Re: [CAD_CAM_EDM_DRO] stepper vs servo

In a message dated 07-Aug-01 19:17:45 Central Daylight Time,
cadcamcenter@... writes:

> Hope this is incorrect, otherwise the servo may be not that much more
> better at avoiding spoilt parts than steppers.
>
>

The X- and Y- steppers are independent, so, if the controller sends
move-commands (some number of steps) to both nearly-simultaneously, and one
stalls against some mechanical obstacle, the other "never knows this
happened", so, you have a serious snafu! In the servo system, the "computer"
knows what BOTH are doing (assuming you have shaft-encoders on both X- and Y-
servos), so, if one gets hung-up, the computer just waits, and/or shuts-down.
If you are modifying an extant lathe to attach lead-screw drives yourself,
you will have vastly less grief and expense if you "start out" with steppers,
at least until you teach yourself what it's all about!

I do not use nor "read" G-code. I only know kinda what it is, and what a
"block number" is, and that a "G number" tells the machine something like,
"Hey, this will be a linear move to X and Y..." or whatever. X,Y, and
Feedrate. I do all MY programming in GWBASIC, using a self-written ASM-86
patch to "step" the two motors and turn the spindle-motor on/off via the
printer-port. Simple stuff. FOR-NEXT loops.


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