Tamiya J.G.S.D.F. Type 74 - 49533 (Radio Controlled Model Review)

  Released by Tamiya in 1993, the Japan Ground Self Defense Force Type 74 (#49533) came as a Full Kit.

  Development began in 1970 and the final tank version was officially adopted as the Type 74 in September 1974. The tank featured the NATO standard type L7A1 105mm main gun, that was produced by the Vickers company in Great Britain. This gun uses a coaxial buffer, developed by the Japan Steel Works Ltd. The main gun unit is mounted in a low profile cast steel turret and matched to the latest fire control system, comprised of a laser range finder, trajectory computer and gun stabilizer. An infrared viewer is also used for efficient night operations. The running power for the Type 74 tank is supplied by Mitsubishi Heavy Industries Ltd. And is the Type 10ZF22WT, air cooled, V10 cylinder 2-stroke diesel engine, which is capable of 720 horsepower. The air and hydraulic suspension system incorporates a height control system to lower its profile even more during stationary combat conditions.

  This model comes with metal bushings, that after a short while, when dust and grit get into them, can actually wear into the metal drive shafts that spin in them - we recommend these should be replaced by a full set of steel shielded ball bearings ASAP.

Rating: 4 RCScrapyard

Rechargeable Batteries
for RC Models

   At the time this article was written, there are four types of Rechargeable Batteries that are commonly in use for Radio Controlled Models.
Ni-Cad (Nickel Cadmium) Batteries have been around the longest. My first stick battery, purchased way back in 1987 was rated at 1200Mah (Mili Amp Hours) and with a silver can 27 Turn motor my Tamiya Boomerang would run around in the back yard for a good seven minutes before slowly coming to a stop. Ni-Cad development continued until around 1998 to a maximum rating of around 2000Mah and matchers pack builders and battery technicians were able to put together six cell packs with voltages approaching 7.4 Volts, to give those that could afford them, an edge over the rest.

   Ni-Mh (Nickel Metal Hydride) Batteries came along in the late 1990s, and by the year 2000 were available at ratings up to 3000Mah. Again, matchers and pack builders worked hard to provide the ardent racer with packs to provide that little bit of extra power, and ESC manufacturers also chipped in with improved controllers to take full advantage of this new technology.

   Now the problem wasn't gearing the car to get to the end of the race using the available battery power, but to find the brushed motor that could handle gear setting that provided the speed and acceleration without the motor overheating and wearing the commutator too much so it needed a skim after every 2 runs. My favourite at that time was the 9 Double.

   More recently, Li-Po (Lithium-Polymer) Batteries have appeared on the scene, providing are a huge step forward in performance when compared with Ni-Cad and Ni-Mh batteries.

Efficient Soldering

   In the sport of Radio Controlled racing, there are a number of things you have to learn to get you up there with the best. One of the most difficult, for those with little practical skill, is the art of Soldering.

   For their 540 silver can motors, Tamiya provide two wires, typically green and yellow, soldered to the endbell, with two bullet connectors to plug into the speed controller. While this is fine for bashing around the back yard, as you advance to a higher level you will soon find just how inefficient this method is.

   Motor wires are best soldered directly to the ESC. That way no energy is lost through high current draw. Some of the top drivers at one time even used to solder their batteries directly to the ESC.