RE: Spindle Speed control, was Re: Got the mechanical bits done tonight

Hi Jerry,

I can't remember exactly, but wasn't there a thread a while back on
using PWM to control the spindle speed? For threading it would have to
be quite precise, and I seem to recall encoders ON the spindle driving
the rates of the 'Z' lathe axis. I could be wrong again.

If the is nothing implemented, I'd like to propose something a little
different for a spindle speed control. setting a D/A converter, OR, a
few pulses to a DIGITAL POT. The digital pot replaces the pot in the KB
motor controller.

If I decide to do this, I'll have some 'C' code that can be adapted for
TurboCNC. What think you, Jerry and Dave (and of course any one else
that is interested in this thread)?

Alan KM6VV


Carol & Jerry Jankura wrote:

>
> Hi, Alan:
>
> At this time, I don't believe that TurboCNC does anything to set the spindle
> speed. Since it recognizes the 'S' parameter and stores the value. However,
> there's nothing in the code that actually sends information to a D/A
> convertor or does anything else with the value.
>
> Of course, with source code being readily available, it's something that can
> be added to the program without any difficulty (This exercise is a simple
> matter of software and is left to the student.:) )
>
> -- Jerry
>
> |I'm not John, but I'm about to do some "speed control" myself. And I
> |believe TurboCNC has some control. The KB motor controllers on the
> |Sherline spindle can easily be controlled by an external pot; and that
> |pot can be replaced with an an appropriate signal (an analog level from
> |a D/A driven by the controller program).
> |
> |Alan KM6VV