13. X, Y and a pen

It starts to look like what it is meant to be: a 2D plotter.

I just need to add a pen, which is achieved with nice linear shafts on the vertical axis. Yet no command to lift the pen at this time: it draws a continuous line for now.

It allows to make a simple test to check how precisely it closes a rectangle or write over the same lines several times. Here it is in motion:


Precision-wise, I'm not so happy: around 2 mm while I was targeting around 0.5 mm. I still have a bit of a way.

12. X and Y

One more axis.

I left my 2D plotter away for some time. Back with the 2nd axis: Y

For this Y-axis, I use 2 stepper motors, hence 2 servos, one for Y and the other one for A, configured to duplicate Y. I added two jumpers as shown here:

Initially, both stepper motors were turning in the same direction, which considering their position on the board is wrong. I needed one of the to turn in the opposite direction: easy, it's just a matter of inverting its connection on the CNC shield. Note the wires: black, green, red, blue on the left-inside (A) and opposite on the right in-side (Y).

I also created a wood box to hold electronic parts together.

Closed, the PC sits on the top and I have an emergency stop on the left in-side that works !

And now the result in motion:

Note just for the record: few useful G-code commands

• ! = Hold
• ~ = Start cycle
• ?  = Current Position/Status
• $$ = Current Settings