View Full Version : diy spot welder

12-19-2005, 07:06 AM
David, I saw the pic of your spot welder in another thread, its something i'd like to build.....so does the gang have any words of wisdom or particularly good tutorials/build sites out there you know of?

12-19-2005, 10:06 AM
That is a $159.00 Harbor Freight Spot welder, converted with a 8" stroke cylinder, a opto22 power-cube timer controlled by the Cnc mill computer.

Footswitch activated according to Visual basic software. *press 1. or welder or press 2

There is no reason it has to be that complicated.

running between 2500 and 3500 microseconds per weld on the stainless.. so some timer that hits close is allright. (1.5-5 seconds)

Operational logic?
foot pedal?
1)It clamps air solonoid
2)timer to close and build pressure.. wait...
3)turns on opto-cube relay,
4) timer weld-time.. wait..
5) turns off welder
6) hold closed air till foot-pedal releases

You can build the same with cube relay, two timers, pneumatic solonoid and a foot switch plus a 3-24vdc source for solonoids and cube relay. No computer needed.

I have seen cycle timers that would do all this.. they are motor driven sequence relays.

I can not see, manipulating two sheetmetal pieces in place, holding the "heavy" spot welder, clamping down the lever with your "other hand" and then working the switch for a exact time period to make a perfect weld. It was just too hard on a fat boy.. so.. I automated mine. I love the easy button. My welder hangs on a arm and I hold the parts and step on the pedal.

12-19-2005, 11:13 AM
Linsy Publication is a good place to start. I have made three from there ideas by taking high voltage transformer cutting the secondary high side off and putting layers of sheet aluminum to makeup a new secondary with only two raps around transformer.


12-19-2005, 11:20 AM
First you start with one of these:


Unfortunately, that's as far as I have gotten so far... http://bbs.homeshopmachinist.net//biggrin.gif

12-19-2005, 11:57 AM
Ohh, you want to build one, not automate.

A online pdf. I saved it in my cdrom library somewhere. I'll look in a bit.

I keep threatening to catalog them. Thousands of pdfs. Yeah, I should number them and make a catalog cd. Information is only useful if you use it.

12-19-2005, 05:03 PM
"Information is only useful if you use it."

Or can find it http://bbs.homeshopmachinist.net//smile.gif

I have this book, PC PHD, shows all kinds of neato stuff with the PC, how to autmoate things, etc....I can't find the damn thing.


12-19-2005, 05:37 PM