Servo - April 2012

The version 3 base with batteries installed.

get at least two more boards on the robot. This version switched to a 40-pin OEM style BASIC 2p40 Stamp, but was upgraded to accept a Propeller processor for even higher performance. Just about any processor could be used if you have one you’re more comfortable with.

In order to keep tabs on the battery voltage, I picked up a small voltage monitor meant for RC equipment. It is switchable for either 4.8V or 6V. This can go on the back of the second level and mounts to the battery holder. With it installed, it is easy to tell how the battery is doing and it provides a cool display. It clearly shows the load on the battery increase whenever the servos are moving, and when other circuits are active that draw a noticeable amount of current.

Now with a slick platform, it was time to expand upon that. For line following, a pair of the QTI line sensors were added under the base at the front of each of the SpindleBots. Some of the self-tapping screws recycled from an HP inkjet printer were used to secure the QTI sensors to the underside of the base. There are lots of options for sensors these days. With the tall 100 CD spindle, you can build a robot bristling with a wide array of sensors. One of the next things I plan on adding will be small XBee modules to let all the SpindleBots talk to one another and work as a group.

I haven’t tried using a 10 CD/DVD or 25 CD/DVD spindle but I’m sure that someone will make one into an interesting robot. To help classify any new SpindleBots out there, I’m going to put forth the following size guide which is very reminiscent of the old floppy standard: 25 CD/DVD case 1/4 height; 50 CD/DVD case 1/2 height; and 100 CD/DVD case full height. I recently spotted a short 10 CD/DVD spindle case. I guess that could be classified as a 1/8th height spindle.

That’s a Wrap

There is now a whole new class of robots that you can build, and I think these will be great in a classroom environment. In a classroom setting, it could help teach an

The version 3 base with battery holders.

interesting way to recycle and/or re-purpose many parts. Those that can’t be used could be identified by the material type (metal, plastic, etc.) and then recycled. It would help teach students about the types of materials used to construct an inkjet printer and how those same materials can be recycled.

If you build your own SpindleBot, I would enjoy seeing a picture of your robot or hearing from you. Whether you are building robots for school or just a hobby, I hope you find building your own SpindleBot as fun and rewarding as I did. SV