Maintenance

So your driving is improving with every race. You are coming out of the slot less, you can deal with traffic better because you are driving your own car and not trying to race faster cars at their pace. Over the course of a race you can complete more laps than faster cars by driving at your pace and having fewer offs.

As you improve and you are driving with a higher level of consistency one of the main differences between you and the competition is your car. Prepare your car better than the others and you will significantly increase your chances of winning. If your car is not maintained or well prepared for a race, the chances are you may not even finish the race, never mind win it – believe me, there is nothing worse!!!

Carrying out the following basic maintenance and checks on a regular basis will not only make you car last longer (therefore saving you money) but will also make your car faster, handle better and therefore more likely to give you the chance to win.

Note:- The following is based on an "Introsport" Class where the motor is sealed – I have not mentioned the motor at all – when it slows noticeably or dies - change it!

Chassis

Assuming your car has been built properly in the first place, and is therefore straight and true when you get it, it’s your job to keep it that way. Each time you hit a barrier, another car or the floor, you run the risk of bending the chassis to some degree. The harder the hit the higher the chances of sustaining damage which will affect the car’s handling. If your car doesn’t feel the same after an accident, check the chassis as soon as possible:

Front impact can often damage the guide tab so that the guide is pointing downwards or upwards and this will badly affect the handling – it will easily come out on bends. The guide should be very slightly inclined upwards when looking from the side. This reduces friction and ensures that the back of the braid contacts the track rather than the front – so the braid wears from the rear. The incline has to allow for the incline of the chassis with tyres on and a tiny bit more. The guide can be bent to the correct angle by hand - take care to put even pressure on either side so keeping the guide level while bending.

The guide must be level when viewed from the front of the car. If not the handling will be affected. Again the guide can be twisted by hand.

Put the underside of the chassis (with the guide overhanging the edge and with the wheels removed) on a flat block and check that it is flat by pushing down on the outer corners of the pan. If you can push the pan down onto the block, the pan is twisted and needs to be straightened – let someone show you how to straighten it. If the centre section (with motor, axle bearings and guide) does not sit flat it needs to be straightened too.

Tyres

Your tyres have to be in good condition or your car will not handle properly. After each race, clean them with a rag dipped in lighter fuel. Wet the rag and run it across the tyre surface to remove track glue and dirt. Do not soak the tyre with lighter fuel as this will destroy the glue bonding the rubber to the hub.

After several races your tyres will be worn into a cone shape i.e. the outside of the tyre will be a smaller diameter than the inside. As this happens the car will become less stable. Assuming the tyre has enough rubber left, ask someone to true the tyres for you. This only takes a few minutes and will make a big difference to your car.

Always check your tyres for damage such as cuts and remove any loose pieces of rubber.

To avoid your tyres drying out and losing their grip it's best to remove them and store them in the fridge or freezer when you can.

Always check your car for ground clearance before each race. You need enough rubber to last the race otherwise the chassis will touch the track and the car will slide all over the place. Your car will also damage the track so you owe it your club or hosting club to maintain sufficient clearance. Make sure you have at least 0.5mm clearance although Introsports cars seem to run well with up to 1.5mm clearance. Remember tyre wear depends on the type of rubber and the track surface – over time you will get to know how long your tyres will last and which rubber suits which conditions

Guide / Braids

The guide is another important part of the car and should be regularly checked.

It is important that the guide centralises itself – this helps the marshal to replace your car quickly - and the lead wires play an important part here. They should have been routed to ensure that the guide centralises and it is important to check this action on a regular basis. Check that the lead wires cannot catch on the chassis as this could affect the guide action. Also, check that the lead wires cannot fall through the chassis as they will touch the track and make the car undriveable.

Check the guide for play - the guide should be free enough to rotate without sticking, but not too loose. Tighten the guide nut down (be very careful not to cross thread the nut and post) so that the guide cannot turn then back the nut off until the guide can just rotate freely and centralises itself. A drop of oil under the guide tab will help give a smooth action. If you cannot get the guide to rotate and centre freely, the chances are the guide tab is bent or the guide post is fouling in the guide tab hole – the guide may need to be replaced.

A common problem is a guide which sticks when it is turned against the chassis. This can happen in an accident and again makes it difficult to marshal as the guide has to be freed each time. You may have to trim a bit of the guide to prevent it fouling the chassis.

Check the lead wire connections onto the braid clips for broken strands. Any signs of wear and the wire needs to be changed (or cut and reconnected) as a break is probably not far away.

Your car has generally only three points of contact with the track – the two rear tyres and the guide / braids so the braids must be checked and maintained regularly to ensure a good electrical pickup and proper handling. They should sit very slightly inclined up with a slight spring towards the back – check this before each race and if they are out of line use your thumbs to sort them out. Keep the braids clean by soaking them in lighter fluid and wiping them dry - they should be bright and clean and not dull. After a few races the braids will become frayed, burnt and too dirty to clean – this is the time to change them.

Finally, if your car ends up on the floor after an accident the chances are your braids will be messed up – ask the marshal to check them and put them straight – if the car is still not right stop at the first opportunity and do it yourself.

