A model steam engine or toy workbench won’t guarantee a child will pursue a technical career. On the other hand, it can’t hurt and might be a lot of fun besides. So here are some toys and kits that could spark the imagination and perhaps launch a career.

Watch (and hear) your Harley engine in action
This half-scale plastic model might not power your motor scooter, but it won’t drip oil on the carpet either. The kit includes over 150 parts that go together to build a 13-in.-tall replica of a Harley-Davidson Twin Cam 88. It includes clear external parts that give a view of key internals. And those internal parts move and turn, demonstrating the mechanical operation of the real engine. Major components include the crankshaft, pistons, rods, rocker arms, valves, and camshafts. Chrome parts and a display base are also included. There’s even an electric motor operated by 3 AA batteries to put the model in motion and includes a sound-card recording of a real Harley-Davidson Twin Cam 88. The $100 model, which is said to take an “experienced” modeler to complete, is from Testors Corp., (800) 962-6654, testors.com.

Dogfight in the living room
The FlyTech Bladestar, a battery-powered indoor flying machine with a 12-in. wingspan, comes with an autopilot that uses an onboard sensor to avoid ceilings and obstacles. And if the autopilot fails, the aircraft is made of light, highly flexible material, so it should withstand any crashes and not damage your living room much. The craft can also hover. The remote-controlled vehicle comes with a dogfight accessory. It lets you fly and fire against a similarly equipped Bladestar. Score a hit when in range, and your opponent goes down.

The Bladestar flies 5 min on a charge, and recharges in about 20 min. But recharging is simple; it takes place through the remote. The three-channel digital IR remote takes six AA batteries. It also comes with spare blades and propellers. The Bladestar costs about $40 from WowWee, (800) 310-3033, wowwee.com.

Think in 3D
Dado Cubes aim to combine art and science, helping kids of all ages explore principles of proportion, balance, structure, and color. A twist on classic building blocks, Dado Cubes are shaped like open boxes with slits on the bottom. The slits interlock, letting kids create an almost unlimited number of 3D structures. The cubes are intended to “bolster visual spatial intelligence and problemsolving capabilities through design-centered activity.” In a word, Dado Cubes are a simple design intended to inspire complex thought. Each set includes 10 nested cubes, scaled from 1 to 5 in. The Cubes meet or exceed the mechanical- hazards requirements of 16 CFR 1500, Federal Hazardous Substances Act Regulations and ASTM F963- 03, Standard consumer specification for toy safety. Each set costs $27.50. They come from Fat Brain Toy Co., (800) 590-5987, FatBrainToys.com.

Let wind power blow you away
The Wind Power kit lets kids and other tinkerers build a wind turbine, learning about the physics behind windpower generation along the way. A colorful, easy-to-understand 35-page instruction book guides budding anemologists through over 20 experiments that explore gear ratios, wind speeds, and blade count, angle, and profile.

Along the way, kids discover how wind is generated, how to calculate work and power, how to determine wind power and apparent wind, and how to identify and combat turbulence. Users can configure the kit to winch up a weight or heavy item, power an LED, or recharge an AA battery (not included).

The 30-piece kit is for children ages eight and up and costs about $50. It’s from Thames & Kosmos LLC, (401) 683-5535, thamesandkosmos.com.

Head and torso anatomy puzzle
A kit for kids age 8 and up contains plastic puzzle pieces that go together to form a 4D model of the human torso and head. The manufacturer calls the model “4D” because it is made up of 3D pieces with fine details. Each kit contains 32 pieces, including body parts such as a skull, brain, backbone, liver, stomach, and large intestine. The durable pieces snap and slide together securely, so solved puzzles show what the inside of a body looks like. An enclosed instruction sheet illustrates how parts fit together to build the 5.5-in.-high model. It also says beginning users typically take about 30 min to snap together the pieces. The puzzle comes from MindWare, (800) 999-0398, mindwareonline.com.

Hot Stirling engine keeps things cool
Something cold, something hot. That’s all you need to drive the Stirling engine that spins this kit’s fan. The engine, invented and patented in 1816 by Dr. Robert Stirling, runs on a sealed cylinder of air.

A heat source and heat sink alternately expand and contract the gas, moving the piston and driving the crankshaft. The heat source can be an open flame, a sun-warmed surface, or the palm of the hand. Ambient air serves as the heat sink. The engine is said to be more efficient and quieter than internal-combustion engines and safer than steam engines.

The kit contains small parts and is not suitable for children under 15. It costs about $50 and is made by German company Inpro Solar, inprosolar.de, (011-82-08) 95-84-50. In the U.S., contact Think Geek, thinkgeek.com, (888) 433-5788.

Spy cams go all-terrain
The Spy Video ATV-360 is perfect for stealthily checking up on office break rooms and competitors’ R&D labs*, not to mention little brothers. The radio-controlled vehicle transmits real-time audio and video up to 75 ft. Spies receive surveillance signals and monitor them using a headset-mounted LCD and a single earbud.

The tanklike vehicle can power over uneven terrain and climb low obstacles for a better viewpoint. Dual-track drive permits quick course changes and retreats. A button on the controller spins the camera and microphone 360° to detect threats from any direction.

The transmitter, receivers, and vehicle require a total of 12 AA batteries (not included). The mobile spy-cam is recommended for children eight and up. It retails for $130 and comes from Wild Planet Entertainment Inc., (800) 247-6570, wildplanet.com.

*Editor’s Note: Machine Design does not condone nor recommend industrial espionage.

A mechanical inch worm
The remote-controlled “Meka-Inchworm” uses crank assemblies to creep its way along. The legs of the Inchworm consist of three parts: fore, hind, and center. The fore and the hind legs touch the ground first while the center legs are in the air when the machine is moving. The center legs touch when the fore and hind legs return to their positions, or while making a turn. There is no soldering involved, but this is a kit for adults. The assembly instructions can be downloaded from the online supplier, makershed.com. They reflect the occasional unintended humor of a Japanese translation that, among other things, warns “do not point your hands and eyes with the screwdriver.” The kit, part of Mechanical Animals Series from Gakken, a Japanese company, lists for $69.95.

Cramming and jamming
If your kids like to “cram and jam” (that’s kid-speak for studying while listening to music), then check out the Crammer, a handheld study aide that’s also a portable music and game player. Aimed at the third to eighth-grade levels, the Crammer combines flash-card-type learning drills and quizzes with the ability to play MP3, WAV, and Ogg Vorbis sound files. It also contains several computerbased games designed to improve shape recognition and hand-eye coordination. It plugs into your personal computer via the USB port so you can download study materials, personal music files, and over 16,000 quiz questions based on leading textbooks from the Crammer Web site. If you can’t find any suitable study materials or questions on the net, software on the site lets you create your own. The Web site also lets parents keep tabs on their child’s progress. The Crammer is about $60 from Leapfrog Enterprises Inc., leapfrog.com.