CARS - Operating Instructions for Rolling Chassis cars and Assembled Transmitter.

How a car is built.

  • Initially cars are available only in “rolling chassis” form, i.e. cars are assembled in the factory, the radio fitted and road tested. Customers can then trim, fit and paint the bodyshell and fit the front bumper.
    We include here some information on how the “rolling chassis” cars are assembled . This is intended largely to give owners a better appreciation of the design.

Battery holding magnets.

  • These are a firm press fit into the chassis and should protrude slightly both inside and outside the housing to ensure good contact with the battery and wire terminals. Take care to keep the magnet faces clean as these are electrical contacts.

Guiding arm.

  • A 4mm diam. x 3 magnet is press fitted to the leading boss and an M2 x 16 stainless screw is screwed from underneath and secured with a 2mm stainless nut (all screws need to be stainless or they may affect the steering magnets) and a 2mm nyloc nut retains it in the car. Steering plate Two 5mm x 3 magnets are fixed in place with 2 part epoxy. One must be north pole facing and the other south.

Front axle beam assembly.

  • Two M2 x 14 stainless screws are fitted through holes in chassis and secured with M2 nuts. (M2 spanners are difficult to obtain but pointed nose pliers will do the job)
    Position the lower suspension plate over the screws, position the steering plate moulding on the chassis, locate the LH and RH stub axle carrier mouldings over the pins on the ends of the steering plate and at the same time locate the king pins into the holes in the lower beam, position the upper beam plate and fix with two M2 nuts. The stub axle mouldings and the steering plate should move freely. (See photo in 'set up')

Wheels and axles.

  • Rear wheels and the drive gear are a press fit to the 2.0mm rear axle. To remove, hold the gear and adjacent wheel in one hand and twist the other wheel off. When refitting, replace the washers as supplied and ensure that there is a small amount of end float on the axle.
    Front wheels are free running on steel stub axle pins press fitted into the steering hub mouldings. The stub axles are a tight fit. It may be necessary to dismantle the hub to enable the pin to be pressed out. The wheel should have a little end float to ensure that it runs freely.

Radio receiver and steering coil.

  • The receiver board is held in place with one No.1 self tap screw and the coil with one No. 2 screw. The coil wires are, by necessity, very thin and great care should be taken if working in this area.

Motor.

  • The motor pinion gear is a press fit to the shaft and can be prized off by twisting a sharp knife under it. We find it easier to solder the wires to the motor terminals first and then fix the motor to the chassis with a little epoxy. Fit a battery and test the motor direction before fixing.
    The packer supplied is glued to the rear of the battery box and should provide the correct gear mesh. Motor and wheels should run freely and quietly. Motors can be easily removed by using a thin knife blade underneath.

Transmitter.

  • The pistol type transmitter can be easily opened and it's design is simple. A diode is fitted to save damage from an incorrectly fitted battery. The trigger is a press fit to the potentiometer shaft and should slide easily between the supporting sides of the casing when operated.
    Reverse is enabled by pushing the trigger forward. Driving in reverse needs practice but it enables cars to be driven back onto the track after a crash without the need for a track marshal. This enables much more realistic and skillful racing. There is no switch so the battery should be removed when racing has finished to avoid running it flat.

Battery and charger info.

  • Currently Magracing are not supplying batteries or chargers and so most customers first act will be to order these. We say “order” because the AAA size 3.8 volt lithium ion cells, whilst growing in popularity, will probably not be available from your local dealer but are easily and cheaply available on the internet. You will need a minimum of two cells, one for the car, one for the transmitter, and a charger. The cells are more usually described as 10440 size. These cells are available as protected and unprotected. Protection refers to protection against overcharging but we have found these troublesome and, as a good charger has the same protection circuits built in, we use unprotected cells. Protected cells are longer and may fit into the car but not into the transmitter nor into some chargers.
    The charger shown has worked perfectly for 4 years and consequently we have never needed to try any other although undoubtedly there are other equally good ones available. The one shown is an Ultrafire WF-138B and a quick Google at the time of writing shows availability from Dino Direct for 6.98 (about $11) post free. It charges 2 cells at once (a recommended feature when several drivers are racing) in approx. 30 minutes. Three different brands of battery are shown but all that we have used have worked well. A pack of 4 Trustfire 10440 600mAh rechargeable lithium ion cells is available from Ali Express for $1.67 per cell, post free. Even better prices may be available if you spend more time looking. We would not worry about the quoted cell capacity as this is not too reliable and all cells we have used give ample running time. You will note that insulation has been removed from the negative ends of the batteries. This is because, in the cars, the negative contact is made with the side of the cell. This ensures that, if the cells are inserted the wrong way round, the current will not flow the wrong way and damage the receiver. Cut around the battery with a sharp knife approx.12mm from the negative end and strip off the insulation. In the transmitter, safety is achieved by use of a diode in the circuit. If, on any occasion, your car does not work, the most likely cause is a battery inserted the wrong way round! The car and Tx batteries can be removed very quickly with a magnet tool using the two extra magnets supplied. Batteries should not be left on charge unattended or overnight.

