Here's a front view of the whole bandsaw showing the location of the the two drive motors.
The lower motor was there when I got the saw about 45 years ago. It runs the bandsaw for the "wood" speed.
The upper motor is a 1/4 HP, 100 rpm gear reduction motor that I salvaged from a large old copy machine.
Here's the backside of the same saw and you can see the output shaft of the gear reduction motor under the tin shield that I made to protect it from metal shavings.
Also, if you look closely, you can see the the "other" belt hanging on the front lip of the shield.
So the belt that's NOT in use is always easy to spot and to find when I need to change speeds.
Here's a close-up of the longer, "Wood Speed" belt in place:
And here's the shorter, "Metal Speed" belt attached to the gear reduction motor. This motor is mounted on a hinged board to make belt changing easier.
There's also a threaded rod that I use to adjust tension.
There is only a single toggle switch used to run both motors.
You can see the female power receptacle. That is the power coming FROM the switch.
I put a short power cord with plug on each motor. That way, I can plug whichever motor I want into to switched power source, always using the same on/off switch.
That's all there is to it. I have a wide range of both wood and metal cutting blades. And I keep the metal cutting blades completely separate from the ones I use for wood.
Just to keep the saw clean for wood cutting, I don't use coolant when cutting metal.