Re: [CAD_CAM_EDM_DRO] What is wanted in a controller,

Hi Drew,

Thanks for your thoughts! I think I see what you're talking about with
the video tape jog knob. I have a high end Sony VCR with a knob that
sounds like what you're describing. My remote probably didn't cost
$200-300, but I get what you mean. This would be different then a
"directly calibrated" jog wheel, which would be more like a manual
machine. Two different approaches.

The feedrate knob is one I (hobbyist) hadn't considered until these
threads. I can see how it would be useful. That sounds more like an
absolute shaft encoder. Or perhaps a pot and A/D.

Spindle on/off, coolant on/off etc. buttons would be easily added to a
pendent. After a few more devices, it makes sense to do it with a PIC,
to minimize the "wires" between the pendent and the control panel, and
read the various "analog" input devices.

Alan KM6VV


Drew Rogge wrote:

>
> Hi Alan,
>
> I guess the things I miss most are having knobs for slewing the
> axes, overriding feedrate and if I had a spindle with controlable
> speed then I would want a knob for overriding that. It would be
> nice if the override knobs had a detent at the position where
> the feed/speed was at the programed rate. It would real nice if
> the slew knob automaticly returned back to 0 when released.
>
> I'm really fond of the type of knob that's used on the high end
> video tape decks. They're a two function knob where in on mode I
> think they're just a rotary encoder and spining the knob just causes
> the tape to move forward or backwards. If you press and release on
> the knob it switches into a mode which has a detent at the mid point,
> becomes spring loaded to return to the midpoint and when you twist
> the knob in direction the tape starts slewing at a speed relative
> to how far you've twisted the knob. Also in this mode if you twist
> the knob further that say 1/4 turn, it seems like the slew rate gets
> multiplied by a value of 2 or 3. Pressing and releasing the knob
> switches it back to jog mode. The only problem with these knobs is
> the cost. $200 or $300 apiece I've been told. Oh, well.
>
> I haven't thought too much about what kind of buttons or switches
> I would need. A rotary switch to select which axis was connected
> to the jog and/or slew knob(s) would be needed. I think it would
> be handy to have jog buttons which would move an axis (or the selected
> axis) by a selectable increment.
>
> Buttons for turning the spindle and other various functions on
> and odd may be handy.
>
> It's real handy to be able to pause a program in mid cut, jog
> the axes around and then resume the program. This comes in handy
> for picking up a surface or adjusting the depth of cut.
>
> I'm sure there's a whole bunch of other stuff I'm missing. But thanks
> for listening.
>
> Drew
>
> Alan Marconett KM6VV wrote:
> >
> > Hi Drew,
> >
> > Yes, that'd be a good place to start! A good pendant design, or a
> > "control panel", could get us going in the correct direction. I'd be
> > curious to hear what you'd like to see. I made one real simple, a panel
> > shaft encoder, and two PB's. the push buttons allow one to "rotate"
> > through the axis choices, and the jog sizes. Fits in a little aluminum
> > die cast case, and plugs into the joystick connector. The interface
> > uses the four "switch" pin lines. No R/C time constant joystick. I DO
> > have a good analog joystick that I'd interfaced via a pair of A/D
> > channels (for the robot I posted some time ago), might give that a try.
> > the A/D I did for something else; it's 4 channel (and a stepper!). The
> > A/D is a serial part, read by bit banger (slow) code through the
> > parallel port. Guess one could also add a bit banger D/A port as well!
> >
> > I think Jon has some A/D or D/A on his interface?
> >
> > Alan KM6VV