Quote Originally Posted by SWMS View Post
If you bought the machine from China I would earth it using the spike. It could be that parts of the machine are electrically isolated from each other. In which case, knowing how they connect the laser tubes, I wouldn't fancy 25 volts bouncing around the frame. :) Basically as he above said. :)
you have to consider it in more detail than that !
It depends on your current earth setup.
If my earth is from the elec provider .. and I install a spike .. there could be considerable difference in potential from one earth to the other .. this would cause a large current to flow in the earth wiring.

If I was to add a spike in the workshop, it would be best to use that earth for the whole workshop, and "lift" the incoming earth from the supply