Message #23413 Re:DeskNC - CNC Pro 3x as fast as EMC???

Larry,
A PIC would only save a person money if they had the
programmer and experence. A man wants to sail a boat
across the ocean. He know how to sail, he just needs a
boat! You suggest he flies a plane instead! He only
needs to learn how to fly! Oh yea! he needs a plane, right?
In your defence PICs would work good. The controller
that runs the CNCJr has three of them. The problem with
the controller and the software is it is propritary. The CNCJr
is stuck with one software type. There are more powerful
simplier solutions than to use a PIC. Let the software do
the work! My point is! CNC is hard enough to learn without
more throwing curves at a beginner.


John

--- In CAD_CAM_EDM_DRO@y..., "Larry Edington" <ledington@c...> wrote:
> > Larry,
> > What added cost is there to program the PIC? It
> > is obvious you have mastered PICs! A person going
> >with your suggestion now has to add more to his
> >plate.
>
> But you were advocating just a few messages ago to do it yourself
to learn
> something!
>
> If you build your own programmer, very little additional cost other
than
> time. Most 'non programmer' types can program in Basic rather
quickly. Basic
> PIC compilers are cheap. If you want to learn assembly language
> programming, then it can all be practically free. You can also pick
up the
> Microchip or Advanced Transdata 16F877 in circuit debugger /
programmer (
> ICD ) for around $150. Or you can build that yourself too using the
plans
> from www.epemag.com
>
>
> > I say build a simple controller capable of 6amps at
> > 60 volts per phase. The circuit has been around for 30 years!
> > It uses cheap chips and almost all Radio Shack parts. >Where can
> > you find such a diagram, you ask? Well look I have a >website TOO!
>
> The problems I see with your circuit is: (1) It's a Unipolar drive
which
> costs a lot of torque the motor could otherwise produce. (2). It
uses
> discrete logic ( flip flops and xor gates ) all of which are built
into the
> L297 so why build it out of discrete logic? (3). It is an LR drive
which
> means lots of power wasted as heat. (4). It has no current feedback
so you
> can't drive the motors at optimum settings as a chopper drive can.
>
> By the time a novice electronics technician could build your
circuit, they
> could put an L297 / L298 board together and have a better performing
> circuit.
>
> later,
> Larry E.