How to convert scavenged microwave parts into a useful arc welding machine.  This is part 1 of 2, and focuses on the modification of the transformers.


Step 1: Watch the Video!

WARNING: Stick welding, and/or the modification of a Microwave Oven Transformer (M.O.T), can be very dangerous and presents risks of UV radiation, shock hazards, burns, fires, fumes and a multitude of other risks.  This project should not be attempted without a thorough understanding of electricity, adult supervision and adequate training.  Misuse, or careless use, of tools or projects may result in serious injury and/or death.  Use of this content is at your own risk.
<p>Sorry my keyboard is bad. 8AWG is 8,4mm. Can I use 10 or 6 mm instead? Like 10mm, with less turns around the transformator if it gets too tight?</p>
I used 8awg with 15turns and it works great!
Finally got around to building this very suprised with its output.
thanks i wanna try it too. here they only seem to have 6 and 10 mm2 cables, it seems like 8awg is in between. can i se 1 of them?
<p>How much mm2 must 8 AWG cable?</p><p>Jozefko7@centrum.sk</p>
You are so awesome!!! And your videos are clear and professional. I will follow you to see your recent videos. I'm planning of repeating some of your projects myself.
Thank you very much!
But why would you need 50' of cable ? I only see at most like 5feet of cable being used in secondary winding??
can I wind my mots with single strand 8awg non insulated copper wire?
<p>A little confused about the direction of the secondary windings. Do the windings have to be in one direction, or can they be wound down and then back up over the previous layer? I've seen people do this without any kind of order in the windings, and I'm a little confused about how the flux actually moves the electrons.</p><p>Thanks</p>
<p>would be nice if the builder showed a little science. </p><p>Transformer primary voltage and secondary voltage based on primary turns to secondary turns. Also note by dropping voltage you increase current, SO size leads based on current at output. Look up basic electrical formulas and transformer rules. I made one with a foot pedal to start and stop welder, also added fuse to primary to protect me and the house. I worked at a welding manufacturer in Midwest. </p>
<p>I have been saving bottle caps<br></p>
Great Videos ! I'm going to build my own. One last thing : With two MOTs, how to calculate the width, the lenght and the turns to obtain a 30V and 0 120 Amps welder? you say 8 gauge with 18 turns, but if i have a different first coil, would it be the same? Best regards from France
Sir how much is the output current from this transformer ?
Grant have you posted part 2 ? <br>
Have you posted part two? and this runs on 240 volts??? nice build <br>
hay grant already made your spot welder and i love it! <br>when part 2 comes out i will make this but i am getting all of the stuff now <br>i have 2 wire choices picked out witch one (if any) do your think will be best? <br> <br>http://www.amazon.com/Cadence-4G150MP-B-50-Amplifier-Guaranteed/dp/B00BIU49VW/ref=sr_1_17?ie=UTF8&amp;qid=1365698408&amp;sr=8-17&amp;keywords=50+ft+8+gauge+wire <br> <br>http://www.amazon.com/gp/product/B00785ULO0/ref=s9_simh_gw_p422_d0_i1?pf_rd_m=ATVPDKIKX0DER&amp;pf_rd_s=center-2&amp;pf_rd_r=0RT7QW2870WFSFN463EY&amp;pf_rd_t=101&amp;pf_rd_p=1389517282&amp;pf_rd_i=507846 <br> <br>thanks hope you can answer my question
I am from Germany and I will build this ARC WELDER too. <br>is this the right cabel <br> <br>http://www.ebay.de/itm/Audiotechnik-Dietz-10-mm-mm2-QMM-Powerkabel-73-Meter-auf-Rolle-/330903831891?pt=Kabel_Stecker&amp;hash=item4d0b67c553
are you going to make a video of the dual MOT stack i saw in your video?
Thanks for asking. I wasn't planning on it. It was just unballasted on 240 volts and I'm guessing it was pulling around 20-30 amps, but not enough to pop the breaker .. even after running for 10+ seconds at a time.
You should make a video. I made I dual stack with a half-resonant circuit (2 microwave capacitors in series) and it gave me arcs about a foot long!!!
Grant, great work! I have built your spot welder and have been very impressed. <br> I have two questions with this one. 1 how small can you take this and can you use this on other metals? You are an impressive tinkerer.
Amazing Grant! I am eager for the second part!!!! :-)
Great! I'll have it up in about 2 weeks :D

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Bio: Random Weekend Projects
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