Difference between revisions of "APRIL Arm"

Revision as of 18:26, 30 October 2012

This page presents the robotic arm that the APRIL lab designed and built in-house for scholastic and research uses.

What is the APRIL arm?

The APRIL lab desired a high-quality, high-reliability, and cost-effective robot manipulator for use on robots, in the classroom (as teaching tool), and on the workbench for research tasks. Although there are a number of low-to-high quality arm in the marketplace, none fit our desired constraints. We wanted control over the quality and size of each servo, arm segment lengths (thus torque and reach), and overall cost. Thus, the current arm consists of six off-the-shelf servos, 3D printed arm segments, a wooden base, and a simple computer interface via USB.

Who could benefit from an APRIL arm?

Educators could use these high-quality robot manipulators as tools for teaching concepts such as: physics, kinematics, robotics, computer vision, and control systems. Students of robotics will certainly learn concepts with simple robots, like this arm, before moving on to more complicated robots. However, one great use of these arms is to invigorate non-robotics students with a passion and desire to learn and interact with their experiments and motivate them to pursue STEM careers.

Researchers do not particularly need the pretty consumer-grade (and expensive) robot arms being sold today. Experiments need to be run and the results do not (generally) depend the finishing material of the robot arm. Thus, this simple arm (servos and connecting plastic) allows researchers to configure their arm that meets the needs in a cost-effective manner. This is particularly important when multiple uses of the arm are required, each with differing requirements; rather than having multiple arms the cost-effective arm segments can be interchanged with little effort.

Do-it-yourself and Hackerspaces often cannot afford expensive robot arms and have multiple projects/uses for these arms. At a hackerspace, for example, multiple projects may all compete for usage of the robot arm and the APRIL arm offers multiple benefits in this regard. First, the arm is not so expensive to preclude the idea of having multiple arms if demand is high-enough (other competing arms cost up in the $10,000 range). Secondly, the arms are configurable and thus, some segments (bigger, and more expensive, servos) may be shared between projects. And lastly, the arm segment design files given here can be modified to meet the exact needs of the project (we encourage it).

How do I get/make and APRIL arm?

There are three stages to make an APRIL arm: order parts, print plastic arm segments, and assemble arms. These instructions are tailored to the configuration shown in the figure above containing a 6 DOF arm with a total reach of XX cm. See Advanced Configuration section below for ideas on how to modify this configuration to meet your needs.

Ordering parts

The APRIL arm uses the Dynamixel line of servos from Robotis. You can choose either the TTL or RS-485 variants for communications, as long as all servos are the same.

Printing plastic arm segment

Assembling arms

How do I use the APRIL arm?

Advanced Configuration

Additional contact