Tag Archives: steppers

DIY plotter, the video

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I have finally managed to edit the video of my DIY plotter, I hope you enjoy it!

As you can see from the video, I have put the electronic inside the scanner, and I have improved the pen holder. I have also found an acceptable solution for cables of steppers, and added a reset/halt button.

DIY plotter, Arduino and grblShield inside the scanner body

DIY plotter closed. The red pin is the reset/halt button.

Now the plotter is a self-contained device, with just USB and power plugs (Arduino is power by the USB, the grblShield by a 12V 3.3A power source got from an old monitor).

Links and downloads

To sum up the experience of building this plotter I want to list all the resources that have been useful/necessary for me to complete it. I will follow the direction that goes from having the idea of plotting my “John Moses Olano” picture to actually having it plotted on a piece of paper.

  • A picture of John Moses Olano (yes, it’s me with a John Fitzgerald Kennedy/Barack Hussein Obama/Franklin Delano Roosevelt/George Walker Bush -style name).

    John Moses Olano

  • Inkscape, used for vectorial convertion.
  • Gcodetools, (inkscape plugin) used to produce g-code out of paths, and hatching inside the areas of such paths.
  • JMO in svg format and in g-code format.
  • A script to stream the g-code file, written in processing.
  • An Arduino UNO board (Arduino is the key enabling technology in the whole flow!), loaded with GRBL firmware (which shows off the full power of Arduino).
  • A grblShield plugged on the Arduino (I love how much work it saved to me).
  • From this point on you can’t download or buy an exact replica of what I have used to build my plotter, it is just imagination (and budget, which was low in my case).
  • The X axis: an old parallel port scanner, whose scanning head supports…
  • The Y axis: the core of an old Xerox printer, whose cartridge unit supports…
  • The Z axis: the head movement unit of a floppy disk drive (though I have explored other possibilities), which supports the pen.

All this stuff to draw something on a piece of paper. Something that I could have done with a printer in 20 seconds!

The fun, the satisfaction, the true experience is not in reaching the goal, it is in the travel you do to reach the goal. And this has been a very nice travel, during which I have learnt many new things and met many nice persons.

Converting an unipolar stepper to bipolar

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While building my DIY plotter I discovered that the stepper the drives the scanner (X axis) is a unipolar five-wire type. The grblShield drives only bipolar four-wires steppers and so I faced a problem with two possible solutions:

  1. find a bipolar stepper that fits into the place of the original unipolar stepper
  2. convert the wiring of the unipolar stepper to a bipolar wiring.

The first solution is simple if you are doing a serious industrial project, it is not simple if are doing a money-less, fantasy-and-fun project. like mine.

So I tried the second solution (and if I broke the stepper the first solution was still valid). Continue reading →