A mini 4WD is a miniature model within the mini scale of between 1/20 (1:20) to 1/48 (1:48) scale. Currently, in 2013, the term is popularized mostly by a 1/32 (1:32) scaled, AA battery powered plastic model race car without remote control. All four (4) wheels are direct-drive, thus "4WD" for 4-wheel drive, as opposed to "AWD" or All-wheel drive. Side rollers guide the vehicle against the vertical walls of the un-banked track for steering, providing very fast speeds up to 65 km/H (40 mph) on the track. In Japan, Mini 4WD is also known as mini yonku (ミニ四駆) in Japanese. Though mostly popular in Asia, they are sold in many countries as Japan, Philippines Indonesia, Malaysia, Italy, Taiwan, Hong Kong & the United States.
- 1 History
- 2 Generation I (Schaper)
- 3 Generation II (Tamiya)
- 4 Generation III (Tamiya)
- 5 Generation IV (Tamiya)
- 6 Generation V (Tamiya)
- 7 Generation VI (Tamiya)
- 8 Generation VII (Tamiya)
- 9 Generation VIII (Tamiya)
- 10 Mini 4WD Design
- 11 See also
- 12 References
- 13 External links
In 1982, Mini 4WD was produced by the Japanese company Tamiya as a powered variant of common plastic automobile model kits. Since then racing and tuning up mini 4WD cars have become a hobby for people across the world.
In 1989, Tamiya commissioned Shogakukan, a Japanese publishing company, to produce two anime TV series based on the Mini 4WD cars: Dash! Yonkuro by Zaurus Tokuda, Bakusō Kyōdai Let's & Go!!, Bakusou Kyoudai Let's & Go WGP in 1996, Bakusou Kyoudai Let's & Go MAX, and finally Let's & Go!! Tamiya, The Movie.
Beginning in 1997, Tamiya mini 4WD cars were sold in the United States. Headquartered in Irvine, California, Tamiya in the United States holds USA Mini 4WD Championships at Marukai Corporation U.S.A. in Gardena, California.
In 1999, Tamiya Japan temporarily suspended the Great Japan Cup world championships for Mini 4WD racers.
By the 2000s, at least twenty-eight (28) other companies had ventured into the Mini 4WD market, and famously included Tokyo Marui, Kyosho, Academy, Auldey Animation and Toys, Circuit no Ōkami, Aoshima Bunka Kyozai, Matchbox (brand), Revell, Hot Wheels, Tonka, Hasbro, and Bandai. Many of them introduced their own lines of mini cars, while some produce replicas of Tamiya cars.
Beginning again in 2006, Japan holds National Mini 4WD Championships in Spring, Summer and Autumn each year and by 2012 Mini 4WD is popular in more countries including Thailand, Singapore, South Korea, Canada, Germany, Russia, India and China.
Guinness Book of World Records now shows the longest mini 4wd track in the world was set in Japan in October 2010 at 523.61 meters which record was quickly broken in Thailand in March 2011 at 1,074.5 meters at the Central World Mall sponsored by Panasonic.
Generation I (Schaper)
Stomper 4x4s were first created on February 14, 1980 by Adolph Eddy Goldfarb and sold by Schaper Toys. These toys were battery-powered vehicles that ran on a single AA battery and featured four-wheel drive. They were driven by a single motor that turned both axles. Of the first vehicles were a Ford Truck and a Chevrolet Truck.
Generation II (Tamiya)
In 1982, Mini 4WD was produced by Tamiya. These toys were battery-powered vehicles that ran on a pair of AA battery and featured four-wheel drive. They were driven by a single motor that turned both axles. Of the first vehicles were a Ford Truck and a Chevrolet Truck.
Generation III (Tamiya)
Generation IV (Tamiya)
Generation V (Tamiya)
Generation VI (Tamiya)
Generation VII (Tamiya)
In 2005, Tamiya produced an PRO Mini 4WD series starting with Avante.
Generation VIII (Tamiya)
In 2012, Tamiya produced an Rev Mini 4WD series starting with Avante.
Mini 4WD Design
In a standard 4WD design, the separate four wheels are allowed to rotate at different speeds through the use of differentials. This is important for cornering to eliminate binding. In a Mini 4WD, this is not a standard design and is only achieved through optional one-way wheel sets. Thus, the standard Mini 4WD utilizes a direct drive to all 4 wheels even around corners. Chassis' are designed to hold the motor and batteries in differing arrangements. There are sideways motors positioned in the rear. There are sideways motors positions in the front. There are in-line motors positioned in the middle. Rear and Front position motor designs position batteries side by side in the front or rear of the motor placement. Middle position motor designs position the batteries straddling either side of the motor. Rear and front position motor designs utilize a propeller rod extending from the main motor gear box that drives both the front and rear axles. Middle position motor design powers both the front and back wheels through separate gear boxes eliminating the need for such a propeller rod.
Chassis' are designed with front bumpers, optional side and rear bumpers designed to hold guide rollers that interact with the track's 58mm high walls.
The body is designed from hard plastic or soft, transparent Polycarbonate, known by the trademarked names Lexan, for special or limited editions, which attaches with a catch-type lock at the back of the car, distinguishes one model from another.
