Servo - August 2013

FIGURE 12A. Wheeled robot with direct drive.

tools, and many more items of applicable interest to robotics and mechatronics. I highly recommend that you go to their site to view all their products. The site has dimensional drawings, clear photographs, photos of multiple uses, applicable mounting brackets, and accessories.

FIGURE 12B. An Ackermann steering configuration.

Building a Robotic Platform

As I mentioned earlier, the R&D people sent me the robot arm base in Figure 2 to modify and use in experiments. They wanted to show the versatility of their various components and structural items, and get my feedback. I decided to modify it a bit with basic ServoCity (but also Actobotics) mechanical components,

FIGURE 12C. Chain drive configuration.

just to see how easily I could change the configuration using only these parts. Figure 11 shows a few of the changes I made. I removed the chain drive and replaced it with two servos at the end. (Easy changing of configurations during a prototyping process is important in selecting a final design.) The two wheels are driven by a set of their 12 VDC gearmotors, of which they offer over 50 different models and gear ratios.

There are numerous ways to mount these gearmotors; Figures 12A through 12C show a few of the ways. I used a miniature Firgelli L12-50-50- 6R linear actuator instead of a standard servo for the gripper as it made for a more compact arrangement.

Pettey and his team are customer-oriented and are very open to

suggestions from prospective robot builders. Their product line is constantly growing, and they aim to keep the robotics and mechatronics community supplied with as many parts and components as they can. Some have called ServoCity the ‘Home Depot’ of robot parts.

Robert Beatty and his two daughters built the Mars rover shown in Figure 13 with ServoCity parts. The robot rover was built for a museum exhibit in New York City.

Final Thoughts

80 SERVO 08.2013

FIGURE 13. Mars Rover for museum.

Though some of the ServoCity components and products might be a bit higher priced than you desire, you will certainly save a lot over trying to design and machine similar parts on your own. These components are very robust and intuitively designed.