[Tutor] Pen plotter data format

[Phil]

On 2/4/23 10:09, Dennis Lee Bieber wrote:

>
> 	Those are going to make things tricky -- different rotation speeds will
> skew any plots, and you have no means of determining the location of the
> pen.

The Lego motors have built-in position encoders. The main cause of 
inaccuracy seems to gear backlash and a bit of slop in the motor. I only 
have the x axis working at the moment but it seems to work well enough.

Following your advice, I had a look at an Arduino GRB library and 
"Universal Gcode Sender".  A very useful combination if I were using an 
Arduino board.


> 	Small servo motor and some sort of parallelogram arm (keeping the pen
> vertical as the arm moves up and down).

I'm thing a cam on a Lego motor might do the job.


-- 
Regards,
Phil