00:00:10microwave oven transformer as an
00:00:12electrical metal melter in this video
00:00:14you’ll learn step by step how it was
00:00:15made and what I’m using it for now
00:00:19[Music]
00:00:33in a previous project I found an old
00:00:35microwave in a dumpster and hacked it
00:00:37open to see what components I could
00:00:38salvage this power transformer was one
00:00:40of my favorites and got used in many
00:00:42other projects like high voltage
00:00:44electrical arcs making a homemade stick
00:00:47welder and melting metal in its current
00:00:50condition the transformer produces a
00:00:51deadly high voltage that’s enough to
00:00:53kill a person on contact but it won’t
00:00:55melt metal to do that we have to modify
00:00:57the transformer by rewinding the coils
00:00:59looking at the sides of this transformer
00:01:01you can see that these shallow welds are
00:01:03the only thing holding this together I’m
00:01:05gonna use my bench vise to secure this
00:01:07in place with one end of the welded
00:01:09sides facing up and try using a hacksaw
00:01:11to cut it open this is a fairly weak
00:01:13weld and a hacksaw will work but a quick
00:01:15buzz with an angle grinder works a lot
00:01:17better now that that’s ground off a
00:01:19hammer and chisel can be used to crack
00:01:21the gap and pry the pieces apart the
00:01:23rest can be removed by hand with the
00:01:25bottom off I’ve got access to the three
00:01:27coils of wire wrapped around the core
00:01:28the top coil is the primary winding and
00:01:31I want to take very good care of that so
00:01:33I’ve wrapped a cloth over my chisel to
00:01:34protect it as I pry up on the winding
00:01:36it’s in there pretty snug but frying it
00:01:38slowly and gently from both sides gets
00:01:40it to the point where I can put the
00:01:42chisels down and pull it off by hand
00:01:43these metal shunts can get knocked out
00:01:45now and amazingly this is the only form
00:01:48of current-limiting this transformer has
00:01:49the middle coil is junk and it all comes
00:01:52out then to get the secondary coil off
00:01:54I’m setting it with the coil resting on
00:01:55the jaws of my vise and then hitting the
00:01:57middle of the core with a rubber hammer
00:01:59until the winding is free this got
00:02:01pretty beat up but that’s okay because
00:02:03luckily I don’t need it a chisel works
00:02:05great for scraping off any excess paper
00:02:07and glue stuck on the sides and now
00:02:09we’ve got ourselves a naked transformer
00:02:11core you’re looking at the E and HI
00:02:13sections of the core and at this point
00:02:15we’re ready to reinstall our primary
00:02:17coil this coil has about a hundred turns
00:02:19of insulated copper wire and needs to be
00:02:21replaced gently to avoid damaging it or
00:02:23scraping the wires that’s why I’m using
00:02:25a rubber hammer so I can still get it in
00:02:27nice and
00:02:28okay it’s looking like it’s supposed to
00:02:30so now we can add a secondary winding
00:02:31made from this thick 2 gauge copper
00:02:33cable I was lucky and got this from a
00:02:35scrap pile my brother had at work
00:02:37looking inside you can see it’s made of
00:02:39stranded copper wire insulated by a
00:02:41thick rubber coating my brother got me a
00:02:43heavy-duty copper lug and crimped it in
00:02:45place on the end of the cable next he
00:02:47added a little shrink wrap to protect
00:02:49the connection and hit it with a heat
00:02:50gun to shrink it down and finish it off
00:02:52alright so with the cable bent in half I
00:02:55can move it up next to the transformer
00:02:56and tuck it down into the gaps the wire
00:02:59is so thick it’s a pretty tight fit and
00:03:01probably couldn’t be any bigger I’m
00:03:03pulling one end of the cable back around
00:03:04the transformer and I decided to switch
00:03:06the positions of these two so that it
00:03:08forms more of an ascending coil now I
00:03:10compress the other side into place and
00:03:12the secondary coil is wrapped as easy as
00:03:15that
00:03:15the last step is to put this back
00:03:17together I don’t have anything to reweld
00:03:19the scenes I broke apart so I’m gonna
00:03:21try using this two-part epoxy glue to
00:03:23see if I can make it work both the
00:03:24components get mixed equally then I’ll
00:03:26add the glue to all the exposed surfaces
00:03:28at the top here and find a way to clamp
00:03:30this down it turns out my bench vise has
00:03:32a gap wide enough to fit the entire
00:03:34assembly and after double-checking the
00:03:36alignment on the connection I’ll cinch
00:03:38it up tight I’m adding the leftover glue
00:03:40to the gaps on the edges and everything
00:03:42is looking as expected so that could be
00:03:44left to set okay it’s 2 hours later and
00:03:46our modification is complete there’s
00:03:49actually no physical connection between
00:03:50the two coils yet this will pump out
00:03:52around 800 amps to bench test the device
00:03:55I’m carefully hooking clips to both
00:03:57leads of the primary winding and then
00:03:59adding power using my multimeter I’m
00:04:01showing just over two bolts now which is
00:04:03a lot lower than the thousand volts this
00:04:05used to throw out but instead of putting
00:04:07out one amp
00:04:08now I’m getting closer to 800 what can
00:04:10you do with that mini am
00:04:12I thought it would be fun to try melting
00:04:14some metal which you can see this does
00:04:16easily the metal melts because it’s not
00:04:18as conductive as copper wire it acts
00:04:20like a resistor and heats up from the
00:04:22electrical friction until it reaches its
00:04:24melting point or until the insulation on
00:04:26the lead wires melt and the system
00:04:28shorts out well not only was this a fun
00:04:30modification but I found a practical
00:04:32application for it in making a spot
00:04:34welder like this one the high current
00:04:36can be directed to few sheets of metal
00:04:37together at one precise location look
00:04:40for how to make that in another project
00:04:42well now you know how to build the metal
00:04:44melter if you liked this video perhaps
00:04:46you’ll like some of my others check them
00:04:48out at the king of random calm
00:04:55[Music]
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