(1) Bottom deck, (1) top deck, (2) servo mounts
(See text; precut chassis kit available at budgetrobotics.com)

2

2-5/8" Futaba-type hub wheels
Jameco: 2109624
Parallax: 28109
Pololu: Black: 226, Red: 227, Yellow: 228, Blue: 229
Solarbotics: #SW

4

3/4" × 3/4" plastic angle brackets
Budget Robotics: BRAC-GUS1
or
(2) servo mounts with brackets and hardware
Budget Robotics: SRVMT-203

{The plastic angle brackets and servo mount parts are included in the chassis kit noted above.)

Arduino Uno microcontroller
Jameco: 2121105
Pololu: 1614
RadioShack: 276-128
SparkFun: DEV-11021

1

Mini (170 tie-point) solderless breadboard
Jameco: 2109801        
Parallax: 700-00012
Pololu: 1490
SparkFun: PRT-07916

2

Continuous rotation servos
Jameco: 283039
Parallax: 900-00008
Pololu: 948 or 1248*
SparkFun: ROB-09347*

* The SpringRC servos are slightly larger than standard size, so the fit in the servo mount is a bit tight. They're made to snap onto Futaba-splined wheels, but it's a very snug fit. Press on with equal pressure around wheel. Do not force.

Some continuous rotation servos may require a "neutral point" calibration to keep the servo from slowly turning when it's in the stopped position. Refer to the documentation for these servos for additional information. You'll need a small (#0) Phillips screwdriver to make this adjustment.

2

Snap action leaf switch, normally open
All Electronics: SMS-196
Jameco: 1945268
SparkFun: COM-09414

1

4×AA battery holder, 6" pigtail leads
Parallax: 753-00001
Pololu: 1153
SparkFun: PRT-00552

1

9-volt battery snap, 6" pigtail leads
Jameco: 109154
RadioShack: 270-324

1

2.1mm power jack
All Electronics: DCSID
RadioShack: 274-1569

1

Piezo speaker (not a piezo buzzer!)
Jameco: 336314
Pololu: 1261 (100 Ω dynamic speaker)
RadioShack: 273-073

1

Infrared receiver
Parallax: 350-00014
SparkFun: SEN-10266

(Consider getting two infrared receiver modules, and having one as a spare.)

4-40 × 1/2" pan head machine screw

8

4-40 × 1/2" flat head machine screw

4

4-40 × 3/4" pan head machine screw

4

4-40 × 5/16" pan head machine screw

16

4-40 hex nut

4

#4 plastic washer

4

5/8" length nylon standoffs, 4-40 thread

6-32 × 3/4" pan head machine screw

4

6-32 hex nut

2

6-32 cap (acorn) nut

2-1/2" (typical) length standoffs, 6-32 threads

8

6-32 × 1/2" pan head machine screws

6" length female-female jumper wire
SparkFun: PRT-08430
Pololu: 1716

1

12" servo 3-wire servo extension
SparkFun: PRT-10373
Pololu: 780
Parallax: 805-00012

1

Breakaway double-sided header (set)
Pololu: 1065
Parallax: 451-00303

6" length 22-guage solid conductor insulated wire, 6" cable ties, Velcro tabs, double-sided foam tape, universal remote control (must support Sony VCR codes; most do), batteries, 0.25" O.D. rubber tubing (see text)