Greetings All,
I haven't posted or read any newsgroups for a long time. I am still
finishing up my house and it has been really all consuming. Anyway, I
know that there are a few folks here who have a Lincoln SP125 Plus
welder. I added a purge button to mine a while ago and it is a big
help. Saves wire and time. It would have been simple to use just a
switch to actuate the gas solenoid but the solenoid is a 125 volt unit
and I wanted to only switch low voltage. So instead I figured out how
to use the low voltage circuitry that the welder uses. I'm sure that
there is a better way but since my knowledge of electronics is so
limited it is what it is. I sent the circuit changes and the scanned
schematic to the dropbox a few minutes ago. Look for files beginning
with SP125+. After I made the changes I coated the circuit board with
epoxy in the areas where I had to remove the conformal coating. It's
important to prevent any conductive dust from shorting anything. I
hope this is useful to someone. Please feel free to tell me how it
could have been done better.
Cheers,
Eric R Snow

On Wed, 30 Apr 2008 02:06:44 GMT, wrote:

Greetings All,
I haven't posted or read any newsgroups for a long time. I am still
finishing up my house and it has been really all consuming. Anyway, I
know that there are a few folks here who have a Lincoln SP125 Plus
welder. I added a purge button to mine a while ago and it is a big
help. Saves wire and time. It would have been simple to use just a
switch to actuate the gas solenoid but the solenoid is a 125 volt unit
and I wanted to only switch low voltage. So instead I figured out how
to use the low voltage circuitry that the welder uses. I'm sure that
there is a better way but since my knowledge of electronics is so
limited it is what it is. I sent the circuit changes and the scanned
schematic to the dropbox a few minutes ago. Look for files beginning
with SP125+. After I made the changes I coated the circuit board with
epoxy in the areas where I had to remove the conformal coating. It's
important to prevent any conductive dust from shorting anything. I
hope this is useful to someone. Please feel free to tell me how it
could have been done better.
Cheers,
Eric R Snow

They may not have arrived yet.

You may get lots of advice about how you could have done it better --
most from those who haven't done it at all. I sure won't argue with
"done" and "works"!

Good move re-coating areas from which you removed conformal coating.
For future reference: epoxy can cause problems but you'd know it by
now if you had a problem. A more compliant material like a urethane
or silicone may place less post-cure mechanical stress on potted or
coated electronic parts. That said, I've used plenty of epoxy without
any problems.

Hey Eric,

Nice to see your name again. It has been some time!! I do understand
the bit about "the house" though. Welcome to the club!!

Regards your drop-box submission, I get the text up OK, but the TIF
seems empty.

I have a similar MIG, and just wonder what the purpose of your mod is.
Purge? I always think that is a way to clear former gases, but maybe
you are suggesting that you fill the torch line with pressure prior to
the arc starting the gas flow. Is that it?

Take care.

Brian Lawson,
Bothwell, Ontario.
XXXXXXXXXXXXXX


On Wed, 30 Apr 2008 02:06:44 GMT, wrote:

Greetings All,
I haven't posted or read any newsgroups for a long time. I am still
finishing up my house and it has been really all consuming. Anyway, I
know that there are a few folks here who have a Lincoln SP125 Plus
welder. I added a purge button to mine a while ago and it is a big
help. Saves wire and time. It would have been simple to use just a
switch to actuate the gas solenoid but the solenoid is a 125 volt unit
and I wanted to only switch low voltage. So instead I figured out how
to use the low voltage circuitry that the welder uses. I'm sure that
there is a better way but since my knowledge of electronics is so
limited it is what it is. I sent the circuit changes and the scanned
schematic to the dropbox a few minutes ago. Look for files beginning
with SP125+. After I made the changes I coated the circuit board with
epoxy in the areas where I had to remove the conformal coating. It's
important to prevent any conductive dust from shorting anything. I
hope this is useful to someone. Please feel free to tell me how it
could have been done better.
Cheers,
Eric R Snow

I have a similar MIG, and just wonder what the purpose of your mod is.
Purge? I always think that is a way to clear former gases, but maybe
you are suggesting that you fill the torch line with pressure prior to
the arc starting the gas flow. Is that it?

Sounds like Eric has the solution to a problem I just live with. If you set
the MIG gun down for more than a short break, the first bit of welding will
just burn up and look like chicken s^&*. I guess there's a reason for
shielding gas.

