This is a quite clever redstone machine which lets you build an electric furnace. The electric furnace is much better than an ordinary furnace since it doesn’t require any fuel (e.g. coal) to run. However, the downside is that it is slower than an ordinary furnace and doesn’t have the same mobility since it requires the redstone structure to be somewhere close to function properly.
How does it work?
Turn on the machine by pushing the lever downwards. This is required in order to be able to build the electric furnace.
To build the electric furnace you will need one normal furnace block, one rail track and one minecart with hopper. Begin by first placing down the rail track. Then place the furnace on top of it. And then lastly place the minecart with hopper on the rail track.
You can now open the furnace UI (user interface) and start smelting your items. The process is slightly slower than a normal furnace, but the advantage is that you don’t need any fuel.