Under construction:
A tip of the hat to Adam Parker for this simple but elegant device.
What's wrong buddy ... fusor trash your wallet?
Ebay wants 300 dollars for a spot welder?
How about free?
That's right free for a limited time only!
It's real simple for a person willing to get their hands dirty for about 30 minutes.
Just take a MOT and cut away the secondary and clean out the top holes while leaving the primary alone.
Replace the fine wire secondary with a four turns #8 house wire.
Use a low voltage relay to control power to the wired xformer. Control it with a foot switch... Press to weld.
So far Ok ... it will work like this but if you want fine control put a variac in front of the relay .
Since Alan did the brow sweat on the guts of the beast , I made it extremely easy to do.
Only three tools a Large flat blade screw driver, a drill, and most inportantly a saber saw with the base foot removed. Another barrier to fusion falls.
Fusion is fun dig it!
Larry Leins
Fusion Tech
30 seconds to spot welder
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guest
Re: 30 seconds to spot welder Pict #3
Pushing is futile use the drill... most mots are dipped in insulative liquid.
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Re: 30 seconds to spot welder
Hey Larry,
Great to hear the spot welder endeavor is going well, although I can't take absolute credit for the idea. To give credit where credit is due, search way back on the old "Songs" archives to see the basic concept mentioned.
I was, however, surprised how well mine worked considering the crudeness of construction. The variac will actually give a pretty good wire size range as far as stainless steel goes. I have not tried it with any other metals.
I know Richard Hull highly recommends the proper electrodes (I believe they are phosphor doped copper?), but I have had good results with just regular old plumber's copper. I use 1" copper pipe for the anvil and quarter inch refrigerator tubing (bent into a tip) for the wand. I used a very light duty variac (about 2amps) for control, but never let the welder stay on more than one second at a time. Having a relay to turn it on is probably a good thing. I yanked a high current relay from an old industrial heater i found on the side of the road.
Good luck in your welding efforts. As a general message, try not to get discouraged if you don't get good welds at first. It takes time get the self taught technique and home made equipment refined.
Adam Parker
Great to hear the spot welder endeavor is going well, although I can't take absolute credit for the idea. To give credit where credit is due, search way back on the old "Songs" archives to see the basic concept mentioned.
I was, however, surprised how well mine worked considering the crudeness of construction. The variac will actually give a pretty good wire size range as far as stainless steel goes. I have not tried it with any other metals.
I know Richard Hull highly recommends the proper electrodes (I believe they are phosphor doped copper?), but I have had good results with just regular old plumber's copper. I use 1" copper pipe for the anvil and quarter inch refrigerator tubing (bent into a tip) for the wand. I used a very light duty variac (about 2amps) for control, but never let the welder stay on more than one second at a time. Having a relay to turn it on is probably a good thing. I yanked a high current relay from an old industrial heater i found on the side of the road.
Good luck in your welding efforts. As a general message, try not to get discouraged if you don't get good welds at first. It takes time get the self taught technique and home made equipment refined.
Adam Parker
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guest
Re: 30 seconds to spot welder Pict #4
hi all
do you leave the shunts in place i was assuming you do
cheers
colin
do you leave the shunts in place i was assuming you do
cheers
colin
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guest
Re: 30 seconds to spot welder Pict #4
All that is left standing is the primary coil.
Take care not to nick it.
But if you do scratch the insulative coat off use nail polish to fix it.
Clear away all copper debris before powering it up.
Be careful although the mot has been neuterded so to speak It still can bite hard. Do not run the new secondary for more than 30 seconds at a time the #8
gets toasty.
Fusion is fun!
Larry Leins
Fusion Tech
Take care not to nick it.
But if you do scratch the insulative coat off use nail polish to fix it.
Clear away all copper debris before powering it up.
Be careful although the mot has been neuterded so to speak It still can bite hard. Do not run the new secondary for more than 30 seconds at a time the #8
gets toasty.
Fusion is fun!
Larry Leins
Fusion Tech
Re: 30 seconds to spot welder
Nice job Larry - thanks for sharing your work. Do you have any idea what the max secondary current can be?
One alternative to the variac is to use a capacitor in series to limit current. Just have to watch out for series resonance. Also need to use caps suitable for AC. Polyester film, or oil filled are good.
Dave Cooper
One alternative to the variac is to use a capacitor in series to limit current. Just have to watch out for series resonance. Also need to use caps suitable for AC. Polyester film, or oil filled are good.
Dave Cooper
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guest
Re: 30 seconds to spot welder
It is well over 600 amps current!
It pegs my clamp on ammeter...its highest scale is 600
amps.
I didn't need much else but training to keep the wire that is being welded from burning up.
Series resonant stuff is difficult to predict but the variac
altho not cheap is pretty easy to use.
The wheels have turned on other uses for these free transformers.
Larry Leins
Fusion Tech
It pegs my clamp on ammeter...its highest scale is 600
amps.
I didn't need much else but training to keep the wire that is being welded from burning up.
Series resonant stuff is difficult to predict but the variac
altho not cheap is pretty easy to use.
The wheels have turned on other uses for these free transformers.
Larry Leins
Fusion Tech