Photos by Trevor Coult

I will explain in this article the technique I use to set my transmitter up to my car. I have refined this over the years, and if followed correctly it should mean you have a good starting point to work from. I always complete this procedure when I am setting up a new car, or if I have replaced the servo, and it’s also a good idea to check the settings from time to time, as crashes and general wear and tear can cause the settings to change. I will be using the KO Universe III transmitter for this demonstration, and the page numbers below refer to the KO instruction manual. Most high spec transmitters should have the necessary settings to achieve my explanation below, and I advise you to check out your transmitter’s manual if you are unsure how to find any of the settings I talk about in the article.

It’s important that before you start the set-up, you make sure your car is race ready. By this I mean that you should make sure you have the ride height set correctly for the tyres that are on the car, and you have the tweak set correctly. This is important, because if you have the front ride height incorrect, when you do adjust it to the right height, it will effect your front toe angle which will mess up the steering balance and having the tweak off will effect the turning circle that I will explain later.

1. The KO transmitter can either be run with all the settings available (Master) or you can choose custom settings, which means you can choose which settings you would like to be available on the transmitter. This is a useful option, as a lot of the settings won’t be of any use to most people (some are for gas cars, so won’t be of use to electric racers and vice versa), and having them in the menu means you have to scroll through loads of different choices to get to the ones you need. It is best to decide which options you are likely to use and set them onto the transmitter menu in one of the custom settings. This will cut down the time it takes to find the option you are looking for, which can be critical if you are doing it before the start of a race, when time can be tight! If you have chosen to use one of the custom settings on the transmitter p16 & p24, you must ensure that you have selected the following:

· model select p30
· sub trim p32
· steering curve p47
· steering balance p48
· steering travel p49
· memory reset p53
· servo reverse p56

You can choose which other settings you wish to use, but for this article these are the minimum requirement. If you are trying this for the first time, it’s a good idea to put all the settings to default, to make sure you don’t leave anything set incorrectly. You can use the Memory reset p53 on the KO transmitter to achieve this but make a note of any settings other than the ones used in this article, as these will also be reset, and you will have to put them back on if you wish to use them again.

2. To start with remove the servo saver from the servo. Now turn on your transmitter and car and fit the servo saver as close to vertical as possible. If the servo saver isn’t exactly in the centre then use the sub trim to adjust it until it’s correct.

You should only be about 15 either way of centre (the trim rate should be 10 as default p57). If it takes more, check you have the servo saver on the closest spline to the centre. You should always have your servo saver centred vertically, and adjust your steering arms to set your tracking straight. Make sure you don’t off-set the servo saver and have one steering arm longer than the other!

3. Now you should turn up the steering travel, normally to about 110%, this is to make sure you have enough lock on the servo to reach full travel on the car.

Go to the steering balance setting next. Turn the steering to the left, now you should increase the lock (it defaults to 70%) until you start to hear the servo start to buzz, now while still holding full lock on the transmitter, reduce the lock 1 or 2% until the servo stops buzzing. Repeat the procedure for the right hand side.

If you have the front end and the servo set properly, then your left and right lock should be close to each other. It’s not critical that they are the same, but shouldn’t be too far from each other, usually no more than about 10%.

Setting this up, means if you use maximum lock on your car during a race, you won’t stress the servo by forcing it past its maximum useable lock.

4. Now you should turn down the total lock on the transmitter using the ET-3 dial p49. I normally use about 65% lock on my car as a starting point, but some cars may have more lock than others, so you will have to set yours up to suit your car.

As a general rule you should be able to turn your car in about a 1 meter circle, but it will depend on your own driving style as to how much lock you will need.

5. You will now need to set the steering up on the track to complete the set-up. This procedure is known as the turning circle. There will nearly always be some slight discrepancy in the car set-up that causes the lock to be a little different left to right, despite having the servo set correctly. If you find there is a big difference in the turning circles (more than 300mm), then it may be worth checking the car over, as there might be something bent or out of line on the car.

First put the car down on the track, against a line. A tape joint is good to use if you are racing indoors. Now turn the steering to the right and push the car round 180 degrees. Next turn the car around 180 degrees and put it back down where it finished the first turn. Put left lock on, and push the car back towards the tape joint. If the car turns tighter than the tape, then reduce the left hand lock, if it turns wider, then reduce the lock to the right. Repeat the procedure, until the car turns the same both ways. It’s important to reduce the tighter turn otherwise you will spoil the servo’s maximum lock set-up you did earlier. Go through the turning circle procedure again, until the car ends up back against the tape joint you started from.

6. Next thing to set on the transmitter is the steering exponential (curve). This makes the servo move less around the neutral position. This helps make the car less nervous on small movements on the steering, which helps if you don’t have the car tracking perfectly straight, and also can help smooth out the steering. I tend to use about 15% negative exponential, but you will have to try it yourself to see what works best for you.

It’s not a good idea to go above 25% though, as once you get too much exponential on the car it starts to make the steering snatch. The servo won’t move much at all for a start but then it will suddenly move loads all at once, which will make the car hard to drive.

I don’t normally use any special settings on the throttle, but some drivers find that using a little negative exponential helps when using modified motors, as it makes the punch a little softer at the bottom end of the stick.

This procedure sounds difficult but once you get the hang of it, it should only take about 5 minutes to do the whole set-up from start to finish.

There are lots of other settings on the transmitter to fine tune it to your driving style, and I advise you to test them out, as that’s the only way you will know if they suit you or not.

Andy Griffiths