Review on Wooden Roller Coaster Marble Run Puzzle - ROKR 3D Mechanical Model For Self-Crafting, Decoration, And Educational Gifting by Jeff Morris

Another challenging and satisfying wooden mechanical kit from Rokr. I found this to be more involved and difficult than the Rokr Pendulum Clock I built previously. In addition to a base, support structures and multiple marble ramps, the marble run is made of up three complex subassemblies: a hand cranked gear mechanism, an escalator mechanism and a stacked ramp mechanism with swing gates. Not only are there a lot of small parts in each subassembly, but the final building stage of each involves a tricky bit of alignment - you have to keep track of multiple slots, holes and freely moving pieces. They all have to line up perfectly in order for everything to click into place. The gear mechanism wasn’t too hard. But finishing up the escalator and especially the swing gate subassemblies was quite challenging. If you’re mechanically inclined and/or used to intricate model kits, this challenge can be enjoyable. I’m both, so it was deeply satisfying. But I can see how others could find these alignment tasks tedious and/or frustrating.As in my review of the Rokr Pendulum Clock, the quality of the laser cutting is impressive. Also mirroring my earlier review, Rokr includes extras of many of the small parts. This is a really nice touch that more companies should emulate.More so than the pendulum clock kit (which is mostly made up of parts oriented in a series of stacked, parallel planes), the marble run has a lot going on in three dimensions. There are structures hanging off other structures at right angles. Which means that assembly sometimes requires applying force in multiple directions, or against structures that aren’t that easy to get a finger behind to apply counter pressure. It's difficult to put into words, but suffice it to say you need some fairly decent finger dexterity and hand to eye coordination.ETA: I should say that while the Rokr Marble run was a more complex build than their pendulum clock, it didn't require nearly as much post-construction tuning/adjustments to run properly. That's a big part of the challenge with the clock model. With the marble run, it pretty much worked from the start. Aside from intermittent sticking of the escalator compartments (referenced in the Tips section, below), all it needed were a few tweaks to the ramps here and there when marbles would initially get hung up.Once assembled, the marble run is delightful in operation. There’s really a lot going on. In addition to ramps, chutes and the aforementioned escalator (truly, a marvel of engineering), the complex design allows marbles to do different things depending on whether they are the first, second or third object to travel down a particular path. The more you watch, the more complex and varied the mechanism becomes.Tips:A razor knife is very helpful to slice through those tiny sections of plywood that are deliberately left uncut (to hold the pieces in place during packing/shipping). It’s possible to detach them without a knife, but you’re more likely to damage them.A lot of these pieces look *very* similar, are complex in shape, and must be oriented correctly. Confirm part numbers before separating and re-confirm as you put them together. Pay particular attention to the parts on the thinnest plywood sheet, labeled sheet "G”. There are dozens of tiny wooden ‘pins’ that all look very similar, especially after they are separated from the sheet. But they have different lengths which are critical to proper assembly.Rokr provides a wax stick to lubricate certain moving parts. Definitely lubricate all the areas identified in the instructions. But one place not identified are the fronts and backs of the individual compartments that carry the marbles up the escalator. They rise and fall right next to each other. Occasionally one gets hung up on another and doesn’t descend when it’s supposed to. Take a few moments *before* final assembly of the escalator mechanism to apply a bit of wax to where the compartments slide past each other. I tried doing it after assembly and by that point it’s really impossible to get the wax everywhere it’s needed.