Re: 4th Axis Concept (long)

Hi Tony,

Sounds great! Which PIC are you using? All .ASM, or some 'C'? Do you
do accel/decel? I've been wanting to get stepper code into a PIC!

Alan KM6VV
P.S. I've got a CNC rotary table, PIC's, etc. if you want someone to
Beta.

tony@... wrote:

>
> --- In CAD_CAM_EDM_DRO@y..., Chris L <datac@l...> wrote:
> > Sheez, if this is this basic why is no one marketing such a little
> beast? You know
> > what they get for a small powered Indexer.......
>
> Talking of small powered indexers, I have a working prototype of a
> small powered indexer, based on a PIC microcontroller and a bipolar
> drive (L297/298), intended to drive a rotary table or dividing head
> fitted with a 400 half-steps per rev stepper motor. Brief features
> list (at present):
>
> - 2-line by 16-character LCD display and 16-key membrane keypad;
> - Setup parameters stored in Non Volatile RAM - remembers the
> settings from last time it was powered on;
> - Will cater for any worm/drive ratio between 1:1 and 99:1;
> - Adjustable initial/max feedrates and jog rates, from dead slow to
> around 60 degrees/s with a 72:1 worm drive (e.g., the Sherline rotary
> table);
> - Adjustable ramp rate;
> - Software-based backlash compensation;
> - Bipolar chopper drive - usual L298 spec (2 amps/phase), with
> chopping current settable via software;
> - "Jog Mode" gives CW/CCW jog in increments of 1/100th, 1/10th, 1 and
> 10 degrees, with display of desired and actual angular position to 3
> decimal places (where the desired position cannot be achieved, actual
> position is within 1/2 step of the desired position);
> - "Division Mode" allows operator to set the number of divisions
> between 1 and 999. Table can be driven CW and CCW one division at a
> time - display shows current division number, plus actual angular
> position in range 0 - 359.999 degrees;
> - "E-Stop" key halts any move immediately, but the current/desired
> angular position is remembered - hence, position is not lost on E
> Stop.
> - "Degrees Mode" - similar to Division Mode, but the move is
> specified in degrees to 3 DP;
> - Motor connector is plug-compatible with Taig's CNC equipment (6-pin
> DIN plug);
> - Breakout connector provides for external control of CW/CCW moves
> and E-Stop, and also provides step/direction outputs if needed to
> control a higher power driver stage.
>
> I'm currently working on getting the board into production - watch
> this space.
>
> Regards,
> Tony