On Fri, Feb 22, 2008 at 10:22:46AM +0000, Ian W. Wright wrote: > Hi, > > I've been looking at the 'nist-lathe' config files and trawling the web > for more info on this but pretty much drawn a blank as far as the info I > want is concerned. So, can anyone please tell me: > > 1. What electronics were involved in hooking up the spindle motor to the > PWM output of the parallel port.
It uses the KBIC isolator board that takes 0-5v isolated analog in. It's convenient for other reasons if EMC can control the spindle speed, but be aware this is not necessary for threading. EMC just reads the spindle position and follows it with the moving axis/axes. > 2. What kind of encoder is needed - does it need to be a full quadrature > encoder or a simple 'disk-with-one-slit' and a photocell? An encoder with index pulse. If your spindle does not reverse, you can get by with less than a full encoder: see the "counter" section in the encoder man page. Still, many pulses per rev are required. > Consequently, the pitch, even if aimed for a > particular number, was always approximate and 40 TPI might well come out > at 41 2/3 TPI. For proper restoration work, it is essential that any new > screws match the originals as closely as possible If you measure your screw pitch as 41.737 TPI, you can cut that pitch just as easily as any other. Chris ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
