motor shot

Drawing machine stepper motors

Things are about to get a bit nerdy.

I’ve been meaning to write a technical note on the motors that I use for the Dimensions of Line drawing machine for a while now. I’m currently using a pair of these EvoDrive ST-23 Stepper Servo motors along with an integrated Evoduino micro-controller. This allows me to write code to control the motors with arduino platform. I’ve used a variety of sketches (the arduino lingo for the programs that run on the micro-controller) for both the moments of force works and the programmed material variation works like those in the IOU in Material Thought exhibition.

I decided on the EvoDrive motors mostly because as a contoller/motor unit they run quieter than any other stepper motor/controller combination I could find. This was an aesthetic decision. I wanted the machine to be quiet enough so that people would focus on the way that I was interfacing with it rather than be overwhelmed by the sounds of its mechanical functioning. While there is some level of sound coming from the motors a lot of the sound that comes from the machine is from the bearings running on their tracks.

Interestingly a lack of noise also indicates that the motor is running more efficiently (noise, after all, requires energy to to be made) so my aesthetic criteria turned out to be a reasonable proxy for choosing a high performing motor in other areas, (these motors use less power for the same torque than other motor/controller combinations).

A few other things that I think is great about these motors. They come from an innovative Australian company and their customer service has been amazing. Matt from EVA Robotics not only contacted me personally when I first purchased one of his motors he has also given me invaluable advice in helping me to overcome some of the technical difficulties that I’ve had with the programming of the machine.

The motors themselves have never missed a beat. Totally reliable after almost two years of use. This might be starting to sound like a brazen plug for EVA Robotics but if a company makes a product that is this good and backs it up with great service then I reckon they deserve a plug.

If you’re interested in having a look at the code that I’m using to run the machine get in touch via the contact page and I’ll happily pass it on.