Based on drawings from Da Vinci's Codex Atlanticus, this Pathfinders catapult kit uses a pair of bent wooden arms as springs to launch clay balls (included) over (4) meters at enemy fortifications (not included, go make your own enemies). The assembled model will be approx 9" tall on a 10" x 7-1/4" base. Made from pre-cut, untreated wood from sustainable forests, and built with pegs for added strength and verisimilitude. A 2013 Creative Child Magazine Top Toy of the Year Winner and a great resource for STEM activities. For ages 12 and up.

Everything you need to build a little DC motor is included in this kit (except sandpaper, screwdriver, scissors and, of course, an AA battery). The instructions are simple and explain the theory as well as assembly. Fun and educational for ages 12 and up.

His name is Tobbie II, and although he stands only about 6-7/8” tall, he does sport (6) actual feet, which is why he has such an agile, 360-degree, free-rotation body. You build him yourself (easy-peasy if you’re over 10) and program him on your computer, tablet or smartphone. Comes out of the box pre-programmed with Assembly Checker and Program #1, so the fun starts right away. Use him as a light tracker or thermometer, or to play rock-paper-scissors or bowling, or as a notice board, calculator or compass, or as a pet who will follow you. He’ll do other things, too. Includes a 36-page manual, and all you add is a quartet of “AAA” batteries and some common hand tools.

Could be a new line of cologne, but in fact, it’s a clever kinetic action demo kit called Wave Wires® with magnets marked for polarity, and mounted on (4) 8-1/2” long wires attached to a 4-1/4” square steel base. Includes a dozen 1/2” dia steel disc weights, an acrylic ring and an 8-page activity booklet. The attraction/repulsion magnetic properties cause the magnets to swing on top of the wires like old-time circus acrobats. Ages 8-14. Really cool, if we don’t say so ourselves.

You can’t start fooling people too early. This box of tricks is for budding magicians, and includes the props and instructions for (77) tricks. Includes a magic wand, without which you can’t be a magician, plus assorted cups, balls, cards and coin-trick frames. You add a few things like money, a handkerchief, gullible friends, etc. For ages 6+.

Physics faculty alert: It's very small, but teaches a powerful lesson, this little diamagnetic-properties demo kit. You get (4) plated magnets, each 1/4" square x 3/32", and (2) 1/4" square pieces of graphite to float above them. The graphite may have slight chips along the edge but that won't affect the effect. Includes instructions/fact sheet.

The Tumbling Robot Experiment is relatively easy to assemble and has sensors in his (her?) belly, back and legs so he (it?) can fall and get up again, like some of us humans. At 8" tall, in between tumbles, it's a manic, sliding, chomping, swinging thingy, like a droid cookie monster in a Pilates class. You put a pair of "AA"s in his feet. Ages 8+.

Home robotics, bubeleh. Build a working hydraulic arm with this excellent 66-piece kit from Pathfinders' Simple Machine series. Structure is die-cut plywood and the kit includes tubing, (3) syringes and glue. You'll need a ruler and scissors. The finished arm will be approx 13-1/2" tall and will reach out over 16" and rotate 90° on an 8-5/8' x 6-7/8" base. Comes with a 12-page manual and uses water. Beautiful, too. For ages 8+.

From Fascinations®, these small model kits are made from intricately laser-cut polished steel. Punch the pieces out from the 4-1/4" square sheet and put them together with the tiny tabs. You pick the dragonfly, with a 4-1/2" wingspan or the Black Pearl pirate ship, approx 3-1/2" long. For ages 14+, because they take plenty of small motor skills.

It's small, as actual solar systems go, and you have to assemble it, but still…. You snap together this (not-to-scale) model of our solar system, paint it, and position the pieces. You get (6) colors plus a tube of glow-in-the-dark paint and a brush, the (8) planets (Pluto didn't make the cut, remember), and cardboard rings for Saturn. Sizes range from just under 1/2" for Mercury to the 1-7/16" sun. The finished model is articulated and stands approx 4" tall x 12" across on a 3-7/8" dia gray plastic base. Ages 8+.