Re: [CAD_CAM_EDM_DRO] VEX CNC

Hmmm. In'n you want to use C, that ought to work If, however, you
prefer BASIC instead of C, you might want to know about the Picaxe
series of microcontrollers. Only takes a serial cable and 2 resistors
to program them, and they are very flexible and simple (they are
intended for the education market, and are based on PIC
microcontrollers). The IDE (aka the Programming Editor) is free and
allows for in-circuit programming, etc. There is also a native Servo
command They are manufactured by http://www.rev-ed.co.uk/picaxe/

There is also a very active and helpful forum on the Rev Ed site.

There are several distributors in the US in the $3 - $12 range depending
on the chip (8 pin to 40). They make a nice 3 servo controller board
for about $12-15 that runs off the 08M that might be just the ticket for
you to play with. Note the Vex servos are wonderful for plugging into
breadboards, but do not plug in to regular R/C type equipment. However,
the serial LCD display cable
http://www.parallax.com/Store/Accessories/CablesConverters/tabid/166/CategoryID/40/List/0/Level/a/ProductID/385/Default.aspx?SortField=ProductName%2cProductName
will adapt it to standard hobby RC equipment.

Drawing circles might be "interesting.", though straight X/Y lines would
be pretty straightforward. Do not expect incredibly high accuracy with
the servos, though.

Cheers,

Wreno

ebiz_59 wrote:

>
> My highschool science club is the proud owner of a couple VEX kits -
> erector sets with brains. We are thinking of making a CNC project
> with this VEX - more as a learning exercise than functional. We would
> probably just use a Sharpie pen on paper, or something like that. The
> motors are controlled by a servo PWM signal as we understand it, and
> we can create autonomous functions. However, that programming is done
> in C, and I can see where we could make a square, or even a slanted
> line, maybe, but I'm puzzled as to how to make, say a circle or
> something more complex than a straight line. Are we going to have
> more problems than it is worth, and learn mostly that we need to
> finish our stepper controller, and use a CAD/CAM program to do this,
> or mgiht this be an interesting project, if the mentor just knew what
> he was doing?? Thanks, Chuck
>
>
> ------------------------------------------------------------------------
>
>
> No virus found in this incoming message.
> Checked by AVG - http://www.avg.com
> Version: 8.0.169 / Virus Database: 270.6.19/1663 - Release Date: 9/9/2008 7:04 PM
>
>

[Non-text portions of this message have been removed]