I had a home built machine at the start, grit, plumbing bells for rough cuts and pvc cups for polishing and really messy. I bought the HP machine as the web site showed the same motors as my home built one. When it arrived the motors, were different very disappointed, the gear heads are set at 105 rpm which match my old motors but won't mount to the HP machine , I looked at the high speed machine but went with this one to match my old motors, I have since rebuilt the hinges abandoned the bungy cords, I use four sets of springs with different tensions I can make the rock spin any direction I want. I use diamond sintered segment cups for 80,220,400 rough, and diamond impegnated polymer cup for polishing 400 to 8000. Although I don't use the 8k very often.
Buying the cups is expensive, but I'm pleased with the results I get.
Jhon is correct, now you'll need bigger rocks and a bigger saw!!!!