Hi GrayUK, Oh dear! - As Mark said – I’m in trouble now. Basically I am committed to using Mach3 and it currently does everything I want it to do. I had a problem (with laser control) some two years ago and Artsoft kindly modified their Mach3 code for me and resolved the problem I was experiencing. Could not get better service than that. At the time, AndreJ at Planet-cnc was also most helpful in discussions regarding the CNC USB controller and it’s laser on/off switching times etc. and I would have changed to their controller then had Artsoft been unable to modify their code. Unfortunately, the parallel port will not be around forever nor will PCI slots so USB or, in preference, Ethernet connection is the way forward. I do have, and operate one machine, with the Warp9 Smooth Stepper but it really does not suit my PWM system of laser control quite as well as the parallel port does. I think that rapidly changing technology perhaps places us all in a ‘Catch22’ situation. Tweakie.
Hi Robert, I am with you 100% on that - the Star GND is probably the most important single factor that is overlooked by most new constructors / builders who then run into electrical noise related issues when operating their new CNC machine. Tweakie.
Probably wouldn't hurt to mention that if you are running multiple independent power supplies, like I am with Ultimo, that the same rule applies to the hot leads as well. You should never use a jumper (series connection) for the same reason. I also recommend using shielded cable for all the interconnects to cut down on crosstalk between circuits. I can't understand why folks would spend thousands for a setup then skimp the few pennies it costs to upgrade to the shielded cables.
A star configuration is where each connection has it's own wire back to a main connection or hookup point. As opposed to a jumper or series connection where only one component is hooked up to the main and the rest jump from one to another ending at the last component hooked up.
Are you saying? Each component must have it's own independent Supply and Earth? No running in series stuff?
Would any of you advise avoiding the "Catch 22" situation by going down the USB path at the outset? It would seem the logical thing to do, after reading what you guys think. I like the idea, and it seems to make sense.
You don't "have to" run the star topology. Some systems can get away with running series connections and never have a problem. But you have a much higher chance of encountering issues with noise being induced in the series configuration, and steppers are notorious for generating noise.