Lubrication

Before each race lubricate the following points on your car:

With a point oiler – a couple of drops is plenty:

Rear axle bushings – particularly if using bronze bushings as these do not retain oil like oilites

Both motor bearings, particularly the can bearing which is under most loading

With a stickier, heavier lubricant:

Gears where they mesh together – running will spread out the oil. Try and keep the lubricant off the tyres

The golden rule of lubrication is a little and often.

Gears / Rear Axle

Regularly check your gears for the correct mesh. This is most important if your gears are set up using axle spacers - if you take the axle off and forget to put the spacers back the mesh will be wrong and your gear will not last long. Write down which spacers go where so you can rebuild the rear axle correctly each time.

All gears, even metal ones, should be quiet when correctly set up and lubricated. See how much play is in your gears when new and check for that before each race. If you can hear the gears become noisy during a race it will probably be too late – a sure sign that maintenance has been missed.

With metal gears, wear should be slow but once it starts gears can quickly deteriorate as wear accelerates. Wear can be taken up by adding spacers but this is delaying the inevitable and could result in a tooth being lost during a race. Better to regularly lubricate and check the mesh and gear condition. You can check tooth wear with a magnifying glass – you will see small notches appearing in the teeth which lead to a sloppy mesh.

If you are using plastic gears a good smooth mesh is vital. If there is too much play the gears can strip very easily during a race, particularly with higher performance cars.

The rear axle must be set up properly to reduce running friction and maintain the gear mesh when running. Do this as follows:

Put both wheels on the axle and tighten the wheel on the gear side fully. Do not tighten the other wheel but nip the grub screw lightly onto the axle. This wheel and the gear are now hard against the axle bushings. Holding the gear, slightly twist / rotate the loose wheel whilst pulling it gently away from the bushing. You are trying get side play which you can just feel but not see. When the play is just right tighten the wheel onto the axle. If you get too much first time repeat the process and try again. After a while you will be able to do this easily. Never run your car with too much side play as this will damage the gears very quickly. If in doubt ask someone to help you.

After an accident (when the back of the car hits a barrier side on) the rear wheel can be pushed along the axle which tightens the wheel against the bushing – if this happens your car will have poor acceleration, go slower and brake quicker. The motor will also be straining hard – be alert to this and correct immediately if you suspect this sort of damage.

If you have taken time to set up and regularly lubricate these parts they will last for a long time. When you can feel play in the rear axle bushings they should be replaced as this will mess up your gear mesh and affect the car’s handling.

Body Shell

The body shell is important for the aerodynamics of the car and from this point of view should be in good condition. Tape up splits and tears and keep the shell looking as good as you can.

Most importantly check the following on a regular basis:

Body mounting holes should not be damaged or close to ripping through the bottom edge of the shell. Losing a body mount during a race will lose you the race

Ensure that no part of the shell is touching the track i.e. along the front edge and along the sides, as this will seriously affect the car’s handling

General Cleaning

Every two or three races (ideally before every club night) take the rear wheels, gear and axle out, clean the parts, reassemble and relubricate. Take care to put the spacers back in the right place. If you have time, check out as many of the above points as possible including chassis and body shell – 5 minutes before a race is not the time to find out something is wrong. You should also clean the chassis to remove track rubber and dirt and any rust that may be starting.

Controller

It is very easy to neglect your controller only to find that this vital piece of equipment fails or plays up at a crucial time.

If you check the following (based on a trigger type controller) on a regular basis you will minimise the risk of your controller letting you down:

Lubricate the trigger bushing

Check the trigger post is tight

Clean and polish the wiper pad and button with metal cleaner

Check the condition of the +ve wire connected to the wiper button – this moves with the trigger and can fray

Check that the full power and full brake contacts are making properly. If the trigger pivot loosens the trigger stops can prevent these contacts from making resulting in no brakes and/or reduced power

Check the trigger return spring for a smooth action

Summary

In summary carry out the following routine maintenance before each race:

Clean tyres and check condition / remove loose rubber from cuts

Lubricate rear axle bushings

Lubricate both motor bushings

Lubricate spur gear / pinion

Clean and flatten / straighten braids

Check lead wire to guide connections for wear or damage

Check guide action and adjust guide nut / lubricate if necessary

Check that ground clearance at rear is adequate

After replacing components such as wheels, gears, braids, guide… check the following:

Gear mesh

Rear axle side play

Braid alignment

Guide action

If you suspect crash damage check the following:

Check the guide for level and bend back if necessary

Check the chassis for flatness and straighten where necessary

Check the body mounts for damage / wear and repair where necessary

Check the body for fouling on track and trim / adjust where necessary

Check rear axle for free rotation (the bearing supports could be bent). You should be able to spin an axle with gear freely in the bushings – if it stops spinning after one or two turns then it’s too tight

Check rear axle sideplay

Over time the above checks should become second nature and will take only a minute or two. As always you will learn only from bitter experience. With this advice your bad experiences should be minimised, as your car will be less likely to let you down.

Finally this is intended to be a "what to do" rather than a "how to do" guide. There are many different ways of achieving the same result so if you find a better way share the information with others – we are all learning!

Stuart Strachan

Copyright © 2002 British Slot Car Racing Association     All rights reserved

 No liability is accepted for this information or any use to which it may be put