Scotchbrite wheels are great for SS when all else fails and can give quite an attractive finish. Other metal and I have found them to be a little harsh. I suppose it depends on what you want/need.
This is my polisher. If it looks very neglected that's because it is. I've left it outside for the last two years in the elements. Plugged it in today and off it went, good as the day I made it about 15yrs ago......don't time fly....

I knocked it up as a quick job to polish bike parts, but over the years it just remained as you see it now. It's done an awful lot of work over the years...
The belt is tensioned by the weight of the motor which swivels on a pin. This pin slides from side to side to align the belt when you change speeds. Two speeds, 3,000 and 3,400 rpm. 3,400 is fine for 6" wheels and 3,000 for 8".
The power of the motor is unknown cos it don't say. I guess 1/2 Hp. It's 4.4A if anyone knows how that relates or has an idea.
I was always told you needed a big motor for polishing, at least 1Hp, but my experience is you don't need this much up to 8". If you are finding the motor is slowing down then you are applying too much pressure which can lead to streaking which is a real pain to get rid of once you have done it.
Far more important is high speed and a light pressure with rapid movements. ie don't stay in one spot.....ever..!!
There are tables for mop diameters and speed requirements. I find 3,500 is fine for 6" 4,000 would be better , but 8" really needs a bit less 2,500 - 3,000.
Then we come into mop types and polishes......

