re;Re: Threading

Ballendo,

Ahh, isn't this Thompson's rule or something? Perceived ease of
task varies in inverse proportion to nearness to it.

I'm working on a PC parallel port threading algorithm right now for
my next software rev, and it's not a particularly simple problem.
Three conditions have to be satisfied:

- Slewing of axis in appropriate ratio to spindle speed, at any speed.
- Mark registration for multiple passes to align correctly.
- "Look ahead" to stay within acceleration limits for the axis.

Tough nut to crack, especially if there's no index pulse on the
spindle encoder, or if the encoder can have any arbitrary number of
slots from one up! Think I've got it figured out though...

Dave Kowalczyk
Ames IA

--- In CAD_CAM_EDM_DRO@egroups.com, ballendo@y... wrote:
>
> P.S. It would be fairly simple to just use a "divide by N" circuit
> (or PIC program) to do lathe threading WITHOUT the computer. (every
N
> encoder pulses, spit a stepper pulse). Include the encoder "index"
> pulse(if direct driven) or a hall effect "index" input for multiple
> start threads. Increasing/decreasing lead would be tougher, but
still
> PIC-able.