Tamiya M4 Sherman 105mm Howitzer - 23617
(Radio Controlled Model Review)

  Released by Tamiya on March 1, 2005, the M4 Sherman 105mm Howitzer (# 23617) is the Factory Finished, Limited Edition, RTR version.

  A front-mounted double gearbox, with two electric motors, operate together or individually to produce forward/reverse running and pivot turning. Metal torsion bars and suspension arms combine with the wide tracks to smoothly absorb bumps and dips in the terrain and provide high manoeuvrability. In addition, realistic engine sounds accompany the tank as it starts up, drives and stops to idle. The main gun can be elevated, depressed and swung to the left and right.

  The M4 Sherman, officially Medium Tank, M4, was the most widely used medium tank by the United States and Western Allies in World War II. The M4 Sherman proved to be reliable, relatively cheap to produce and available in great numbers. Thousands were distributed through the Lend-Lease program to the British Commonwealth and Soviet Union. The tank was named by the British for the American Civil War General William Tecumseh Sherman.

  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

My First National

   When I first started in RC, way back in the late 1980s, I would turn up to the weekly club meeting, with my Tamiya Boomerang, Acoms transmitter, two sets of crystals, a couple of 7.2v batteries, a charger and a tool box with a wheel spanner and a few spares.
   It was three five minute qualifying rounds and a final, and every month we would have a trophy meeting. The trophies were donated by a two of the older semi professional guys who basically ran the club and over the years had collected what must have been hundreds of trophies and had no space for them anymore. The lure of a trophy always brought out the "not as enthusiastic types" and the small church function room was always packed on those nights.
   About a year in, my collection of B final trophies was beginning to clutter my room, and my dad bought me the new Tamiya Manta Ray. That was the big turning point in my RC career.
   From then on it was A finals all the way. Then one day in the summer of 1992 the club organisers (the semi pro guys) asked me if I would like to go to a BIG national meeting way down south in Malvern. I asked my dad and with a bit of prompting he said "why not".
   When we got to that meeting we found there were around a hundred competitors, with ten groups of ten. I was in group "H". a two of my friends went down with us and they were in group "I" so were on just before me.

Information and Advice

Electronic Speed Controllers

   ESC were originally developed to be used in conjunction with brushed 27T stock and modified motors in the late 1970s, early 1980s. Compared to modern day Controllers, they were Bulky and heavy, constructed using basic resistors, rheostats, capacitors and transistors, crammed together on a simple circuit board, to provide stepped but smooth acceleration when compared to the old mechanical, servo operated sweeper Speed Controllers. An Electronic Switch to change the direction of current flow was used on some of these early ESC to give reverse operation. Although they were a vast improvement on the old mechanical speedos of the time, they were expensive, jerky to control, and prone to burn out if not carefully looked after.

   As new technology became available, improvements were slowly made, and with the introduction of the new FET (Field Effect Transistors) and some basic mass produced silicon chips, ESC were made smaller and their reliability gradually improved.

   By the mid 1990s, "regenerative breaking" was developed. This meant that energy that would have been lost slowing down the car by effectively turning the motor into a generator, was harvested and put back into the battery. This of course was long before F1 had KERS (Kinetic Energy Recovery System) and adjustable anti lock breaking was introduced.