I covered the steering lever ratio in my last write up. If you missed it, I recommend reading that first.
https://ameblo.jp/marcus38060/entry-12364848212.html
Personally, I feel that the steering lever ratio is 'more' important than the gyro setup itself, as gyro setup is actually very simple...but it’s the chassis setup (front alignment and steering lever ratio) that effects the performance of the gyro and the overall chassis.
WHAT IS A GYRO?
Gyro was introduced to RWD RC Drift to simulate the 'self steer'. This was not needed in AWD or CS as you have the front tires pulling the chassis in the direction you want to go.
In a 1/1 car, when the rear end of the car starts to slide, the steering will self steer as the front tires will try to find the 'least' resistance to keep rolling. Driver will counter steer to control the direction and angle of the drift. In 1/10 RWD drifting, gyro will simulate the initial self steering, then you would take over to counter steer to control the chassis.
WHAT IS GAIN?
Gain is like the 'volume' you adjust on the gyro to adjust the 'sensitivity' of the gyro. Many people interpret this as how much it counter steers, but that is not correct. Also many people think running lower gain is considered 'cool', but that is just preference. The higher you are able to set you gain without the 'wobble', the chassis is stable and tuned right. If you are not able to run the chassis with higher than gain 80, then you should look closely at the alignment, steering lever ratio and gyro placement. Many people in Japan run higher gain, there was a statistic by RC World magazine that more than 80% of the people run 60 or higher gain, with 15% running 100 gain. All my chassis can run with gain 80 or 90, or one of my chassis can run 100, then will tone it down to my liking. Having the capability to set it high, will always be an advantage if you go to a new track where it may be more slippery than what you are used to.
HOW DO YOU ADJUST GAIN?
Most gyro will have a small gain volume on the gyro itself. It can be adjusted on the gyro itself, but very difficult to make fine adjustments. I would strongly recommend to use the 3rd or 4th channel of the radio and adjust the gain remotely. This should be in the manual of the gyro or the radio, but typically there will be a gain lead from the gyro to simply connect into the 3rd or 4th channel of the receiver, and you will need to set the respective channel to control the gain.
WHAT IS THE IDEAL PLACMENT?
This is one of the frequent asked questions. This all depends on your chassis and chassis layout and what space is available. Ideal position is center of the chassis, placed on the main plate. I do see many people placing it on top of something, whether it’s the upper deck, on the servo etc...if it works, that's fine, but the best place is to find some space on the main plate of the chassis, use a strong double sided tape with some padding and place it firmly.
Gyro defaults itself at power on, and senses the angle of the chassis, but will also pickup any vibration and 'think' that the vibration is also part of the chassis angle and may try to correct the steering angle. Gyro being too close the drives, that create vibration, or mounted on something loose will have the risk of picking up the wrong signals. There are gyro gels out there, but I have not had the need to use it, even when the gyro is placed right next to the motor or the drive shaft.
Front or back of the chassis is a preference. Placing it on the bumper or the diffuser is probably an extreme example...but anywhere between the FR suspension block and the RF suspension block, is probably okay... I try to place it between the middle of the chassis and RF suspension block, not touching anything around it, and try to make the cables not affect the gyro.
This one is unique placement, a Sanwa gyro inside the Exceed aluminum case, placed under the battery. By raising the battery plate by 10mm, gyro, Yokomo WIFI unit and other cabling can be hidden under the battery, plus the main advantage is the gyro placement being on exact center of the chassis.
WHICH GYRO SHOULD I GET?
There are many gyros out in the market. Some for USD20, some for over USD100.
Some have more features to be able to 'tune' how the gyro reacts, and some have end point adjustability. If you are in it for the long run, try to find a major brand, and don't go too cheap, you get what you paid for, and you don't want to have to go out and buy another one. Some of the basic gyros look alike, and many people say they are all the same...they may be, but certain brands take more time in developing the software on how naturally the gyro reacts and to add more tunable features. So, the box may look alike or even be identical, but the software is different. Or at least I would like to believe they are.
Some known gyros with basic features are Onisiki, Yokomo YG and D-Like. These all look alike and are one of the most popular gyros.
Gyros with end point adjustment are Sanwa, Overdose (Ko-Propo) DAIS, the new Yokomo RPG.
Some higher end gyros will have custom or tunable capability. Overdose (Ko-Propo) DAIS, Futaba GYD, MST is a great example of higher end tunable gyros, but they will be more $$$. These will enable to change the 'line' of how the chassis will drive through the turns, adjusting responsiveness with transition, and/or how shallow/deep you want the chassis to run through the turns. Sanwa and Overdose (Ko-Propo) has priority settings to balance the gyro input and the steering input so you have better control after the gyro kicks in.
My best pick would be the D-Like. I have not owned the Onisiki, but many people have good reviews. Yokomo is also a good reliable gyro. If you are looking for something more, Overdose DAIS is great, but will require some learning curve to dial it in.
ANY OTHER TRICKS?
One thing many people don't realize, is that gyro has no idea where the servo is, which means that gyro has no idea where the end point of the servo or the steering is either. This is why I wrote the steering lever ratio write up before writing about the gyro.
If you are using low steering EPA from the radio and the chassis is about to spin out, the gyro can actually over correct beyond the radio EPA, as the gyro is connected beyond the receiver. This can potentially damage the servo as it may try to push the steering beyond a steering stopper and generate stress load to the servo. Servo connected to a gyro is already sensing more load due to the constant signals from the gyro. This is why setting the mechanical lever ratio closer to EPA 100 is important. However, if you own a gyro with EPA adjustability, then you do not need to be concerned. If your steering EPA is low and can’t set it higher, there is a technique to lower the EPA on the gyro channel soften the gyro, this may not make sense but it does seem to make the gain look more relative.
Also as noted in the steering lever ratio write up, if a small movement of servo makes the steering move a large amount, ie long servo horn, will makes the overall steering feel 'quick'. Any signal from the gyro will also make the steering very quick, which results in a very glitchy feel. Gyro has no idea about the steering lever ratio, so it may over correct, and try to correct it back again. This is why the steering lever ratio is 'key' in adjusting how the gyro feels overall. In other words, by utilizing the steering lever ratio, you can actually change the feel of the gyro as well.
Happy drifting!
April 7, 2018 / Charlotte NC
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