Check out induction heaters, induction forges or induction metal melters. No point reinventing the wheel with a lot of moving parts.
Photo's of an induction melter used by dental labs and jewelers from the 50's and 60's it was combined with the centrifugal casting machine. it was imported to the Us for the dental trade.
The new versions have become more efficient

mini cast unit made in Italy

Looking at the innards

Looking thru the current carrying straps and cooling tubes at the coils

High freq generating tube and other parts

Heating and crucible unit, along with the water cooling tubing. as the unit was made to rest and make multiple casts as fast as possible.

A device on the back of the unit some type of breaker

Closer look at the induction coil
a video
And just for fun a smoking red hot ice cube
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There are a ton of home made units on U tube also
Google induction forges and you will get all the info you will want or need.
The final work they are expensive to buy. I have a friend that owns a off center induction unit and when she bought it it was over 5 grand.