Rotary Table, Welding, And The Propeller
idbruce
Posts: 6,197
Hello Everyone
I want to create a rotary table for making circular welds, however I am uncertain of the requirements. Will the stepper motor and supporting electronics need to be electrically isolated from the welder ground? In other words, can I directly rotate my work piece with the stepper motor using a steel coupling, and can I mount my project box, containing a Propeller, to the rotary table? To elaborate a bit further, the project box and stepper would be mounted to a steel table, the stepper would rotate the work piece with a steel coupling, and the welder ground would be attached to the work piece.
I want to create a rotary table for making circular welds, however I am uncertain of the requirements. Will the stepper motor and supporting electronics need to be electrically isolated from the welder ground? In other words, can I directly rotate my work piece with the stepper motor using a steel coupling, and can I mount my project box, containing a Propeller, to the rotary table? To elaborate a bit further, the project box and stepper would be mounted to a steel table, the stepper would rotate the work piece with a steel coupling, and the welder ground would be attached to the work piece.
Comments
Instead of a steel coupling you could use the same methods used on old record players - just use a rubber belt for insulation.
I think shielding the electronics might also be sensible. A simple test would be to run one of your existing Propeller boards next to the welder and weld something.
Enjoy!
Mike
That means you could use a single point earth approach, where you take care to ensure welder currents go nowhere near signals.
Maybe, but that is a big first step, so first I'd physically separate the two and isolate things, then when you have that working, start reducing the separation and isolation, until it starts to fail....
Possible isolation parts would be H11L1, logic optocoupler, or the new Si8751/Si8752 isolated gate drivers can likely achieve stepper speeds,
and mean you have only (overrated) mosfets and the gate signals 'at the coal-face'. Current drive those down the isolation cables.
Motor power is done quite separate from Prop Power.