I've had several queries concerning my spot welder project. The below
pics show a spot welder upgraded to include a weld timer and a power
control.

The timer is just a timer relay set to tenths of a second. It is wired
delay off and closes the power relay seen in pic 1. The switch on the
spot welder itself is wired back to the timer. The power control is a
pair of variacs (free from Pete) on a common shaft. the dial can be
seen in pic 2

Thanks for all the help.

Karl

http://www.mwdropbox.com/dropbox/Spotweld1.jpg
http://www.mwdropbox.com/dropbox/Spotweld2.jpg
http://www.mwdropbox.com/dropbox/Spotweld3.jpg

Karl Townsend wrote:

I've had several queries concerning my spot welder project. The below
pics show a spot welder upgraded to include a weld timer and a power
control.

The timer is just a timer relay set to tenths of a second. It is wired
delay off and closes the power relay seen in pic 1. The switch on the
spot welder itself is wired back to the timer. The power control is a
pair of variacs (free from Pete) on a common shaft. the dial can be
seen in pic 2

Thanks for all the help.

Karl

http://www.mwdropbox.com/dropbox/Spotweld1.jpg
http://www.mwdropbox.com/dropbox/Spotweld2.jpg
http://www.mwdropbox.com/dropbox/Spotweld3.jpg

Very nice, how does it work? Does the power control help on thin
sheetmetal? Some sample weld pics? I've got to get one of those spot
welders the next time I've got a 20% coupon. I probably wouldn't use it
too often, but for the odd bit of shetmetal work I bet it would be
invaluable.

Very nice, how does it work? Does the power control help on thin
sheetmetal? Some sample weld pics? I've got to get one of those spot
welders the next time I've got a 20% coupon. I probably wouldn't use it
too often, but for the odd bit of shetmetal work I bet it would be
invaluable.

I am extremely pleased with the weld on thin stuff. That was the
motivation this. 40 thou stock would just burn a hole, I got great
welds with it set to 180 volt and 2.7 sec on this material.

Pics of welded scrap wouldn't show much. I'll try to take a pic of
rails welded in AK47 or MG42 when i do the project. This was the
project to do the project.

Karl

Karl Townsend wrote:

Very nice, how does it work? Does the power control help on thin
sheetmetal? Some sample weld pics? I've got to get one of those spot
welders the next time I've got a 20% coupon. I probably wouldn't use it
too often, but for the odd bit of shetmetal work I bet it would be
invaluable.

I am extremely pleased with the weld on thin stuff. That was the
motivation this. 40 thou stock would just burn a hole, I got great
welds with it set to 180 volt and 2.7 sec on this material.

Pics of welded scrap wouldn't show much. I'll try to take a pic of
rails welded in AK47 or MG42 when i do the project. This was the
project to do the project.

Karl

Sounds interesting, would like to see.

Have you done one of these yet? http://wpnet.us/jack_screws.jpg

On Sun, 28 Oct 2012 19:54:23 -0500, "Pete C."
wrote:


Karl Townsend wrote:

Very nice, how does it work? Does the power control help on thin
sheetmetal? Some sample weld pics? I've got to get one of those spot
welders the next time I've got a 20% coupon. I probably wouldn't use it
too often, but for the odd bit of shetmetal work I bet it would be
invaluable.

I am extremely pleased with the weld on thin stuff. That was the
motivation this. 40 thou stock would just burn a hole, I got great
welds with it set to 180 volt and 2.7 sec on this material.

Pics of welded scrap wouldn't show much. I'll try to take a pic of
rails welded in AK47 or MG42 when i do the project. This was the
project to do the project.

Karl

Sounds interesting, would like to see.

Have you done one of these yet? http://wpnet.us/jack_screws.jpg

I bought some of the AR15 forgings but haven't machined them. "The
Kid" has an FFL so he buys complete lowers very inexpensively. Still,
this would be a fun project.

Is the guy in that pic machining the part just clamped with scrap and
Kant twist clamps??? I'd build custom softjaws for each op if i were
doing it, then knock out at least 25 units on the CNC.

