Tamiya Terra Crusher

Terra Crusher (TG-01) is a radio controlled nitro engine (glow engine) powered 1/8 scale truck released in July 2002, by Tamiya Corporation of Japan.

ignificance

Terra Crusher was an attempt from Tamiya aimed at nitro RC truck market, dominated by American trucks such as T-Maxx from Traxxas. The popularity of T-Maxx was overwhelming and it started an off-road monster RC boom. Responding to the popularity of this new segment, other manufacturers such as Tamiya and Team Associated developed of nitro trucks that could compete with T-Maxx. Terra Crusher had all the strong points of T-Maxx, and had to offer more to compete. Terra Crusher thus featured all the major features of T-Maxx, such as big tire 4x4 with two shocks per tire, in 2 speed transmission, as well as reverse gear and on-board starting system. In addition, Terra Crusher was much bigger. T-Maxx weighs 4kg, Terra Crusher weighs 5.7kg. Terra Crusher was offered at about the same street price of $400. To lower the production cost, Terra Crusher had 2 channel radio set instead of 3; lacking this extra gear meant that reverse was done with a differential gear.

History

Tamiya's first nitro truck, and first nitro vehicle, was TR-15, released in 1994. TR-15, along with its 0.15 engine started Tamiya's nitro RC line. TR-15 was a 2 wheel drive stadium truck. RC electric vehicles offered the more popular 4x4 system. Next was Mad Bison, released in 2000. It was simply a 4 wheel drive on-road car with off road tires; a reduction gear that bulged under the chassis bottomed out easily). Unlike these two predecessors, Terra Crusher was built from scratch, built to take on world's most successful nitro truck at the time. New to Terra Crusher were a double wishbone suspensions with 2 shocks per tire, differential for reverse gear, on-board starting system, and telescoping universals.

Mechanical Design

Terra Crusher's was built to compete with T-Maxx and thus TC's design was sound. Two extra long shock absorbers were installed on each double wishbone suspension to ensure long soft travel. 2 speed transmission and reverse worked differently from T-Maxx. Differential gears in the center worked as a reverse gear and 2 speed was centrifugal gear change. 2 channel radio meant that one throttle servo worked to increase/decrease engine RPM, brakes, reverse gear. This complex throttle design was clever, however a bit difficult to set up.

Design Flaw

Mechanical design itself was sound. Wild Commando, TNX both have same design, and they are excellent vehicles. However, 175mm tires on Terra Crusher proved to be too heavy for 3cc engine. Each wheel and each tire weighed between 500-600 grams. All four would weigh over 2kg, just as much as one entire on-road car. Another large sized truck from another manufacturer, Team Associated, called Monster GT, has tires with same dimension, but they weigh much less. Simply by installing Monster GT's tires, Terra Crusher's weight problem could be readily remedied, as TNX in recent years have proved. 3cc engine was only slightly bigger than 2.5cc engine of T-Maxx, however, that increase was not sufficient to overcome the doubling of the total mass. In addition, exhasut manifold was right angled. In two-stroke engines of these RC trucks, exhaust has an important function. Explosive exhasut would go to the end of the tuned pipe and bounce back into the combustion chamber. L shaped exhaust manifold of Terra Crusher engine hampered the effectiveness of tuned pipe, further weakening the engine's performance.

Immediately after the release of Terra Crusher, it was evident that Terra crusher suffered under the weight of massive 175mm tires and lack of power from 0.18(3cc) engine. [cite web
url=http://www.tamiya.com/english/products/43501terra_crusher/terra_crusher.htm
title=4x4 Customized Monster Truck Terra Crusher
publisher=www.tamiya.com
accessdate=2008-06-18]

Tamiya corrected the flaws by simply releasing Wild Commando with smaller and lighter tires only a few months after the release of Terra Crusher.

Legacy

Wild Commando (TGM-02) was released in the fall of 2002, only few months after the release of Terra Crusher. It was completely idential to Terra Crusher, but equipped with much lighter and smaller tires. That alone reduced weight from 5.7kg to 4.8kg and improved performance greatly. The same small size tires were sold separately for Terra Crusher. However, smaller 144mm tires that were better suited for on-road races were not popular for fans of Terra Crusher who wanted a rugged off-road monster truck. [cite web
url=http://www.tamiya.com/english/products/43503wild/index.htm|title=1/8 Factory Assembled Glow-Engine R/C Wild Commando|publisher=www.tamiya.com|accessdate=2008-06-18]

TNX (TGM-03) was released in 2004 proved that Terra Crusher's basic mechanical design was a very sound one. TNX is almost identical to Terra Crusher, aside from a few upgrades, notably stronger O.S designed 1.8 (3cc, up from 2.5cc) glow engine, removal of electronics box and employing much lighter tires. TNX 148mm tires were smaller than Terra Crusher's 176mm but bigger than Wild Commado's 144mm tires, going back to the off-road category. Reverse gear in Terra Crusher required delicate-tuning and was abandoned from TNX. Terra Crusher's 5.7kg (12.5 pounds) weight was reduced to 4.4kg(9.7pound) in TNX. TNX quickly proved that it is a very capable racing truck by winning numerous races. [cite web|url=http://www.tamiya.com/japan/info/050823madness/index.htm|title=TNX、アメリカで圧勝|publisher=www.tamiya.com|accessdate=2008-06-18]

TNX 5.2R (TGM-04) is basically same as TNX, but mounts a larger and powerful 5.2cc engine, instead of 3cc engine. Aside from engine upgrade, also a few minor modifications are made to improve upon the performance of TNX. Weight was further reduced to 4.3kg. Dual shocks were simplified to a single shock, universal shafts were also simplified to dog-bone type universals. On-board starting system was abandoned for handheld starting motor, which saved weight. [cite web|url=http://www.tamiya.com/english/products/43530tnx5_2r/index.htm|title=4×4 Monster Truck TNX 5.2R|publisher=www.tamiya.com|accessdate=2008-06-18]

Nitrage 5.2 is the most race worthy truck that was released in the summer of 2007. It uses the same 5.2cc engine, but the truck is redesigned around 5.2 engine, geared toward adjustability of many parts for off-road racing. Chassis uses shallow tub construction, removing the necessity for bulky support beams from TNX. This lowers the center of gravity, and makes Nitrage more "race ready." Double wishbone suspension allows adjustment of camber angles. 2 speed transmission is also abandoned. Due to 5.2cc engine's ample power, speed change is not necessary. Plastic shock towers of TNX were replaced by aluminum shock towers. Weight has increased slightly to 4.6kg. Over all, Nitrage has adopted many lessons learned from various races TNX has taken part in. [cite web|url=http://www.tamiya.com/english/products/43532nitrage5_2/index.htm|title=XBG Nitrage 5.2|publisher=www.tamiya.com|accessdate=2008-06-18]

The Future

Nitrage 5.2 is completely newly designed next generation nitro truck from Tamiya. While its design looks similar to Terra Crusher and TNX, upon close inspection, the adjustability added to the new design is reminiscent of 1/8 buggies. Just as Tamiya had jumped into nitro truck market with TR-15 and Mad Bison, Nitrage 5.2 can provide an excellent platform to allow Tamiya into the coveted 1/8 buggy market.

Footnotes