The media could not be loaded. This K’NEX EDUCATION STEM EXPLORATIONS: ROLLER COASTER BUILDING SET is challenging to build, but it’s a satisfying building set. It’s motorized, and it performs really well. It’s fun to watch the chain pull the roller coaster car up to the top of the tower. And of course it’s fun to watch the car do the curves and loops of the track by gravity when it’s released. It took me a couple of days, working off and on, to assemble this roller coaster. The K’NEX pieces are fiddly to join, and the drawings in the instruction booklet are hard to interpret if you’re new to the K’NEX system. (The “snowflake” connectors are confusing; the rods must be inserted “just so”; and the drawings sometimes change their directional perspective without warning.) What I really loved about this set, is that the roller coaster car will often go around the loop more than once without any help. Three continuous loops is fairly common. Whether the car continues to loop by itself seems to depend on where the “chain-grabber” underneath the car hits the chain—whether it hits an opening in the chain or not. If you’re aiming for continuous loops, it helps to hold the base down. The K’NEX rods are thin, so the roller coaster support structure is kind of flimsy. However, the connections are tight enough that you can pick the whole structure up and move it without destroying it. A few connections may come loose, but they’re easy to reconnect. The roller coaster is a large structure (30” wide, 16” deep, 25” high), so you need quite a bit of space to build and play with it. The three experiments (one included in the box, two downloadable from the K’NEX web site) add to the educational value of this building set. The first experiment suggests adding different amounts of weight to the car to test how added mass affects the car’s ability to run the loops. For the second and third experiments, you rebuild the coaster into a long gravity ramp, and then into a half pipe, to learn more about how a car behaves on a straight or U-shaped track. Neither of these builds makes use of the motor, which is why the roller coaster build is far and away the best. When you open the box, keep the contents of each bag together, more or less. You’ll save time if you don’t dump all of the pieces out in a big pile on the tabletop. The pieces that are the same type are grouped together in the plastic bags—chain links, rods of certain lengths, red connectors, blue connectors, spacers, etc. When I’m assembling a big project like this one, with a lot of pieces, I use disposable plastic dinner and salad plates to hold the similar, or the same-colored, parts. A nice thing about this K’NEX set is that each different type of connector is a different color (the orange connectors are different from the yellow connectors, and so on), so it’s enough to check the color of the piece when you’re following the instructions.
