OpenMoCo

After you've selected the motor type appropriate for your project, it's time to move to the next stage of building your first motion control rig: gear selection.  Unless you've bought a motor with an attached gearbox (and even if you have, in some cases), it's time to figure out exactly how you intend transfer power from the motor into your final motion.  Just like the process of selecting a motor, you'll need to first examine your requirements, and how they might change over time.  In this article, we'll walk through the basic process of selecting the proper gear train, and the different factors that should affect your decision.

The basic factors to consider are: building vs. buying, complexity, gear ratio, precision, and braking requirements.

I've been out at SIGGRAPH 2010 for the past few days, and have had a lot of time to talk to a lot of great people about different technologies, open-source motion control, and to be honest, I've spent a lot of time on my feet!  I want to thank the all of the guys from xRez Studio for inviting me out and introducing me to lot of people, and introducing the OpenMoco project to a larger audience.  

The DollyShield is an adaptation of the Arduino Motor Shield v3 that provides directional PWM control of two DC motors, at up to 1A of current each.  In addition to the motor drivers, it also provides a stereo plug with dual opto-coupled outputs for direct camera control, a 2x16 LCD, five user input buttons, and four auxilliary inputs or outputs through two stereo jacks.  It is designed to provide an inexpensive and easy-to-use interface for two-axis motion control integrated with a camera.

This is a detailed article on installing OpenMoco-Slim on Mac OSX as well as installing OpenMoco TL Engine to the Arduino. I am not into code or scripting so most of this was foreign to me and I know there must be others who have the same lack of skills. This is meant to help those without those skills and in the process develop the skills needed for OpenMoco.

OK now onto the races. First step is to download and install Xcode Tools from Apple, this may seem unnecessary but it's needed by the following step. The URL to the Xcode download site is http://developer.apple.com/technologies/xcode.html.

One of the more daunting tasks for your first motion control project is to decide on which kind of motor you need.  The right choice in motor can save you money and effort in the long run, not to mention increase your chances of getting the shots you're looking for.  Before selecting your motor, you need to first examine what your requirements are, and how they might change over time.  In this article we'll walk you through the process of selecting a motor for a motion control rig and the different factors that should play into the decision.

The basic principles you'll need to consider in motor selection, outside of cost, are: timeframe (how long your shoots will run for), power requirements, and repeatability.

Introduction

While we spend a lot of our time focusing on stepper motors, we'd rather not leave out brushed DC motors!  It's hard to beat them for their simplicity and low cost.  When it comes to drivers for DC motors, there are a lot of options - from cheap $15 PWM drivers that can be found on eBay, to professional units that can cost up to several thousand dollars.  I've been using the Pololu JRK 21v3 driver with great success.  It offers rarely found in drivers several times its cost.  At approximately $50 USD it might seem a little pricey until you explore the options it gives you. In this article, we'll cover how to make an easy-to-use carrier board for the JRK 21v3 that will let you hook it right up into an OpenMoco system, and especially the dedicated hand-held engine model, while still retaining all of the features and flexibility of the driver.

After several months of experimentation and hard work, we are proud to announce the release of version 0.82 of the OpenMoco TimeLapse Engine. Of course, the engine still runs on the inexpensive and easy-to-buy Arduino platform, but we've expanded all of the existing capabilities and added new features to the engine that set it apart from any other open-source moco sketch you'll find, while making it more stable and useful for the timelapse experimenter.

All tests on Vimeo in HD: http://vimeo.com/9626538

We're working hard behind the scenes to get some tangible results from the openmoco engine and get you all some looks at hardware solutions. Finally pulled all the pieces together on our first dolly concept and found the results to be very encouraging (to say the least). Here's a sample video on youtube and the source file for close inspection.  I'm running the system using the windows pearl slim interface. From what I'm seeing the youtube compression is causing a little studdering but check out the source file to inspect the super smooth operation): Enjoy and look forward to more info as we continue to move forward! Not cool enough for you? Okay, okay how about verticle moves...