Whiteboard Plotter

A very long time ago, I found a Rotring NC-scriber without the controller. I totally forgot what I wanted to do with it, but last week I found it again and I want to make a whiteboard plotter out of it.

My personal handwriting on the whiteboard is not the most elegant. Some tekst stay on the whiteboard a whole semester or sometimes even longer. (some don't even dry-erase anymore) So for these texts it is worth the effort to write them nicely with a machine. It will be a lot less messy on my whiteboard. I might even pre-write some text before every new subject.

The Rotring NC_scriber is designed to write the lettering in technical drawings in the time that thew where still drawn by hand.

Materials:

• Rotring NC-scriber (or any other drawing table pen plotter)
• Arduino Uno
• Motor shield
• Some jumper cables
• Power adapter for the Arduino
• Whiteboard markers
• (optional Acrylic)
• Rubber bands / tape

Tools:

• Screwdrivers
• Whiteboard
• (optional Lasercutter)
• Computer to program the Arduino

The first step is to open it up and see what we have to work with.

I want to use the keyboard eventually but almost all the pins of my Arduino Uno are already taken by the motor shield, so for now I won't use the keyboard.

I am lucky that the steppers are 5V, so they might run directly from the motor shield without the need for an extra power adapter.

I tried all possible wiring options and the motors didn't ran smooth and the shield still ran very hot. Then I found out that the cheap motor shield I used had a soldering point that shorted with the shielding of the USB port on the Arduino Uno. A piece of electrical tape solved all my problems and the right pin setting was easily found.

I tried to find wires in the right colors and marked them X and Y motor so I wouldn't mess them up.

I downloaded the motor shield Library from Adafruit and installed it in the Arduino folder.

First I tried to draw a square with an Adafruit sketch and tried the different settings.

Now it was time to design all the letters. I made a different sub-routine for every letter. I draw them all with straight lines. (because curves are hard and I like the retro 8-bit design of the square lettering)

I drew the letters on a 5 x 3 or 5 x 5 grid. (in my head)

If you want to write a tekst, you simply call the sub-routines in the void setup() like this:

To write WELCOME, you put this in the void setup(){ w(); e(); l(); c(); o(); m(); e(); }

You can simply use some tape to add the marker to the writing head, but I have a lasercutter, so I will use it :)

I designed a simple holder that I can bolt to the head and attach the pen with a rubber band.

Until now I didn't damage anything on the original NC-scriber so it felt a bit wrong to drill holes in it to screw the arduino on. A rubber band did the trick. Later on when I add the keyboard back on, I might 3d-print or lasercut a nice attachment for the Arduino.

The pen lifting mechanism on the NC-scriber is made to write on a horizontal surface and doesn't work on the whiteboard. At first I solved this by simply pushing on the pen when it needed to write and let go when it needs to lift. There are pauses in the code to give you time for this. Because the pen is moving when you need to hold it, this didn't give good results.

So now I do it the other way around; You tilt the hole scriber a little when you don't need to write. This works great, except with the letter J. All other letters start writing in the left top corner. The letter J starts with NOT writing in the left top corner, so I did mess it up several times.

It is still a bit hard to write the sketch in the sub-routine letters, but that will be solved when the V2 motor shield arrives and I can add the keyboard again.

My whiteboard definitely looks neater, so let the classes begin!

(video is in Dutch)