The Basics
So you've got your cars and your track, and you're all ready to race. Well go ahead and enjoy it.
But please bear in mind that slot cars, like real cars, are not something you can expect to just keep on working perfectly without a certain amount of maintenance and care.
Don't worry though, it's mostly fairly simple stuff, and there is a certain satisfaction to be gained from making sure that your stable of racing beasts is kept in tip top condition.
Terminology
Below you'll see the basic working anatomy of a slot car, showing most of the components we'll be discussing. These are the terms we'll be using throughout the rest of this manual.
Inspection
Inspection | Time: 5 mins | Rating: Essential | Skill Level: Low
The basics of a really quick, and simple inspection of cars to pick up on any problems. You should do this when you've bought a new car, as they don't all work perfectly straight out of the box. You should also repeat it regularly, whenever you're going to race. We won't be dealing with fixing problems here, so for the moment, just take note of any potential issues.
Wheels
Levels
To check that your wheels are level, put your car onto a flat level piece of track, with the guide in the slot. Check that the body looks more or less flat and level with the track. Then check that all four tyres touch the track. It's absolutely essential that both rear tyres have good contact with the track. If not you may have a problem with your chassis, or one of your axles.
Rotation
Pick up your car, turn it upside down, and turn the rear wheels. Both wheels should turn reasonably freely. If not you may have a problem with your gear mesh, or with the wheels rubbing on the body. Now turn the front wheels. Unless it's a four wheel drive car, these should spin with no resistance.
Tyres
Fit
Visually check that all four tyres fit their hubs properly. Then gently try to turn the left rear tyre in the opposite direction to the right rear to check for any tyre slippage.
Flashing
Visually inspect all tyres for any mold flashing, or other obvious faults, particularly on new cars. Flashing can be sanded off, but we'll deal with proper tyre truing later.
Guide
Rotation
Hold your car upside down, and turn the guide to the left and right. It should rotate easily, and equally to both sides, to an approximate angle of around 60° from the central position. When you let go of the guide it should preferably return to a central position.
Depth
Put your car on a spare piece of track, and position the guide right at the end of the slot. Lift the track to eye level, and check that the guide sits fully into the slot. If not you may have a set up problem , or more likely it's a problem with the braids.
Braids
Contact
Hold your car upside down, and check that the braids do not extend beyond the rear of the guide blade. If they do, snip them off with an old pair of scissors so that there is no chance of them touching and shorting the track.
Splay
The braids should have a slight splay at the end, with the weave picked apart into single strands. You can do this by picking at the last few millimetres with a screwdriver, or even your finger nail.
Angle
The braids should also sit reasonably flat against the base of the guide, apart from the last few millimetres which should be angled downwards slightly. These last two steps help to achieve maximum power pick up, whilst still allowing the guide blade to sit as fully into the slot as possible.
Braid Adjustment
Maintenance
The basics of a simple maintenance routine.
Tyres
Tyre Cleaning | Time: 1 min | Rating: Essential | Skill Level: None
Cleaning
Dirty rear tyres mean less grip, and less traction, so clean them regularly. You can press a damp cloth against one of the rear tyres whilst rotating the other. Or you can roll the tyres over the sticky side of masking tape, or similar sticky tape. Don't use gaffa, or duct tape as it's too sticky, and don't use cheap sellotape, as the glue can end up on your tyres.
Tyre Treatment | Time: 3 mins | Rating: Essential | Skill Level: None
Treatment
Rubber will harden over time, so treat the tyres regularly with 3 in 1 oil, WD40 or similar.
But oil's slippery, isn't it?
It may sound counter intuitive to put a lubricant onto the tyres, but the oil sinks in and revives the grip. Apply the oil to a cloth and wipe over the surface of the tyres. Allow the oil to sink in for a few minutes and wipe off any excess with a clean cloth, or kitchen roll.
Braids
Braid Maintenance | Time: 1 min | Rating: Essential | Skill Level: None
Maintenance
The braids will get dirty, and they might get a bit out of shape. To clean them, squirt a little lighter fluid onto the braids, and pull an old toothbrush over the braids from the front to the back. Obviously this should not be attempted anywhere near a naked flame. The cleaning process can help to tidy up the braids, but a little manual reshaping may also be necessary.