Karl

On Wed, 30 Apr 2008 02:07:16 -0400, Brian Lawson
wrote:
Greetings Brian,
I don't know why the tif would be empty. I'll check it and see if
maybe I can re send it. I got the original schematic from the Lincoln
web site but cannot find it now. As for the purge, it just makes sure
that there is shielding gas instead of air present at the weld when
welding starts. I had to run wire out and snip it off before I made
the change. It sucks to have porosity in a weld and it happens when
you wait too long between trigger pulls.
ERS

Hey Eric,

Nice to see your name again. It has been some time!! I do understand
the bit about "the house" though. Welcome to the club!!

Regards your drop-box submission, I get the text up OK, but the TIF
seems empty.

I have a similar MIG, and just wonder what the purpose of your mod is.
Purge? I always think that is a way to clear former gases, but maybe
you are suggesting that you fill the torch line with pressure prior to
the arc starting the gas flow. Is that it?

Take care.

Brian Lawson,
Bothwell, Ontario.
XXXXXXXXXXXXXX


On Wed, 30 Apr 2008 02:06:44 GMT, wrote:

Greetings All,
I haven't posted or read any newsgroups for a long time. I am still
finishing up my house and it has been really all consuming. Anyway, I
know that there are a few folks here who have a Lincoln SP125 Plus
welder. I added a purge button to mine a while ago and it is a big
help. Saves wire and time. It would have been simple to use just a
switch to actuate the gas solenoid but the solenoid is a 125 volt unit
and I wanted to only switch low voltage. So instead I figured out how
to use the low voltage circuitry that the welder uses. I'm sure that
there is a better way but since my knowledge of electronics is so
limited it is what it is. I sent the circuit changes and the scanned
schematic to the dropbox a few minutes ago. Look for files beginning
with SP125+. After I made the changes I coated the circuit board with
epoxy in the areas where I had to remove the conformal coating. It's
important to prevent any conductive dust from shorting anything. I
hope this is useful to someone. Please feel free to tell me how it
could have been done better.
Cheers,
Eric R Snow

On Tue, 29 Apr 2008 23:50:44 -0500, Don Foreman
wrote:

Greetings Don,
I didn't know epoxy would pull when curing. Thanks for the heads up. I
thought about silicone but all I had on hand was the stuff with acetic
acid in it and it corrodes stuff while curing sometimes.
ERS
On Wed, 30 Apr 2008 02:06:44 GMT, wrote:

Greetings All,
I haven't posted or read any newsgroups for a long time. I am still
finishing up my house and it has been really all consuming. Anyway, I
know that there are a few folks here who have a Lincoln SP125 Plus
welder. I added a purge button to mine a while ago and it is a big
help. Saves wire and time. It would have been simple to use just a
switch to actuate the gas solenoid but the solenoid is a 125 volt unit
and I wanted to only switch low voltage. So instead I figured out how
to use the low voltage circuitry that the welder uses. I'm sure that
there is a better way but since my knowledge of electronics is so
limited it is what it is. I sent the circuit changes and the scanned
schematic to the dropbox a few minutes ago. Look for files beginning
with SP125+. After I made the changes I coated the circuit board with
epoxy in the areas where I had to remove the conformal coating. It's
important to prevent any conductive dust from shorting anything. I
hope this is useful to someone. Please feel free to tell me how it
could have been done better.
Cheers,
Eric R Snow

They may not have arrived yet.

You may get lots of advice about how you could have done it better --
most from those who haven't done it at all. I sure won't argue with
"done" and "works"!

Good move re-coating areas from which you removed conformal coating.
For future reference: epoxy can cause problems but you'd know it by
now if you had a problem. A more compliant material like a urethane
or silicone may place less post-cure mechanical stress on potted or
coated electronic parts. That said, I've used plenty of epoxy without
any problems.

What's that Lassie? You say that fell down the old
rec.crafts.metalworking mine and will die if we don't mount a rescue
by Wed, 30 Apr 2008 02:06:44 GMT:

snip
Anyway, I
know that there are a few folks here who have a Lincoln SP125 Plus
welder. I added a purge button to mine a while ago and it is a big
help. Saves wire and time.
snip
Eric R Snow

I had thought about doing that to mine too. I was thing of adding a
second switch to the torch, that would trigger the gas valve.

Then I thought of adding a small reservoir and a very low pressure
switch. The torch switch would open the gas valve, and when pressure
has built up, the pressure switch would trigger the welder.