There are three specifications that characterize all motors: RPM, torque, and power-consumption. RPM is the speed the motor provides, and the torque its strength. Higher the RPM means higher maximum speed ; Higher torque gives more acceleration and allows the car to better withstand the difficulties of climbing slope or running through turns.
Different types of gears have different ratios of rotation of the motor and the wheel, and they include "Super Speed" (3.5:1), "High Speed" (4:1), "Speed" (4.2:1), "Normal" (5:1), and "Special" (ratio varies but are usually 6.4:1). Higher the ratio, better the acceleration rate and torque; lower the ratio, better the maximum speed.
Tires and Wheels
It is recommended that, among the different wheels available, the compatible ones must maintain the same size as those from the assembly packet. Smaller the diameter, more stable it is, as the car's center of gravity is lowered. Although one can easily assume that a larger wheel suits a faster car the best, this is not at all the case. Large wheels are for cars with high gear ratio (i.e. "5:1") and weak motor; small wheels are for cars with low gear ratio and strong motor. Wider wheels allow for more stability but suffer from friction, and, thus, speed loss; thinner wheels are intended for speed, but the car could be susceptible to flipping off the track.
There are four types of different wheels: normal plastic, one-way, aluminum, and lock-nut. Normal plastic wheels are fine, but they are not adequate for really fast cars. They become loose after disconnecting them from the axle several times. Additionally, they create drag when the car going through turns as the axle locks the two wheels at same speed, since the outer wheel must cover more distance than the inner wheel (relatively to the turn of the course). One-way wheels allow either side to roll faster than the other when turning, and minimize the speed loss in turns. Aluminum wheels are very light, sturdy, and best for speed. Some aluminum wheels have preventive measures against loosening with the axle. However, lock-nut wheels are the best in preventing the cars from losing the wheels during a run.
There are four types of tires: rubber, sponge, reston, and semi-pneumatic. Rubber tires come as standard with the Mini 4WD, and, although it has good grip, it is heavy and is susceptible to slipping on wet surfaces. The alternate solution to the rubber tire are the reston or sponge tires, which are very light, have good grip, and are better suited for rainy days. Yet, these get dirty easily, and they tend to exhaust the motor.
Bumpers are usually found at the opposite ends of the mini 4WD. Upgrading the bumper becomes a necessity as the mini 4WD is modified to run faster than what the stock kit usually runs. The faster the car, the more the car needs down force to counter the decrease in stability. The stock chassis+bumper combination does have a tendency to bend, causing the rollers to run at angles and may make the mini 4WD fly off the course. Aluminum, fiberglass, or carbon fiber plates are usually installed as after-market upgrades to prevent this from occurring. Another possible upgrade are the screws that keep the rollers to the bumper. Tamiya offers stainless steel ones.
Most after-market upgrade plates are usually wider than the stock bumper, and they facilitate the installation of "side extension" plates that make the front profile of the mini 4WD even wider.
Roller and Race Categories
Roller is the wheel that rests on either end of the mini car's bumper and glides against the wall of the course. This allows the car to change direction and maintain stability. Conventional roller will do fine on a car with average speed, but, on a much faster car, aluminum or ball-bearing rollers must be purchased to acquire additional downforce and stability. These rollers do not tilt in angle as the conventional plastic rollers, and, therefore, have better chance in preventing the car from flinging off the course. Ball-bearing rollers have small metal balls around the internal ring, on which the roller spins, in order to minimize friction. Some rollers consist of two rollers on a pole -one at the base and other at the top-, so that they may offer the best stability. There are three types of roller arrangements. The first one is in which all rollers are same-sized, and this is for straight courses. The second arrangement, in which larger rollers are stationed in the front, is less stable when running through corners but minimizes speed losses; the third arrangement, in which smaller rollers are put in the front, is more stable when running through corners but the car is more susceptible to speed losses as it pushes into the wall.
3 types of racing categories for Mini 4WD are Techinal, Speed-Technical and Drag Racing.
- Bakusō Kyōdai Let's & Go!! Popular anime/manga based on Mini 4WD
- Racer Mini Yonku: Japan Cup - Famicom video game
- Record Breakers: World of Speed
- Wikipedia for Scale Models
- YouTube Video Info on Maximum Speed
- "ミニ四駆情報". Tamiya. Retrieved 2007-01-21.
- Current Google Trends for Mini 4WD
- Mini 4WD Extreme
- Historical Box Art Archives
- Mini 4WD History
- Mini 4WD Records
- Mini 4WD Extreme Info On Motors
- Mini 4WD Hobby Info On Gear
- Mini 4WD Extreme Info On Wheels
- Mini 4WD Hobby Info On Tires
- Mini 4WD Hobby Info On Rollers
- Mini 4WD product information (Japanese)
- Mini 4WD Online (Malolos, Philippines)
- Mini 4WD Online (Manila, Philippines)
- Mini 4WD Extreme
- The Biggest Mini 4WD Boxart Gallery
- MINI4WD.IT 3600 mini 4WD images, Granprix in Italy, special info and videos
- Bakusou Kyoudai Let's & Go fansite
- Team Storm Mini 4WD world
- HONG KONG MINI 4WD ASSOCIATION
- EMPRESS SPEEDWAY - Mini 4WD Speedway of Hong Kong
- Indonesia Mini4wd
- Vancouver Mini 4wd Club
- Tamiya USA Basic Knowledge about 4WD
- SG Mini 4WD Forum