Quote Originally Posted by 3DTOPO View Post
A 15KW or more powerful one? I would like to see that!

I've only see toy sized ones "easily" made. The amount of hardware alone needed to build a 15KW induction furnace is anything but trivial.
15kw really isn't that hard. The hard part is powering it. You need around 80 amps, assuming a normal inefficiency (likely that the efficiency would be much higher than 80%, haven't done the math) of 230v single phase power. A single sub panel in a well equipped home can handle that and the lights in the shop without significant issue.

Then, you need at least 1 awg power cable to handle the current draw, which isn't an issue since you should have the sub panel within a couple yards of the device. I would just be safe and buy 0 gauge, because it is more commonly available and not really any more expensive. So that gives you a pretty good safety factor on the power supply.

After that, you need a variable frequency drive of some manner. This can be purchased outright if you have the coin, or built if you have the knowledge. The mechanics of which I am not entirely clear on, though I do understand how to do it at a much lower current/voltage. I think it involves suitable capacitance. I could research further if I intended to build one, but if I recall my electrical courses correctly you would ideally do so in parallel.

From there, you have your work coil. You would use some solid copper and plenty of applied muscle to wind it.

Stick a nice crucible in the middle, and there you go. If you want to get really fancy, you can liquid cool the work coil.

It isn't really a matter of it being difficult, the problem is one of scale. 15kw is hard to obtain for a home user, but certainly possible.

I suspect I could build one with reasonable safety devices, liquid cooled coil, appropriate power (including professional installation of the sub panel) and have it running for maybe 3k USD.


BUUUTTT that's all theory. I have had enough practice on projects of that scope to know that there are always unseen obstacles that slow things down. That's the part where many home users cut corners, do something dangerous, and kill themselves.