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

11. Not yet lost in translation

Got there. It's not perfect but it's a good progress.

I managed to built the gantry over which some kind of a cart can move, controlled by one axis of the CNC shield + Arduino.

Here it is in action:

Looks ok so far.

Yet I was surprised that the belt vibrates so much. Also the stepper motor is quite nosy, especially as the whole aluminum structure resonates.

Apparently the quality of piloting the stepper motor depends on the drivers I am using: I bought another set of drivers and I will check one of these days if it makes any difference.