Karl

Karl Townsend wrote:

On Sun, 28 Oct 2012 19:54:23 -0500, "Pete C."
wrote:


Karl Townsend wrote:

Very nice, how does it work? Does the power control help on thin
sheetmetal? Some sample weld pics? I've got to get one of those spot
welders the next time I've got a 20% coupon. I probably wouldn't use it
too often, but for the odd bit of shetmetal work I bet it would be
invaluable.

I am extremely pleased with the weld on thin stuff. That was the
motivation this. 40 thou stock would just burn a hole, I got great
welds with it set to 180 volt and 2.7 sec on this material.

Pics of welded scrap wouldn't show much. I'll try to take a pic of
rails welded in AK47 or MG42 when i do the project. This was the
project to do the project.

Karl

Sounds interesting, would like to see.

Have you done one of these yet? http://wpnet.us/jack_screws.jpg

I bought some of the AR15 forgings but haven't machined them. "The
Kid" has an FFL so he buys complete lowers very inexpensively. Still,
this would be a fun project.

Is the guy in that pic machining the part just clamped with scrap and
Kant twist clamps??? I'd build custom softjaws for each op if i were
doing it, then knock out at least 25 units on the CNC.

Karl

Scrap and Kant-Twist, with a couple jack screws for extra support. No
issues on a manual mill. The only CNC mill I have at the moment is a
converted mini mill which does a nice job engraving the selector and my
logo, but doesn't have the HP/travel/accuracy to do the real work. At
any rate it takes a day and a half to do one, a long day machining, then
half the next for CNC engraving and anodizing.

On 2012-10-28, Karl Townsend wrote:
I've had several queries concerning my spot welder project. The below
pics show a spot welder upgraded to include a weld timer and a power
control.

The timer is just a timer relay set to tenths of a second. It is wired
delay off and closes the power relay seen in pic 1. The switch on the
spot welder itself is wired back to the timer. The power control is a
pair of variacs (free from Pete) on a common shaft. the dial can be
seen in pic 2

Looks nice -- but I have one question. As it is shown, it is
set for 2.7 seconds, which is fine. But how small a time do you expect
as your minimum? The reason I ask is that I wonder what the mechanical
delay time on the relay is. I would be tempted to use a solid state
relay instead for more precise control of time (down to 1/120th of a
second, and then fractions thereof depending on when the relay is turned
on relative to the power line cycles.

If you don't expect to go much below one second, you should be
fine with it as it is.

Can you read the lines on that timer? I've got no idea what
they say. (Nor am I sure what the leading "89" and the 'H' mean in the
switches.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
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 ---

On 29 Oct 2012 00:41:53 GMT, "DoN. Nichols"
wrote:

On 2012-10-28, Karl Townsend wrote:
I've had several queries concerning my spot welder project. The below
pics show a spot welder upgraded to include a weld timer and a power
control.

The timer is just a timer relay set to tenths of a second. It is wired
delay off and closes the power relay seen in pic 1. The switch on the
spot welder itself is wired back to the timer. The power control is a
pair of variacs (free from Pete) on a common shaft. the dial can be
seen in pic 2

Looks nice -- but I have one question. As it is shown, it is
set for 2.7 seconds, which is fine. But how small a time do you expect
as your minimum? The reason I ask is that I wonder what the mechanical
delay time on the relay is. I would be tempted to use a solid state
relay instead for more precise control of time (down to 1/120th of a
second, and then fractions thereof depending on when the relay is turned
on relative to the power line cycles.

If you don't expect to go much below one second, you should be
fine with it as it is.

Can you read the lines on that timer? I've got no idea what
they say. (Nor am I sure what the leading "89" and the 'H' mean in the
switches.

Enjoy,
DoN.

I should be able to just turn the power down to keep weld times
higher. The timer relay I scored is one of the multifunction units. In
the pic it is set to cycle on for 2.7 sec once every 89 Hours. The H
is for hours. The 2.7 is set to tenths of a second. It was an eBay
special for $5.

Karl