Make a whole bunch of fun and instructive Lego® machines/chain reaction models like marble runs and mousetraps involving ramps, buckets, funnels balances and much more. Comes with (33) Lego® elements, (6) Lego® balls, a dozen paper props, and a 78-page instruction booklet for (10) machines. You add a few common household items. Includes suggestions for more complicated devices if you have your own Lego® pieces, and if you don't, what are you waiting for? Ages 8+.

Lego® goes crazy with this 100+ piece kit with everything you need to build (16) different contraptions (be pretty stupid if they made 16 of the same contraption) for your amusement. In the mix are gears, pulleys, belts and axles, which you could turn into a rocket racer, Lego® launcher, donkey cart or scissor grabber, among other things. Includes a 50-page spiral-bound graphically illustrated instruction booklet. And, yes, adding Lego® pieces of your own just ramps up the fun. For ages 7+.

Among other things. (Sorry, no oranges.) Our each is a set of (4) laser-cut moving wooden gear models from U-Gears®, including a cat, a tractor, a human head and a heart. You like to fidget? Us, too. Each has (6) or (7) laser-cut parts and will fit in the palm of your hand when finished. They’re like worry beads in that you'll find yourself playing with them to help you inch toward inner peace. They’re press-fit, so no glue or tools needed. For ages 5 and up.

Wood or wooden you like to never see another pun on wood or wooden? Too bad--we’re not even trying to quit. Meanwhile, you can select your favorite from our collection of wooden automatons that you crank to move, all made from laser-cut pieces that you peg or glue together. You pick: the wooden clapping monkey, approx 6" x 3" when assembled; the wooden wiggling fish, 10-1/4” x 8-1/4” x 4-3/8”; or the wooden drummer drumming, 6-3/4” x 4-1/4” x 2-3/4”. All come with instruction booklets, glue, sandpaper and wax, and are for ages 9+.

Right after you build your own working medieval catapult or trebuchet. All you’ll need is glue, scissors and a steady hand (plus a small bag of marbles or rocks or something as a counterweight for the trebuchet) to construct these wooden, Canadian-made siege engine kits. The catapult stands 6” tall x 5” wide x 10” long and will toss assorted stuff 15 feet or farther, depending upon the stuff. The finished trebuchet will be 26” long x 18” wide x 24” tall and will propel small objects (meatballs?) 20 feet or more. Both include detailed instructions and are great resources for STEM activities. For ages 9+. Note: Please don’t propel small mammals, and please don’t put anyone’s eye out.

Nice little pulley unit kit includes (1) pulley each at 50, 30, 25 and 20mm and (3) pulleys at 11mm, plus myriad bushings, a 3VDC motor, (2) belts and a belt guide, base, mounts and assorted hardware. Includes graphic assembly instructions, plus a couple of rudimentary drawings with suggested projects. It's a mechanical science project waiting for a home.

This multi-bot solar kit includes a 1.5V solar cell, a small DC motor and gearbox and a boatload of parts that will let you make (14) different solar-powered projects including: a turtle-bot; walker bot; quadru bot; wheel bot; boat bot; beetle bot; dog bot; auto bot; carb bot; slither bot; roly poly bot; surf bot; and, you should pardon the pun, the row bot. No, really--there's a row bot. Projects come in (2) levels of difficulty and include an 81pp graphic manual. You'll need a hobby knife or a pair of side-cutters, and sunlight. Most projects will be approx 5" tall when assembled.

From Metal Earth®, the people who make shiny metal 3D models, now comes the Doctor Who metal models. All punch-outs with no glue or soldering required. You pick: the Golden Dalek, at 2-1/4” x 3” x 1-1/4”; or the Blue Tardis model at 1-5/8” square x 3-1/4” tall. And if you don’t know what a Dalek or Tardis  is, you shouldn’t even be reading this. These are challenging models, so rated for all ages over 14.

Who woodn’t, really? In a world of plastics, it’s hard to beat a model fashioned from pieces of dead trees. You pick from our assortment of pre-cut unfinished wood models made for ages 8+, and all you add is wood glue, paint, sandpaper and simple hand tools: the 12-piece drag racer will measure 6-3/4” long x 2” tall; the 35-piece steam engine will measure 7-3/8” long x 4-3/8” tall; and the 46-piece stage coach will be 8-7/8” long x 5-7/8” tall. (Sorry, no horses.)

It doesn't get much cooler in the robotic-arm-kit game. The assembled arm is 15" tall x 9" long x approx 3-1/2" wide. It's 2-pronged hand opens to 1-3/4", lifts up to 3.5 oz, swings 120 degrees at the wrist, pivots 300 degrees at the elbow, and sits on a base that swings 180 degrees up and down and rotates 270 degrees, like, well, an arm. Controlled by (5) 2-axis joy-sticks and powered by (4) D-Cell batteries that you provide. Includes a hand-mounted light and over-torque and gear-breakage alarms, which is more than your arm has. Requires simple hand tools for assembly and is made for ages 13 and up.