Marui Big Bear Datsun
Encyclopedia
The Marui Big Bear Datsun (MT-59-RC-4) was an early 1/12-scale electric "monster truck
" radio controlled car manufactured and distributed by Japanese hobby and airsoft
gun manufacturer Tokyo Marui
.
in 1984 as a kit without batteries, radio and charger, the Big Bear featured a plastic, tub-styled chassis, Mabuchi M480-RS motor, mechanical speed control and live axle
rear suspension as opposed to an independent setup. Tires were wide, chevron-treaded implement-styled units and actually comprised the majority of the Big Bear's suspension. The shock absorber
s were simple coilover
units which allowed for limited suspension travel. Coil spring
s also served to hold the front bumper in place and absorb impact. The body was a highly detailed styrene plastic Datsun
pickup with driver figure and "Big Bear" decal set.
Because of its low cost, ease of assembly and good factory and aftermarket
support, the Big Bear played an important role in the early growth of the radio control hobby. Due to intense competition from Tamiya and somewhat brittle plastic, Tokyo Marui pulled completely out of the hobby market by the end of the decade.
The 'Big Bear' was sold in Australia as a complete kit, including radio transmitter, batteries, and charger.
http://www.iconicrc.com/wp-content/uploads/2011/02/Big-Bear-524x427.jpg]]
Marui made a special replacement part "#048 - Strengthened Differential Gear Set" that consisted of a tri-bevel differential, larger 32 pitch gears, and a change to the gear ratios. This new differential gear set found its way into the re-release of the Big Bear (v.2) coupled with a new heat sink plate between the gearbox halves. There were some draw backs to the new gears; The added torque of the new gear ratios made the truck do wheelies more easily, and made the truck a little slower. In addition to replacement gears and heat sink, Marui replaced the original M480-RS motor with an RS540-SH motor, and a redesigned mechanical speed controller with covered contacts to eliminate contamination.
Monster truck
A monster truck is a pickup truck, typically styled after pickup trucks' bodies, modified or purposely built with extremely large wheels and suspension...
" radio controlled car manufactured and distributed by Japanese hobby and airsoft
Airsoft
Airsoft is a sport in which participants shoot round non-metallic pellets launched via replica firearms.Gameplay varies in style and composition but often range from short-term skirmishes, organized scenarios, military simulations, historical reenactments, to competition target shooting events...
gun manufacturer Tokyo Marui
Tokyo Marui
' is an airsoft gun manufacturer located in Adachi, Tokyo, Japan. Its main market is Japan, but third-party retailers sell in Hong Kong , Taiwan , South Korea, East Asia, and worldwide....
.
Background
Originally sold only through mail orderMail order
Mail order is a term which describes the buying of goods or services by mail delivery. The buyer places an order for the desired products with the merchant through some remote method such as through a telephone call or web site. Then, the products are delivered to the customer...
in 1984 as a kit without batteries, radio and charger, the Big Bear featured a plastic, tub-styled chassis, Mabuchi M480-RS motor, mechanical speed control and live axle
Live axle
A live axle, sometimes called a solid axle, is a type of beam axle suspension system that uses the driveshafts that transmit power to the wheels to connect the wheels laterally so that they move together as a unit....
rear suspension as opposed to an independent setup. Tires were wide, chevron-treaded implement-styled units and actually comprised the majority of the Big Bear's suspension. The shock absorber
Shock absorber
A shock absorber is a mechanical device designed to smooth out or damp shock impulse, and dissipate kinetic energy. It is a type of dashpot.-Nomenclature:...
s were simple coilover
Coilover
A coilover is an automobile suspension device. "Coilover" is short for "coil spring over strut". It consists of a shock absorber with a coil spring encircling it. The shock absorber and spring are assembled as a unit prior to installation, and are replaced as a unit when the shock absorber has...
units which allowed for limited suspension travel. Coil spring
Coil spring
A Coil spring, also known as a helical spring, is a mechanical device, which is typically used to store energy and subsequently release it, to absorb shock, or to maintain a force between contacting surfaces...
s also served to hold the front bumper in place and absorb impact. The body was a highly detailed styrene plastic Datsun
Datsun
Datsun was an automobile marque. The name was created in 1931 by the DAT Motorcar Co. for a new car model, spelling it as "Datson" to indicate its smaller size when compared to the existing, larger DAT car. Later, in 1933 after Nissan Motor Co., Ltd...
pickup with driver figure and "Big Bear" decal set.
Because of its low cost, ease of assembly and good factory and aftermarket
Aftermarket (automotive)
The automotive aftermarket is the secondary market of the automotive industry, concerned with the manufacturing, remanufacturing, distribution, retailing, and installation of all vehicle parts, chemicals, tools, equipment and accessories for light and heavy vehicles, after the sale of the...
support, the Big Bear played an important role in the early growth of the radio control hobby. Due to intense competition from Tamiya and somewhat brittle plastic, Tokyo Marui pulled completely out of the hobby market by the end of the decade.
