Re: Now that the intro is over...

--- In CAD_CAM_EDM_DRO@egroups.com, "Tim Goldstein" <timg@k...> wrote:

> There is a lot of EMF interference with a plasma rig and servos are

more

> sensitive to picking this interference up in my limited experience.

Plasma torch = giant spark gap generator. Needs attention to EMI
shielding and drive circuit isolation. One of the reasons I am
looking at the Gecko 320 drive is that it is self contained and could
possibly be driven with optoisolated step and direction commands with
no common ground. Years in the design of large switching power
supplies taught me respect for what interferance can do to control
electronics. (Jump in Mariss if you want!)

Not to

> say that it can't be made to work, but just another thing to think

about.

> Why do you not want to go with steppers on the plasma rig? Slightly

cheaper

> and certainly easier to set up. I have a friend that has a

Torchmate rig. He

> got the gantry kit and is using a Camtronics controller with

steppers. Seems

> to have more than enough top speed and the accuracy seems very

good. He has

> used it with an oxy-acetylene rig, but started having severe

interference

> when he tried his plasma torch.

I want to use twin motors to drive my gantry at both ends and I have
nightmares about how open loop control could put my machine in yoga
positions.

Just got off SuperCam's site and they have some interesting
software. Their kit is a little out of my price range but their
composite poly-aluminum castings (non-conductive) are innovative.