With an 8ft machine with typical line resistance a direct short is probably not that big a problem. You don't say what voltage your machine is but for 24v I would suggest 2 ohms step one, 1 ohm step 2 and direct short step 3.
If your rectifiers are on the tower remember that you must not short the battery.
Maybe for 12v halve those resistances and for 24v double them. Should be near enough, better on the mill and far better on the switch.
Flux