The 'Big Bear' was sold in Australia as a complete kit, including radio transmitter, batteries, and charger.
http://www.iconicrc.com/wp-content/uploads/2011/02/Big-Bear-524x427.jpg]]
Kit Revisions
Owners of the original version (v.1) of the Big Bear experienced problems with its differential gears. This kit used the same gearboxes and gears as the Marui Jeep CJ (MT-59-RC-7) and the Marui Toyota Landcruiser (MT-59-RC-8) kits and consisted of 2 large bevel gears, and a gear set of 48 pitch metric. This proved to be a major problem for the first version of the Big Bear, as the special black M480RS motor and the large tires designed for the Big Bear created increased load, causing the differential gears to break or heat up and melt.Marui made a special replacement part "#048 - Strengthened Differential Gear Set" that consisted of a tri-bevel differential, larger 32 pitch gears, and a change to the gear ratios. This new differential gear set found its way into the re-release of the Big Bear (v.2) coupled with a new heat sink plate between the gearbox halves. There were some draw backs to the new gears; The added torque of the new gear ratios made the truck do wheelies more easily, and made the truck a little slower. In addition to replacement gears and heat sink, Marui replaced the original M480-RS motor with an RS540-SH motor, and a redesigned mechanical speed controller with covered contacts to eliminate contamination.
Specifications
- Scale: 1/12
- Chassis construction: ABS resin tub-style
- Transmission: Rear wheel drive with differential
- Suspension: Independent front trailing arm and live axleLive axleA live axle, sometimes called a solid axle, is a type of beam axle suspension system that uses the driveshafts that transmit power to the wheels to connect the wheels laterally so that they move together as a unit....
rear suspension - Shock absorbers: Simple coiloverCoiloverA coilover is an automobile suspension device. "Coilover" is short for "coil spring over strut". It consists of a shock absorber with a coil spring encircling it. The shock absorber and spring are assembled as a unit prior to installation, and are replaced as a unit when the shock absorber has...
- Motor: Mabuchi RS-540 (v.1) / RS-540SH (v.2)
- Tires: Semi-pneumatic rubber chevron
- Original Marui catalog number: MT-59-RC-4
Spare Parts List
The following Marui RC Parts were used for the Big Bear, as well as other Marui kits:| Part # | Description |
|---|---|
| #007 | GEAR & MOTOR CASE |
| #010 | OILLESS BEARING SET |
| #014 | CONTROLLER SET (the original speed controller for v.1) |
| #016 | CONNECTOR SET |
| #021 | SERVO SAVER SET |
| #028 | DIFFERENTIAL GEAR SET (the original gear set for v.1) |
| #029 | PINION SEAR SET |
| #030 | FRONT ARM SET |
| #031 | REAR ARM SET |
| #032 | REAR AXLE SET |
| #033 | BUSHING SET |
| #035 | FRONT TIRE & WHEEL SET |
| #036 | REAR TIRE & WHEEL SET |
| #037 | BUMPER SET |
| #038 | ADJUSTER |
| #047 | CONTROLLER SET (the new and improved speed controller for v.1) |
| #048 | STRENGTHENED DIFFERENTIAL GEAR SET (the new and improved gear set for v.2) |
| M060 | CHASSIS |
| M096 | WINDSHIELD-BB |
| M097 | ROLL BAR |
| M098 | SEAT-BB |
| M099 | BODY-BB |
| M132 | IDLER GEAR |
| M133 | BODY MOUNT |
Aftermarket Parts
Many supporting manufacturers developed products for the Big Bear. Here is a list of known aftermarket parts designed specifically for this kit:| Manufacturer | Part # | Description |
|---|---|---|
| BO-LINK | BODY MOUNTING KIT | |
| BO-LINK | FORD VAN BODY FOR BIG BEAR | |
| BRU-LINE | 4202 | SUPER SYSTEM REAR HUB - BIG BEAR |
| BRU-LINE | 5278 | BIG BEAR BODY MOUNTING KIT |
| IMEX | DAWG TIRES FOR BIG BEAR | |
| MOORE'S IDEAL PRODUCTS (MIP) | BBG HEAVY DUTY GEAR SET FOR BIG BEAR | |
| MOORE'S IDEAL PRODUCTS (MIP) | BIG BEAR BALL DIFFERENTIAL GEAR | |
| MOORE'S IDEAL PRODUCTS (MIP) | CASE SAVER | |
| MOORE'S IDEAL PRODUCTS (MIP) | IDLER SHAFT | |
| MOORE'S IDEAL PRODUCTS (MIP) | TEFLON AXLE BUSHINGS | |
| PRO-LINE | 2512 | CHROME HUBS (FRONT) |
| PRO-LINE | 2513 | CHROME HUBS (REAR) |
| RACE MASTER | 701 | BIG BEAR WHEELIE BAR |