Braid Replacement | Time: 5 mins | Rating: Essential | Skill Level: Moderate
Replacement
At some point the braids will get worn, and straggly, and at this point it's time to replace them. Unfortunately, manufacturers often have their own way of fitting the braids; Scalextric have either pull out guides, or a plate that pushes out, Carrera have clip in braids, and others have the braids held in by ferrules on the motor wires. We're not going to go through each one separately, as they are all designed to be fairly simple, although they can be a little fiddly. There is a video below that goes through some of the systems.
Oiling
Oiling | Time: 3 mins | Rating: Essential | Skill Level: Fairly Easy
Lubrication for moving parts is obviously essential, but with slot cars you really only need the tiniest amount of oil. One small drop at each point is all that is necessary. You could attempt this with something like 3 in 1 oil or similar, but it makes more sense to buy one of the specialist products from a slot shop, as they should have a suitably fine applicator nozzle.
Bushings
Just squeeze one small drop of oil onto the points where the axles pass through the bushings. Turn the wheels manually to distribute.
Motor
Just squeeze one small drop of oil onto the points where the pinion shaft enters the motor. Turn the pinion by turning the rear wheels manually to distribute.
Magnets
Ahhh, the thorny old question of whether to use magnets...
Why?
Grip
Magnets, or traction magnets, are often fitted by manufacturers to the chassis of a slot car, so that it is pulled down towards the steel rails of most major track systems, to provide downforce, grip and traction.
Grip and traction are good, right?
Yes, usually. But in the case of magnetic downforce there are disadvantages, and the subject of traction magnets, or more specifically whether to use them or not, has been the subject of many heated debates and discussions amongst slot car enthusiasts the world over.
In spite of traction magnets allowing faster speeds around the corners, many racers actually open up their freshly purchased slot cars and pull out the magnet without a second thought.
So they want to go slower?
Not really, they just want a car that's more drivable.
Why Not?
Drivability
Magnets only produce an attraction when they are close to the rails, or at least the drop off is an inverse square rule, which means that a doubling of the distance from the rails will result in a quartering of the magnetic attraction. The end result of that behaviour is that a car with a strong magnet can end up being quite unforgiving to drive.
It only has two states. It's either glued to the track like a limpet, swishing round the corners at unbelievable speeds, or it's barrel rolling through the air at high velocity, whilst you wait for it's inevitable doom on encountering the next solid object on it's trajectory.
The transition between those two states is almost instant, and little or no warning is given of the impending change of fortune from victor to vanquished, and very likely broken.
Fun
Okay, but the alternative is lower performance?
Not necessarily, a mag free car can be tuned and fettled to have plenty of mechanical grip, good balance, and therefore good performance. But it provides it in a more manageable way that is often more fun to drive, because a car without a magnet will, like a real race car, tend to give some warning that it is approaching the limits of grip.
So, should I pull out all of the magnets?
The bottom line is that running slot cars without magnets is very popular, with many people swearing that it is the best way, and quite a few claiming it's the only way. It does require a different style of driving, and it also requires some tuning of the car, though some brands of cars are set up better to deal with non mag racing than others.
Of course if you want to race on a copper taped track you won't have a choice, because the magnets will have no effect. So if you ever plan to race at a club, it may be wise to at least check out mag free racing.
But there is no right or wrong way to race slot cars, it's a personal choice. The only way to make that choice is to try both options and decide for yourself.
Removal
Removing a magnet | Time: 1-10 mins | Rating: Your decision | Skill Level: Varies, dependent on car
Some manufacturers use an eminently sensible system for their magnets, where the magnet sits in it's own pod. This can be adjusted, without removing the body, to change the amount of magnetic downforce it produces. Or it can be removed completely in just a minute. If you haven't decided whether you want to race mag free, this system is an ideal way to test it out.
Other manufacturers make removing the magnet much more awkward, by requiring the body to be removed. Once inside you may be able to pull out the magnet with a small screwdriver, or push it from the underside if there's a gap in the chassis, or sometimes you may even need to carefully flex the chassis.
Find out more
Maintenance guide from Pendle Slot Racing
https://www.pendleslotracing.co.uk/blog/slot-car-maintenance/
Maintenance guide from Scalextric
https://www.scalextric.com/us-en/support/car-maintenance