I have a little Rockwell 3-phase grinder I picked up recently. It had been wired
completely wrong and today I rewired it and it runs smooth as glass. I have the
same problem with it that I have had with every bench grinder, though. The shaft
spins one way, so the wheels rotate down towards the tool rest. The nut on one
end of the shaft is RH and the nut on the other end is LH. If I put a wrench on
both shaft nuts and crank, one will loosen. The question is, how do I loosen the
other one? I can't for the life of me see why grinder manufacturers don't put a
hole you can put a pin in to lock the shaft for changing wheels. I sure don't
want to put Vise Grips on the naked threads - what is the trick I'm missing?

GWE