Battery remover

  • The magnets can be glued to a suitable piece of wood, mdf board etc., with epoxy adhesive.
    Glue one magnet first and let dry, then glue the other with a steel plate across the magnets, otherwise they will stick to each other! See Magracing's 4 second pit stop on 'Videos' for a demonstration of a quick battery change.
    Whilst waiting for your batteries and charger you can fit the bodyshell (or build your track!)

Bodyshell trimming and mounting.

  • Tools required will include a pair of cheap curved nail scissors, a small half round file and some fine emery paper. The bodyshell as supplied will have already been trimmed around the base to the correct depth but the edges may need cleaning up. Cut out the wheel arches where marked with the curved scissors and finish with the half round file as photos. At this point you may like to locate photos of full size cars on internet, magazines, etc., which will be useful when fitting and painting the body.
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  • The bodyshell should be fitted (mounted) to the chassis and test run before painting. It is fitted using 6 magnets to effect a simple and very quick system with no screws to lose.
    Screw the 3 body mounting self tap screws fully into the holes in the car and then remove them. This will cut a thread and make adjustment easier later. Note; there is a choice of front mounting holes, for Ferrari and McLaren use the rear one and Porsche and Alfa the front.
    Hammer/screw the 3 self tap screws into a block of soft wood or foam plastic well apart and glue 3x 2mm diam. magnets to the tops of the screws with 2 part epoxy resin and leave to set overnight. Next day, screw these into the holes in the car chassis using pliers. Hold the heads of the screws carefully so as not to break off the magnets. If you fit the screws first before glueing the magnets on top, the magnets may be attracted to other magnets in the car and be difficult to hold in place whilst the glue sets. Position the other 3 magnets on top of these and trial fit the body and adjust for height. Roughen the inside of the body in the area of the mounts with emery paper. With the car on a flat baseboard, add a little epoxy glue to the tops of the magnets and to the inside of the shell, position the body carefully, add a little weight on top to keep it in place and leave to dry. Once dry, remove the body and the top 3 magnets should be stuck to the bodyshell. It is a good idea to then reinforce with more glue around the magnets in the body but take care not to get glue on the faces of the magnets.
    Check that the wheels turn freely when straight and on full steering lock. If necessary remove a little more plastic or adjust the body height.
    Drill holes if necessary for the roll over bars (except Ferrari) 1.4mm diam. Make wings, fins etc. as required and glue to body.

Painting

  • Before painting, wash the body thoroughly in warm water and detergent and dry well.
    Spray paint light colours first and mask over with tape and paint darker colours as required.
    Most aerosol sprays will be ok but NOT those for polycarbonate. Enamel sprays seem fine but will take longer to harden properly. Shape the roll bar with pliers and glue into place.
    Paint driver details with a fine brush. Spray paint the drivers helmet separately and glue in place along with roll bars etc
    The wheels can be painted using the masking card supplied. Cut a small hole in a sheet of paper and fit over the wheel to mask the chassis and use the card to mask the tyre as shown.

Front Bumper

  • The bumper should be profiled to fit inside the bodyshell with approx. 1.5 mm clearance. A piece of 2mm foam sheet should then be cut to the correct shape and glued onto the top surface . The foam should just clear the body otherwise it may affect the car handling.The bumper is fixed with two M2 screws and nuts.

Operating and racing your Magracer

  • Check that the settings for the Rx and Tx channel switches are the same. There are 16 possible settings as per the chart. The numbers relating to the settings are those which the lap counting system will allocate if you decide to buy one so it is logical to number your cars and transmitters to this system.
    To change the frequency, use a small pointed tool such as a nail file or similar.
    Batteries as received may or may not be charged. Give them a short charge checking that the green charger lights are flashing. Fit the charged batteries, the correct way round, and all should work. "Fully discharging lithium ion cells  may damage them so we recommend that they always be removed from the car/controller after use.   If a car runs hesitantly, either the car or the controller battery may be low on power".
    The receiver in the car has an auto cut out if the car is not run for 30 minutes. So, after racing, remove the battery from the car. Should you forget to do this, a capacitor in the rx board will be charged and the car will not work. To discharge the capacitor, remove the battery and short across the battery terminals for two seconds with a short length of wire as shown in the photo

Tyre Finishes

  • Your model car may be 1/32 of the size of a real car but it's weight is only a very small fraction of the real thing. This is one of the reasons why, the smaller the scale that model cars are made in, the lower the centrifugal force acting through the corners and the higher the cornering speeds. This is not necessarily a good thing if you are looking for realistic performance and challenging driving skills. Also small model race cars have virtually no air drag which is the main speed limiting factor with full size cars, After much testing MAGracing has achieved relatively scale acceleration, top speed and braking rates by careful choice of motor wind, gear ratio and low back emf to ensure that wheels do not lock under braking and thus drivers can drive much closer to the car in front without running into it. Drivers also have time to decide whether to take the racing line or, if another car is alongside, to stay in the outer lane. Reducing cornering speeds can only be achieved by use of low friction coefficient tyres. We eventually found that flexible nylon tyres were the best answer. These provide sufficient grip for skilled drivers but this can easily be increased for the benefit of novice drivers or perhaps those who prefer a little more grip. Our recommended tyre finish is, perhaps surprisingly, paper masking tape.  This gives an adequate increase in grip but still allows the rear end to slide.
    Wear rate is good and if anything grip increases as the paper wears through to
    the adhesive.    Masking tape is normally cream in colour but is best coloured
    black with a felt pen.   Black masking tape is available on the internet.
    Cut to approx. 3" (70mm) length and then into 1/8" (4mm) strips and wrap
    around the inner edges of the rear wheels.  Use a sharp knife to cut through
    the overlap to produce a butt joint (see photo)
    Grip can be further increased by the use of silicone gel, etc., but cars will then corner at full speed and all driving skill is then lost.

