Getting back on Track: Continuous Linked tracks in 2017 LEGO Sets.

Over the last few weeks, life has been getting a bit busy, and interfering with my ability to get to the keyboard! Not an excuse. Just an explanation. And not a very clear one either! Anyway: Perhaps it is time to get back on track…


Continuous, self propelled tracks were first conceived in the 1770’s, but it was probably not until the early 20th century that they became a method of choice for moving heavy vehicles such as tanks, bulldozers and Antarctic exploration vehicles across soft, uneven ground. The term ‘Caterpillar tracks’ was trademarked in 1911 by Benjamin Holt.  Such tracks have featured in LEGO sets or either as continuous rubber bands, since 1969 and as interlocking linkages since 1974 (Element 273).



The links we are used to today were introduced in a slightly different form in the early Technic sets – particularly the 856 Bulldozer(part 3873).  They were in production until 2009, and were then replaced the following year by the current version (ElementID 6047885) , with slightly beveled edges.

Meanwhile, back in the future…

Earlier this year, I quietly picked up the most  excellent LEGO City set, 60159 Jungle Halftrack Mission(376 elements; ($AU44.99; $US39.99; 29.99€). By quietly, I mean I picked it up and built it, without really telling anyone or reviewing it in public, beyond putting a few pictures up on Instagram.  With two adventurers, a panther, temple and two vehicles, retailing for around $AUD45, this set has great play value.  The set’s eponymous half track provides a few interesting techniques, not the least of which serves to ensure that a child pushing the vehicle on the ground does not have to worry about the tracks just slipping on a smooth surface: attached to the same axles that turn the gears attached to the tracks are wheels with tires, which are hidden, but provide the primary contact with the ground.

ha;f track


 Not only, but also…


While accumulating parts for Mystery Project X ( whose identity will become apparent in due course), I picked up another of this year’s NEXO Knight’s sets: 70354 – Axl’s Rumble Maker (389 elements; $AU44.95; $US 39.99; 39.99€). This is a terrific set, with a number of fantastic play features: a half track vehicle with detachable jet (complete with swing wings and reversible cockpits); duel drilling mechanisms as the vehicle is pushed along, and a fashionable flame yellowish orange colour scheme. We also get Axl, an Axl Bot, Rogul (again with the great swooshy base instead of legs) and a small, comical Brickster.

IMG_8079.jpg Like many of this year’s NEXO Knight sets, it can attach in some way with the Power Suit Knights released earlier in the year.  In this case, we remove the Power Suit Legs and attach the upper part of the body to the tracked section. Unfortunately, I don’t have Axl’s Battle Suit, but let us put Axl into Robin’s Battle suit from the NEXO Knights ‘Build your own Adventure’ Book, and see the overall effect: perhaps not as nifty as with some of the other battle suits, or indeed other sets such as 70348: Lance’s Twin Jouster that we looked at last week, or Macy’s Drop Bot Dragon, which will feature in this solitary photograph…



A Tale of Two Halftracks.

The tracks in both of these sets consists of treads made up of  ‘Chains M Plate M, with 5 2.8mm holes’. Compared with rubber treads, long chains of these links will slip relatively easily on a smooth, hard surface.  Sometimes, alternative driving mechanisms are used – such as the ‘dummy wheel’ in the Jungle Halftrack Mission.

The Rubber friction spots, provided with the Fortrex and Boost Creative Toolbox.

The NEXO Knights Fortrex, as well as Boost Creative Toolbox use larger treads (Design ID 88323), which will still slip on those smooth surfaces.  To increase the friction with the ground surface, these sets use rubber studs (24375), which plug into the holes on the tread plates.

The tracked part of Axl’s Rumble maker, is however constructed a little differently to the City set.  While our City set simply wraps the sprockets of the chain around the teeth of the gears, we have a more complicated arrangement: Two, twenty toothed cone wheels facing each other, and mounted to the frame with the aid of low friction connector pegs.  The gear chain sits nicely with the connections between the gears meshing with this cone gear arrangement.


And the wheels turn quite freely, especially compared with the half track. In fact, a gentle push and it zooms across the room.

By the way, I recommend the play value, and joy of building for both of the sets discussed here today. (They each earn four out of five Arbitrary Praise Units)  Perhaps I am seeing a little more versatility in the parts from the NEXO rather than the City set, but they have different target audiences, and have different goals.

Now, does any of this bear the slightest relevance to Mystery Project X? No. Not at all.  Perhaps I will take you for a run down that rabbit hole soon, but come back next time, when we will look at the latest LEGO Ideas set to be released: Women of NASA. Subscribe to the blog, or follow the Rambling Brick on Facebook to receive notification of new posts.

Until then, play well.



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