Yokomo Puchi Maru
Fully proportional, FM-equipped, and under 3 inches long!
Minis and micros are the latest rage in RC, and their popularity grows as the vehicles “shrink.” The latest entry is Yokomo’s ultra-small Puchi Maru– a 1/60-scale machine with all the control features of a “fullsize” 1/10-scale car. Other micros match its diminutive size, but they have only the simplest toggle controls. The Yokomo stands out: it has a full-size FM pistol-grip transmitter, and under the Honda Fit shell are cleverly packaged electronics and hardware that give it fully proportional control. Let’s see how Yokomo pulled off this feat of micro-engineering.
Puchi Maru Features
1 Geared transmission with differential. The rearwheel-drive Puchi Maru is driven by a 3-gear transmission. Incredibly, the drive train even features a gear differential for smooth handling. The pencil-eraser-size diff is permanently sealed in its plastic housing, and for such a tiny assembly, it operates surprisingly smoothly.
2 Micro-motor. The Maru’s motor is about the size of a receiver crystal, and it’s snap-fit into the gearbox assembly. A tiny plastic pinion-only as big as a diff ball-is pressed onto the motor’s output shaft.
3 Rack-and-pinion steering. This aims the front wheels. The motor, gears and electronic hardware you’d expect to find in a servo are instead cleverly integrated into the chassis, and instead of an output shaft, the gear train ends in a pinion that meshes with the steering rack. It’s interesting that the motor that operates the steering system is identical to the one that drives the car! Can you imaging installing a 540-powered servo in your 1/Ao-scale car?
4 Rigid chassis. Sorry; no room for suspension. Every millimeter of chassis space is devoted to electronics and the steering and drive systems. A battery compartment is nestled between the steering servo and rear bulkhead, and the receiver/speed control circuitry is mounted on top.
5 Battery. Two 120mAh NiMH batteries power the Puchi Maru and are permanently installed in the chassis. Each cell is comparable in size to three stacked watch batteries.
6 Integrated electronics. A circuit board integrates the receiver and speed control and is mounted on top of the chassis. The frequency is fixed on the receiver, but the car and radio are offered with a choice of six frequencies for side-by-side racing.
7 Hard body. The Maru’s shell is made of tough plastic and is fully detailed right down to the side view mirrors and clear headlights. The kit is offered in two versions: with a Honda Fit body (shown here) and a Toyota Vitz-both available in red and silver. And what, exactly, do “Fit” and “Vitz” mean? In Japan, they’re cars that resemble small minivans; their loyal fans customize them and hop them up to eke more power out of their motorcycle engines.
We Drive it
A CAR OF THIS SIZE runs best indoors on smooth floors and tables; our company conference table was perfect for it. I was surprised by how quickly the little Honda moved out and how easy it was to steer around the objects we put on the table to mark our improvised track. The fully proportional throttle and steering controls functioned flawlessly, but the range from tightest turn to widest turn and slowest speed to maximum speed isn’t as wide as you’re used to with 1/10- and 1/12-scale cars. The car will peel out if the throttle is pegged, but with smoother input, it will launch without any tire slip. It reached 3mph; this may not sound fast, but that’s 4.4 feet per second-quick for a car that’s just 3 inches long. The Maru will spin out if, at full speed, you input full right or full left, but it’s easy to recover by chopping the throttle. Did you expect such performance from such a tiny car?
To test the Puchi Maru on other types of surfaces, we went to our local Boston Billiards, which turned out to be a cool spot for our photo shoot. The PM ran fine on the baize billiard table; it seemed as quick as it had been on the office conference table. On textured linoleum, the ride was slower and “rumbly,” and on a short-pile rug, it ran as if it was running on grass. It ran much more slowly because of the friction and hung up on high spots. It doesn’t have much ground clearance, so flat, hard surfaces are best. If you are interested in running the PM on a more realistic-looking surface, Yokomo makes a roll-up-mat track with a road course printed on it.
When the Maru’s two tiny batteries finally dumped, it had run for slightly more than 5 1/2 minutes-not bad, especially when you consider that it takes only that long to recharge the batteries for its next run.
A HIGH-QUALITY 27MHz FM pistol-grip transmitter controls the Puchi Maru. Compared with regular radios, there’s one difference: this one has a built-in charger. A short wire connects the car to the transmitter for charging, and a switch on the radio toggles between the “on” and “charge” modes. In the charge mode, an LED built into the charger’s starter button lights up to indicate a proper connection; just push the button to start charging. The light blinks while the unit is charging and goes out when charging is complete. With alkaline batteries in the transmitter, it took about 8 minutes to fully charge the car.
The DT-1 is powered by the usual 8, AA cells and includes steering and throttle trims. The transmitter looks and feels as solid as any other full-size system, and it’s light years beyond the tiny toggle controllers of the non-proportional cars that are the same size as the Puchi Maru’s. The grip and steering wheel are comfortable, and the construction feels solid.
Yokomo is clearly taking the micro-market in a new direction with the Puchi Maru; it brings full-size FM radio technology and fully proportional control to ultra-micro RC. This category has, up to now, been defined by more toy-like, non-proportional designs with simplistic controllers. Six frequencies make 6-car races possible, and there are sure to be races whenever two or more Puchi Marus are in the same room, but the tiny car also has plenty of solo appeal. Fully proportional control makes it easier (and more fun) to navigate around the house, and since the Puchi Maru drives just like a “big” car, you might actually be gaining valuable practice time when you think you’re just having fun. Much more than a novelty, Yokomo’s ultra-micro is real RC-only smaller.
YOKOMO USA (949) 252-8663; yokomousa.com
Copyright Air Age Publishing Oct 2002
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