Guide magnet adjustment

  • The accuracy of track manufacture will undoubtedly vary slightly. Although the guide wire in your own track will no doubt be perfectly flush with the track surface!!, the same may not apply to other tracks you may visit.
    Therefore the height of the magnet is adjustable above the wire. If the magnet is too high, the car will turn off the track when the steering is applied. If the magnet is too low, it will catch on the track. Adjust with pliers until the magnet just clears the highest point of the wire.

Car set up and adjustment

  • The steering assembly must move as freely as possible. Hold the chassis on it's side and the steering plate with the two magnets should drop to the full lock position as shown. Turn the chassis on it's other side and the steering plate should drop fully the other way. This is essential for consistent lane changing. Also both front wheels must spin freely. The rear axle and motor should spin freely and there should be a small but discernible end float in the axle. A small application of oil to the axle and motor bearings and gears will ensure smooth and quiet running.
    Ensure that the bodyshell is not catching the wheels, especially on full steering lock. Trim off a little more or raise the mounting position slightly if necessary.

Steering coil adjustment

  • As supplied in the rolling chassis, the gap between the coil and the two magnets should be correct. The size of this gap affects the power of the steering coil. If, for instance, the track has a different gauge wire or the wire is not flush with the surface of the track, the shim packer could be changed. The coil fitted closer to the magnets will increase the power of the steering and vice versa. Any alteration to the body weight or tyre grip will affect the power required to steer. Note; as the battery power falls away, the strength of the steering coil will reduce slightly. If the car starts to miss some lane changes, it is probably an indication that the battery needs charging. Running completely flat is not good for the battery.

Driving your car

  • The transmitter must be held in the left hand and the steering wheel turned with the right hand.
    The wheel operates two micro switches and only finger tip pressure is needed when turning it.
    The principle of lane changing is that the steering must be activated i.e. the wheel turned, before the car reaches the lane change 
    point and held until after the car has passed this point.
    A useful feature is to paint arrows on the track showing where the lane change and racing line points are. Put the arrows just before the points. We use white arrows for the racing line and yellow arrows for lane change points which, as described, can sometimes be one and the same and therefore have two arrows.
    The steering uses battery power however so from a racing and battery endurance point of view, the less time the steering is applied the better. Also, the coil needs to cool between each turn otherwise it may loose some effectiveness. No permanent damage is possible, it's just good driving practice to centralise the steering wheel along the straights.

  • Radio Channel Frequency chart

    No1 No2 No3 No4 No5 No6 No7 No8 No9 No10 No11 No12 No13 No14 No15
    o
    o   
    o o
    o      
    o    o
    o o   
    o o o
    o         
    o o   
    o     o   
    o    o o
    o o      
    o o    o
    o o o   
    o o o o
    o o o   
    o o    o
    o o      
    o    o o
    o    o   
    o       o
    o         
    o o o
    o       o
    o    o
    o      
    o o
    o   
    o

    1 2 3 4
    1 2 3 4
    1 2 3 4
    1 2 3 4
    1 2 3 4
    1 2 3 4
    1 2 3 4
    1 2 3 4
    1 2 3 4
    1 2 3 4
    1 2 3 4
    1 2 3 4
    1 2 3 4
    1 2 3 4
    1 2 3 4
    • No 0 (Channel number)
      o o o o (Switch position)
      1 2 3 4 (Numbers on switches)
      Take care to ensure you are reading the switch the right way up, i.e. with the numbers 1234 along the bottom.

    Trouble Shooting

    • If the car is hesitant, the most likely problem is a poor power connection. Clean the battery, the connecting magnets and the wire connectors.
      Low Tx battery power will also produce hesitant running. For a car not working, check channel settings on Tx and car. Check that battery has not been left in the car for too long, i.e discharge the capacitor across the battery terminals.
      If the car wanders down the straight or turns off the track before the l/c point, the guide magnet is probably set too high.
      If the car rx. bleeps when the battery is inserted, remove the battery and replace and the car will then be ok.

      The car and controller radio program registers a new each time the battery is fitted. Occasionally this may not happen first time, or after a channel change. If the car does not run, remove and replace the batteries in the car/controller.


Latest Development

Magnetic Racing is currently developing a totally new chassis. We hope to have this released in the near future. Here are a few images of the progress so far.