But then I just decided to go easy on the drive roller pressure, and
purge the lines by holding the wire back with my gloved hand.
--

Dan

This is a coincidence...I just posted a link on this very thing
(except for a Miller 175) on HSM just a few days ago. Here's the
link:

http://bullfire.net/WP_Welder.html


On Apr 29, 9:06*pm, wrote:
Greetings All,
I haven't posted or read any newsgroups for a long time. I am still
finishing up my house and it has been really all consuming. Anyway, I
know that there are a few folks here who have a Lincoln SP125 Plus
welder. I added a purge button to mine a while ago and it *is a big
help. Saves wire and time. It would have been simple to use just a
switch to actuate the gas solenoid but the solenoid is a 125 volt unit
and I wanted to only switch low voltage. So instead I figured out how
to use the low voltage circuitry that the welder uses. I'm sure that
there is a better way but since my knowledge of electronics is so
limited it is what it is. I sent the circuit changes and the scanned
schematic to the dropbox a few minutes ago. Look for files beginning
with SP125+. After I made the changes I coated the circuit board with
epoxy in the areas where I had to remove the conformal coating. It's
important to prevent any conductive dust from shorting anything. *I
hope this is useful to someone. Please feel free to tell me how it
could have been done better.
Cheers,
Eric R Snow

wrote:
Greetings All,
I haven't posted or read any newsgroups for a long time. I am still
finishing up my house and it has been really all consuming. Anyway, I
know that there are a few folks here who have a Lincoln SP125 Plus
welder. I added a purge button to mine a while ago and it is a big
help. Saves wire and time. It would have been simple to use just a
switch to actuate the gas solenoid but the solenoid is a 125 volt unit
and I wanted to only switch low voltage. So instead I figured out how
to use the low voltage circuitry that the welder uses. I'm sure that
there is a better way but since my knowledge of electronics is so
limited it is what it is. I sent the circuit changes and the scanned
schematic to the dropbox a few minutes ago. Look for files beginning
with SP125+. After I made the changes I coated the circuit board with
epoxy in the areas where I had to remove the conformal coating. It's
important to prevent any conductive dust from shorting anything. I
hope this is useful to someone. Please feel free to tell me how it
could have been done better.
Cheers,
Eric R Snow
Hi Eric,
I looked at the schematic and your explanation and you did a good job
with it. You protected the other functions of the welder from the purge
button operation. The current through the opto is in a good range.
that's about all you need to do for this one.

I'm glad to see you posting again, you often have interesting stuff to
say or ask.

Take Care,
BobH

On Thu, 01 May 2008 03:12:28 GMT, BobH
wrote:

Thanks Bob, it's good to know that the circuit might work for someone
else.
Cheers,
Eric

wrote:
Greetings All,
I haven't posted or read any newsgroups for a long time. I am still
finishing up my house and it has been really all consuming. Anyway, I
know that there are a few folks here who have a Lincoln SP125 Plus
welder. I added a purge button to mine a while ago and it is a big
help. Saves wire and time. It would have been simple to use just a
switch to actuate the gas solenoid but the solenoid is a 125 volt unit
and I wanted to only switch low voltage. So instead I figured out how
to use the low voltage circuitry that the welder uses. I'm sure that
there is a better way but since my knowledge of electronics is so
limited it is what it is. I sent the circuit changes and the scanned
schematic to the dropbox a few minutes ago. Look for files beginning
with SP125+. After I made the changes I coated the circuit board with
epoxy in the areas where I had to remove the conformal coating. It's
important to prevent any conductive dust from shorting anything. I
hope this is useful to someone. Please feel free to tell me how it
could have been done better.
Cheers,
Eric R Snow
Hi Eric,
I looked at the schematic and your explanation and you did a good job
with it. You protected the other functions of the welder from the purge
button operation. The current through the opto is in a good range.
that's about all you need to do for this one.

I'm glad to see you posting again, you often have interesting stuff to
say or ask.

Take Care,
BobH

"dan" wrote in message
...
What's that Lassie? You say that fell down the old
rec.crafts.metalworking mine and will die if we don't mount a rescue
by Wed, 30 Apr 2008 02:06:44 GMT:

snip
Anyway, I
know that there are a few folks here who have a Lincoln SP125 Plus
welder. I added a purge button to mine a while ago and it is a big
help. Saves wire and time.
snip
Eric R Snow

I had thought about doing that to mine too. I was thing of adding a
second switch to the torch, that would trigger the gas valve.

Then I thought of adding a small reservoir and a very low pressure
switch. The torch switch would open the gas valve, and when pressure
has built up, the pressure switch would trigger the welder.

But then I just decided to go easy on the drive roller pressure, and
purge the lines by holding the wire back with my gloved hand.
--

Dan

Just curious here. I have a Lincoln 175 SP Plus. What is it with a 125
that putting a purge button does? I seem not to have any problem with my
175.

Steve

On May 1, 1:55 am, "SteveB" toquerville,utah@zionvistas wrote:
"dan" wrote in message

...



