In article ,
Alan Black wrote:

[ ... ]

BTW what does g mean?

The same thing as ":-)". It is indicating that something was
said with a smile (or a grin). The two symbols came from different
groups. The ":-)" (smiley) originated with usenet newsgroups, while I
believe that the "g" (grin) originated with bulletin board systems,
perhaps at about the same time.

Are there any bulletin board systems (the old kind, where
everyone dials in to a central system) still in operation?

Enjoy,
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 ---

"M" mark@maxmachinedotcom wrote in message
...
The danger is not whether it is conductive or not; it is what happens when
liquid hits molten steel!

Mark

P.S. Harold, we got my Inductotherm running a couple of months ago.


That's real good news, Mark! Glad to hear it.

I recall you had a problem with blowing fuses (or tripping breakers) and
were looking to try a soft start switch. Can you tell us how you resolved
the problem?

Harold

Boy, I'd love to hear their explanation for why auto antifreeze is no
good but ethylene glycol is ok. The antifreeze has a lubricant for the
water pump and an anticorrosion package but all that together is less
than 1%, it's all compatible with copper tubing, steel, and cast iron,
and the electrical conductivity is pretty low to avoid problems with
dis-similar metals in the engine and radiator. I just thought the
propylene glycol based antifreeze would be better here since it's
nontoxic. I'm too lazy to look up the flash point but I don't think the
glycols burn much unless there's another source of fuel to keep them
going; even water hitting molten steel is going to be violent enough
that I personally don't think the glycol would be worse, but I've never
done the test ... :-).

--
Regards,
Carl Ijames carl.ijames at verizon.net

"Alan Black" wrote in message
m...
I asked the Inductotherm people about that, they say don't use
automotive
type antifreeze, but you can add ethylene glycol to the water in very
cold
areas.
Alan Black

"Carl Ijames" wrote in message
...
How about circulating propylene glycol instead of water, inside a
copper
tubing load coil? Nontoxic, basically nonconducting in case of a
leak,
and pretty cheap (Sierra antifreeze is about $7/gallon here in the
US).
It's a little viscous until it warms up, and doesn't have the heat
capacity of water, but should be safer for you.

--
Regards,
Carl Ijames carl.ijames at verizon.net

Hi Harold...

We finally wound up using 24 5000 watt dryer elements in series with the
motor, which limited the starting current to 100 amps at 440 volts... the
heaters radiate about 45,000 watts for about 30 seconds until the motor
comes up to speed then go dark. They are then switched out of the circuit.
Takes the chill out of the foundry right away! They are mounted overhead
for safety... think of a SERIOUS infrared heater mounted to the ceiling...

There is a talented high school student named Trevor that is doing most of
the hard work on this project. I am sure that he will be one of those
people that we'll say "I knew him when..."

Mark




"Harold & Susan Vordos" wrote in message
...

"M" mark@maxmachinedotcom wrote in message
...
The danger is not whether it is conductive or not; it is what happens
when
liquid hits molten steel!

Mark

P.S. Harold, we got my Inductotherm running a couple of months ago.


That's real good news, Mark! Glad to hear it.

I recall you had a problem with blowing fuses (or tripping breakers) and
were looking to try a soft start switch. Can you tell us how you
resolved
the problem?

Harold

Hi Harold...

We finally wound up using 24 5000 watt dryer elements in series with the
motor, which limited the starting current to 100 amps at 440 volts... the
heaters radiate about 45,000 watts for about 30 seconds until the motor
comes up to speed then go dark. They are then switched out of the circuit.
Takes the chill out of the foundry right away! They are mounted overhead
for safety... think of a SERIOUS infrared heater mounted to the ceiling...

There is a talented high school student named Trevor that is doing most of
the hard work on this project. I am sure that he will be one of those
people that we'll say "I knew him when..."

Mark





"Harold & Susan Vordos" wrote in message
...

"M" mark@maxmachinedotcom wrote in message
...
The danger is not whether it is conductive or not; it is what happens
when
liquid hits molten steel!

Mark

P.S. Harold, we got my Inductotherm running a couple of months ago.


That's real good news, Mark! Glad to hear it.

I recall you had a problem with blowing fuses (or tripping breakers) and
were looking to try a soft start switch. Can you tell us how you
resolved
the problem?

Harold