Your RC cars do not go straight? Here is the solution.
First, make sure the geometry of your RC car is as straight as possible, and the steering rods must have equal lengths. Then,
follow these 5 steps presented here to solve the RC car steering problem.
1. Uninstall the servo horn first.
2. Turn on your transmitter and put the adjustment steering knob until the servo is centered.
3. While adjusting, make sure the wheel stays straight.
4. install the servo horn back to the servo.
5. Do a test run on your RC car. Make sure the ground is not too slippy.
If you still cannot make your RC car running straight, read the following information to examine your RC car in depth.
In-depth analysis of your RC car steering
Every RC car needs to run straight
In the first day when you receive your new RC car, you might want to drive it on a race track or bash around in its full speed. You probably want it run as fast as it can and be compatible with the other cars. However, you might notice some problem during speeding up of your car; it cannot run straight so that you are forced to slow it down so it is still controllable. It is no fun at all then.
You will notice this problem more often in RC (rock) racers instead of rock crawlers as rock crawlers are slow. As an RC (rock) racer goes faster, the straighter it needs to run. Without the ability to run straight, you will have a problem driving your car to complete at least one circuit.
For RC cars, after finishing a turn, both sides of the wheels must turn back to more or less 90-degree vertical positions (depends on whether it is toe out or toe in); while some minor deviation might be acceptable during bashing, it will become unstable in a race. Any RC crawler with a wrong move can fall from a deep slope and gets damaged in a race eventually.
Understanding the RC car steering system
In this post, I will talk about how to adjust your car once you notice the steering problem. Before we go into solving the steering problem, we should understand how the whole system works when you turn your car around a corner. The whole steering system has 3 identifiable parts which are the steering servo, the steering mechanism, and the wheels. Each of them contributes to the steering problem of your RC car.
Steps for solving the steering problem
Go to your servo first
To correct the steering problem, the first thing to check is your servo. First, make sure the servo is secured on the chassis, and its arm is installed according to manual. every car has its own correct way to install its servo’s arm. Otherwise, it will not work effectively. Also, you should turn the radio on and put the adjustment steering knob in the center before going further.
In addition, if you have installed a servo saver in your RC car, make sure it is built and installed correctly by reading the manual carefully as it can affect how the servo responds during steering too. For example, the link connecting the steering system must be installed in the top center of your servo’s arm if the servo’s arm has more than one hole on each row. If you do it, you will be able to make an adjustment on your car easily and accurately. Precision is everything in a race.
Get a quality servo
For servos, even you are in a budget, do not settle to low-quality servos as they tend not to have enough precision when they move left and right to control the steering mechanism. Usually, the higher the price you pay the less trouble you will have when you set up your system. Also, you need to make sure that your servo has enough power to move the steering system as the system does have some weight. For different road conditions, you should use a servo with different torque.
For example, for an RC rock racer/crawler, a servo with high torque is preferred. Futaba and Sanwa do produce some very high-quality servos with excellent precision. On some online stores, you pay about $40 for a Futaba S3305 (high torque with metal gears), and you have to pay a little bit higher for a similar servo produced by Sanwa. Other popular servos include Power HD R12 and Savox 1251MG and 1252MG.
Never and never settle for servos with plastic gears as plastic gears are too fragile. One hit on your RC car can ruin your happy day. This is my personal experience.
For RTR RC cars, you need to inspect the preinstalled servo to see if it meets the requirement mentioned above. Otherwise, you are advised to replace the preinstalled servo with a good quality one.
The RC car steering mechanism
The steering system is the part of an RC car that is responsible for controlling the direction of the wheels. As there are many moving parts in this system, the possibility of a mechanical error occurring is pretty high. If the areas that need to be tightened up are not set up tightly, or the areas that need free movement are not movable freely, then the wheels the steering system control will not turn back to the desired position.
To solve this problem, many hobbyists use spacers of different sizes to fill the gaps as necessary. You have to learn by experience on how to use these spacers.
Also, on both sides of the wheels, the lengths of the connecting links must be equal, or you will never drive your RC car straight even you have everything perfectly set up.
Finally, if you are planning to replace your plastic steering system with the aluminum one, read this post about how to customize your RC crawler.
The wheels-set the wheels toe-in
If you build the wheels yourself, you have to make sure that they can turn straightly at first. To help to achieve this result, you can use aluminum connectors instead of the stock ones. Aluminum connectors are stronger but they must not have much slack. Before inserting the connector for each of the wheels, you should use spacers to fill the gaps too. By doing so, your wheels should be able to run straightly.
Finally, try to set your front wheels to toe in (1-2 degrees), and rear wheels less toe-in, by setting up your wheels in this way, your RC car should run straighter. You can adjust the toe in/out the adjusting the connection links.
You might also want to consider getting a gyro that is a device used to hold an RC car in a straight line during forceful acceleration and braking or get bumped around by harsh road conditions.
Check out a Radio system with a gyro. It can be your last solution.
RC4GS is a radio system that comes with a receiver/gyro. I using it, and love it very much.
Check out an RC car control system with a receive/Gyro on eBay.
What can do after you try everything
After you try everything, but your RC car still cannot run straight, you will have a few more options.
- Sell it; you do not have enough skill to handle the problem of your car, so sell it and use the money to get another one. Tell the potential buyer the steering problem of your car. I will not buy a second-hand RC car online. Instead, I will go to a local hobby shop to see if there is any used one available. By doing so you can test it there before you pay the money.
- Run it anyway in the off-road conditions; while it is not as competitive, you will still have fun with it.
- Ask one of your RC car friends to tune it up for you. He might be more capable than you are.
To finish up this post, I would like to say that nothing is perfect especially when it comes to RC car adjustments. However, keep upgrading/adjusting/testing/racing your RC car are 4 important parts of the fun of this whole activity. What will you do to upgrade your RC cars? Hope you enjoy it.
Thanks for reading this post.
Written by Carlos Santos, your webmaster