Expert Advice - Basics

Starting From The Beginning

So you get your first car. You open it up, put it together, and put on a Plasma Dash. You take it down to a nice looking track with a handsome bridge and a few jumps. You slip in a pair of Tamiya 1000 mAh Ni-Cd batteries. Now you turn on the switch, and let it run. Zoom! It runs for about two seconds, and after reaching its top speed, suddenly flies off a jump. Your car zooms across the air, and lands on the ground hard with a sickening CRACK! You go over to take a look. Your chassis has snapped in half and both your motor and batteries seems to be caught in a bit of smoke.

Why do you think something like that would happen. Is it because the car can't take the speed? Is it because your tires are made of rubber and not sponge? Nope, not at all. It's because you simply took a brand new car without adding any hop-up parts except for a fast motor. You just thought your car would be the best just because of the motor. Well, that's wrong. Putting together a high-quality Mini 4wd isn't that easy.

Then what is right? Consider this: In a car, you want the highest possible speed, the most effective way to run your car, and the power to stay on the track. Let's start talking about the speed factor.

Speed

For the top speed, you must first observe the track you will be running on. For a straight track, look for a motor with more RPM (revolutions per minute), and for a technical track, look for a motor with more torque. Or, you can even build your own motor. After getting an idea of your track and the right motor, it's time for the gears and wheels.

You should know that gears have different ratios, like 4:1, or 2.3:1. But what does that mean? The number on the left represents the number of times a motor rotates, and the number on the right represents the number of times the wheel rotates. A 3.5:1 gear ratio would mean that if the motor rotates 3.5 times, the wheel would rotate one time. It's really not complicated. But to put the motor, gears, and wheels together, well, it's a bit more difficult. For a motor with less torque, use a larger gear ratio (ex. 5:1) and large diameter wheels. For a motor with a lot of torque, use a smaller gear ratio (ex. 2.3:1) with small diameter wheels. If you get that right, then you're all set for top speed. Now let's talk about effectiveness.

Effectiveness

Top speed is great, but without an effective way to use that speed and power, top speed won't be the best anymore. Effectiveness relies on your rollers, the type of bumpers your using, the wheels, and even the design of the body of your car. For example, if you only have a bumper in the front and don't have a rear roller stay, your car won't be stable and will shake around as in runs, therefore slowing down your car. However adding a rear roller stay and a few good rollers will help keep your car running straight, and making full use of the speed from the motor.

Staying On The Track

The two points above are the main points. But with all that speed and effectiveness, your Mini 4wd might still fly. I bet you've seen a car doing great at first, but when it reaches a sharp turn or goes on a bridge, it suddenly flies off the track. A car that flies is a horrible sight, and preventing that takes some deep knowledge. The discussion of flying can be found on other pages of the Expert Advice category.

Those are the three factors that you must remember. But when you get a Mini 4wd, you don't need to consider any of the above yet. What you want are three things that go for any car: ball bearings, gold plated terminals, and hard shafts. You need ball bearings so that the shafts of your car can rotate more freely with less friction, therefore making it faster. Gold plated terminals are a must have because it conducts electricity better, so it makes your motor faster. When moving at high speeds, normal shafts might get bent and twist, changing its shape. Hard shafts are much stronger, so it's more dependable.

After adding those three things to your car, then you can think about those three factors. These are what I consider the basics. But that's only a tiny bit of knowlege, because Mini 4wd is much more complicated than that.