What's that Lassie? You say that fell down the old
rec.crafts.metalworking mine and will die if we don't mount a rescue
by Wed, 30 Apr 2008 02:06:44 GMT:

snip
Anyway, I
know that there are a few folks here who have a Lincoln SP125 Plus
welder. I added a purge button to mine a while ago and it is a big
help. Saves wire and time.
snip
Eric R Snow

I had thought about doing that to mine too. I was thing of adding a
second switch to the torch, that would trigger the gas valve.

Then I thought of adding a small reservoir and a very low pressure
switch. The torch switch would open the gas valve, and when pressure
has built up, the pressure switch would trigger the welder.

But then I just decided to go easy on the drive roller pressure, and
purge the lines by holding the wire back with my gloved hand.
--

Dan

Just curious here. I have a Lincoln 175 SP Plus. What is it with a 125
that putting a purge button does? I seem not to have any problem with my
175.

Steve



You're welding. You stop for a few seconds, then start again. Start of
the weld is perfect (if you're not me).

But, stop for a longer time, and the shielding gas in the hose near
the torch tip mixes with air, and after a long enough time there's
enough O2 in the line that when you start welding, the first little
bit of weld doesn't get shielded at all, and comes out like crap. The
purge valve lets you run shielding gas out the hose to get rid of any
air in the hose. You could do this by just pulling the trigger, but
then you have to clip off the wasted wire.


Dave

Hey Eric,

Nice to see your name again. It has been some time!! I do understand
the bit about "the house" though. Welcome to the club!!

Regards your drop-box submission, I get the text up OK, but the TIF
seems empty.

I have a similar MIG, and just wonder what the purpose of your mod is.
Purge? I always think that is a way to clear former gases, but maybe
you are suggesting that you fill the torch line with pressure prior to
the arc starting the gas flow. Is that it?

Take care.

Brian Lawson,
Bothwell, Ontario.
XXXXXXXXXXXXXX


On Wed, 30 Apr 2008 02:06:44 GMT, wrote:

Greetings All,
I haven't posted or read any newsgroups for a long time. I am still
finishing up my house and it has been really all consuming. Anyway, I
know that there are a few folks here who have a Lincoln SP125 Plus
welder. I added a purge button to mine a while ago and it is a big
help. Saves wire and time. It would have been simple to use just a
switch to actuate the gas solenoid but the solenoid is a 125 volt unit
and I wanted to only switch low voltage. So instead I figured out how
to use the low voltage circuitry that the welder uses. I'm sure that
there is a better way but since my knowledge of electronics is so
limited it is what it is. I sent the circuit changes and the scanned
schematic to the dropbox a few minutes ago. Look for files beginning
with SP125+. After I made the changes I coated the circuit board with
epoxy in the areas where I had to remove the conformal coating. It's
important to prevent any conductive dust from shorting anything. I
hope this is useful to someone. Please feel free to tell me how it
could have been done better.
Cheers,
Eric R Snow

wrote

You're welding. You stop for a few seconds, then start again. Start of
the weld is perfect (if you're not me).

But, stop for a longer time, and the shielding gas in the hose near
the torch tip mixes with air, and after a long enough time there's
enough O2 in the line that when you start welding, the first little
bit of weld doesn't get shielded at all, and comes out like crap. The
purge valve lets you run shielding gas out the hose to get rid of any
air in the hose. You could do this by just pulling the trigger, but
then you have to clip off the wasted wire.


Dave

Thought that was the situation. Guess I don't stop enough to have that
problem. I get stuff set up, then weld, and it doesn't have time to run
out.

Steve

wrote in message
...
Greetings All,
I haven't posted or read any newsgroups for a long time. I am still
finishing up my house and it has been really all consuming. Anyway, I
know that there are a few folks here who have a Lincoln SP125 Plus
welder. I added a purge button to mine a while ago and it is a big
help. Saves wire and time. It would have been simple to use just a
switch to actuate the gas solenoid but the solenoid is a 125 volt unit
and I wanted to only switch low voltage. So instead I figured out how
to use the low voltage circuitry that the welder uses. I'm sure that
there is a better way but since my knowledge of electronics is so
limited it is what it is. I sent the circuit changes and the scanned
schematic to the dropbox a few minutes ago. Look for files beginning
with SP125+. After I made the changes I coated the circuit board with
epoxy in the areas where I had to remove the conformal coating. It's
important to prevent any conductive dust from shorting anything. I
hope this is useful to someone. Please feel free to tell me how it
could have been done better.
Cheers,
Eric R Snow

I would think a wire feed button would be more useful. My Panasonic 260 has
one on it but on my old Lincoln SP100 I just left the gas off when feeding a
new spool to the gun.
Steve