Announcing the Arduino grblShield


I love how many of the maker geniuses who work on our site are usually up to something behind the scenes — some new project, new product, Pinky and the Brain-type schemes for taking over the world. I was talking to new contributor Riley Porter the other night about the Make: Arduino page he’s been helping us with and fun things we could do on it. He said: “Hey, I have something that might be cool.” And then he proceeded to tell me about a new Arduino Shield he and fellow DC hacker (and MAKE contributor) Alden Hart have been working on. It uses the grbl (pronounced “garble”) motion control language and the Arduino Shield formfactor to create a cheap 3-axis motion control system that can plug into Arduino boards. “Do you think you’d like to announce this on the site?” Heck yeah!

Find out more on this Make: Arduino page.

32 thoughts on “Announcing the Arduino grblShield

  1. Anonymous says:

    Really nice! I’m sure the bells and whistles will follow but for now this is a huge leg-up for the rest of us! Thanks!

    1. riley porter says:

      Exactly, Actually the image above is the prototype v2 board. We have the v3 on order now. What it does is allows for all pins not being used by grbl to be used. Of course you would need to code the usage into grbl.


      1. Scott Rocca says:

        I noticed that the board can be used for 3 axis movement. Could this be an even cheaper way of controlling a 3D printer or even a CNC machine? If so, then I am defiantly excited.

        1. riley porter says:

          This is pretty much the idea :) Out of box this is a CNC 3 axis mill controller. However, if you wanted to control a 3d printer than you would need to add support for M codes (I think this is what reprap uses) and add some controlling logic through the unused pins to say a extruder etc.

  2. Kevin Gunn says:

    Is this Open Source Hardware or proprietary? If it’s Open it’s a big win for Open Source robotics. If not, it’s still a nice bit of work and should inspire the OSHW community to create something similar.

    1. riley porter says:

      This is open source hardware. However we are still reviewing the OSHW license. We are not sure we will go with it or not yet. We will not release anything for a few more weeks. This is because we want to get everything correct before doing so. Our prototype board (seen above) works fine. Or v3 board too works now too. Our production models are very very close.

      1. Kevin Gunn says:

        Absolutely awesome! You have my respect.

  3. Anonymous says:

    I can has shield?

  4. Anonymous says:

    Way cool!

  5. Anonymous says:

    Have you really been able to run 5A per channel through those things continuously?

    1. riley porter says:

      5A is 2x the recommended max for these TI drivers. I would say “I dunno” I would really depend on the cooling, heat sinking and load. On our TinyG board (A more fully featured version of this little board) we use the same steppers.
      We got mini-heat sinks and then custom milled one for the bottom. A bit overkill? Prolly… We drove the 3 Amps from these however. Heres the image :)

      Do I recommend 5A on this board ? I would say no.. :)


      1. Anonymous says:

        I figured this was the case. The reason I asked is because both the MAKE:Arduino page and the synthetos page list these as running at “up to 2.5A per winding” (or 5A per motor) with no mention of a heatsink. You might want to change the specs as listed on those sites, or perhaps include both continuous and peak current values.

        I think this board looks like a great product, and I’ll probably be picking one up myself. Nice work!

        1. riley porter says:

          John, My mistake. I always think per axis when I say 2.5A. It IS per winding.. SO you are right. It IS rated for 5A per motor. We have not got that high. However with a fan and heat sink I bet its possible…. In other words…. Challenge Accepted… :)

 – Here is the datasheet for details. It has a heat sink section too in there.

          1. AldenHart says:

            johngineer, grblshield is essentially the motor section of TinyG, but with somewhat less copper due to shield space imitations.
            We have run TinyG boards at above their rated amperage (about 2.8 amps/winding) on TinyG with heavy heatsinks. These are Athlon heatsinks milled to fit under the board. Way overkill. We have considered an “upside down” version of grblshield to do the same thing. But really what’s needed for pushing grblshield current limits is a fan blowing through the arduino/shield gap.


  6. Jonathan Adam Williams says:

    Can you undo writing Grbl to your Arduino? It looks like you write to it using avrdude, how do you get the arduino boot loader back?

    1. AldenHart says:

      To reload the Arduino bootloader go to the “Tools” menu tab in the Arduino top menu bar and select “Burn Bootloader”. Select your programmer and it goes. You can flip back and forth between grbl and Arduino relatively easily – Alden

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Gareth Branwyn is a freelance writer and the former Editorial Director of Maker Media. He is the author or editor of over a dozen books on technology, DIY, and geek culture. He is currently a contributor to Boing Boing, Wink Books, and Wink Fun. And he has a new best-of writing collection and “lazy man’s memoir,” called Borg Like Me.

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