Today we’re building a study model of German engineer Karl Benz’s gearbox, the same mechanism you’d find in the transmission of any modern automobile, complete with drive shaft, layshaft with gear couplings, reverse idler, and a gear shift.  It’s the UGEARS Gearbox (available direct from UGEARS here), the second model we’re testing after the 2-in-1 Arithmetic Kit (check out our first UGEARS review here).  The Gearbox is part of the model maker’s STEM Lab series, educational tools and fun models that aren’t just for kids.  Anyone who has ever driven a car should know the fundamentals of how a gearbox works, and this model is an excellent start.

The five laser-cut sheets of plywood, punch-out tool, and wax are all you need to build this gearbox.

The box includes everything you need two make the 3D, working, plywood gearbox, 5 sheets of pre-cut plywood, a piece of wax crayon to reduce friction, and a press-out tool to ease removal from the sheets of smaller pieces.

A look at the box and what’s inside.

Making the gears is pretty clever, consisting of small wooden teeth that slide into place.

The box suggests these box can be built in 1-2 hours and we found making this slower made more sense–it requires many parts to be rubbed with the wax stick, and if you don’t align the gears exactly right you will have problems later.  The recommended age for building this model is 8 and up.

Application of plenty of wax in the gear teeth will help smooth the running of the gears together.

The instructions were clear (written, with color visuals), and available in 9 languages, and an augmented reality option (QR code links provided) is included for further learning via a UGEARS app.

The model is surprisingly sturdy.  Each cog is reinforced, with some three layers of plywood thick.  We didn’t need to sand anything.

The resulting sound is that clickety-clack rumble of vintage early 20th century motor cars.

The project about two-thirds complete. The rubber band is not a belt, it’s cut into pieces to form “feet” to keep the final model in place.

The only skills required are patience and a gentle touch when punching out the 120 total parts.  Most operations are tongue and groove fastening, along with reinforcements via pegs, along with axels and gears fitted with teeth.

As with the first build, following directions is a must.  But even following the directions we had three plywood breaks.  Fortunately they did not affect the functioning of the model, and worst case, could have been repaired with Elmer’s or wood glue.

And a close-up of the final model before adjustment (above).  Instructions and examples are provided to demonstrate how and why each component works.  Select gears I, II, III, or reverse via the kinematic pair of gears with different ratios and, rotating the actuator handle clock-wise, you can watch and control the rotation speed of the layshaft and drive shaft.  In a position “N”–idle– in which both clutch gears of layshaft remain uncoupled and idling; the first gear makes the layshaft and gears rotate with the lowest speed; the second gear lets the drive shaft along with the flywheel rotate with an average speed and the third gear allows the layshaft and all gears to rotate with the highest speed.  Switch on the reverse gear and see how the driving clutch gear moves to the left towards gear “R” and connects to transfer the rotation to the lower gear mechanics and propel the layshaft and all gears to rotate in reverse.

The sound tone changing from the different speeds of the motor might be the most impressive feature–the pitch changes just like you’d hear with the different gears when shifting a car in motion:

The model, at least as we built it, slipped gears from time to time (it catches in third gear in the video), and trying to correct for that in the build can be part of the learning process–pull off the console cover and confirm positioning of the gears.

The UGEARS Gearbox project took about four hours over three sessions, more than our first UGEARS projects, as it’s more complex than the arithmetic model of the Multiplier and Addiator (reviewed here).

Even better than the 2-in-1 Arithmetic Kit, the UGEARS Gearbox can be a powerful tool for young learners and part of a great science and technology desk set for engineers–and it’s affordable, as of the date of this review it’s listed at about $20.  The Gearbox is available here at Amazon.  In the next few weeks look for builds of a UGEARS Variator, a Tachometer, and a Random Generator, plus one of the advanced build sets.  Take a look at all the available UGEARS models here at Amazon, and check out the UGEARS website.

C.J. Bunce / Editor / borg