Design and marking out
(Note dimensions quoted are usually in imperial
and metric. 2.54cms = 1”inch in case we forget!)
The Magracing system has been developed to enable more realistic and
skilful model car racing to take place in small indoor areas. To
appreciate it's great advances it it really necessary to have a
permanent or semi-permanent track at table top level. The scale of the
cars (1/32) is the same as slot racing and therefore tracks could be as
small as a simple oval on a 36” x 48” (915 x 1220mm) base but this size
would not use the potential of the system although would be useful for
testing. Acceleration and braking rates have been deliberately
restricted to nearer scale values for greater realism and to allow
greater driving skills to be incorporated and a main straight of around
108” (2.75m) is necessary to achieve anything nearing top speed.
(Remember, this is only the equivalent of 96 yds (90m) on a full size
track!) Also it is good to have alternating right and left turns with
racing line lane changes to test driver skills and reactions.
Magracing tracks can vary from a small home test track to a large track suitable for serious group or club racing.
Photo right shows an early large track. Soon afterwards, reductions in
guide wire diameter and improved lane change design meant the track was
dismantled. In view of such developments, later tracks were somewhat
smaller! Now that design has stabilised, we would happily build another
track of this size.
Space available is obviously a major criterion in track design.
Whatever the space available, it is desirable to fit in as much track
length as possible and, if there is space, include testing driving
features such as racing line routes, quick left and right bends,
gradients, bridges, etc.. The inclusion of a fly- over bridge does save
a little space as you are getting two sections of track in one area and
also provides an equal number of right and left hand turns, corners or
bends. Having said this however, the ability of drivers to be able to
drive back onto the track is greatly helped by having more run off area
alongside the track so it is perhaps a compromise between getting as
much track into the available area and at the same time having run off
space outside and inside the track. Scenery, trees etc., look great but
do also restrict the ability to drive back onto the track. Cars are
less likely to spin and block the track than slot racing and more
likely to over-steer off the track and it is helpful if there is space
on the outside of the turns so that errant cars clear the track and do
not block following drivers.
Many people have the idea of
reproducing a full size track in miniature but frankly this is not
sensible for most home or club situations. It is more important to
design the track to maximise the space available and to include a
variety of features. What can be done is to copy certain features from
full size tracks, the Karussel hairpin at the Nurburgring for example.
Whilst Magracing drivers can drive from anywhere around a track, we
recommend that, for serious racing, the track should be designed with a
view to drivers standing side by side along one side of the track as
has traditionally been the case with both slot racing and R/C racing.
Fly over bridges will inevitably block some driver vision but the track
can be designed to reduce this by perhaps raising the level on the far
side away from the drivers. This is always a good feature and is
particularly helpful vision wise to smaller, younger drivers. A slight
camber slope along the far track down towards the drivers will also
help with vision.
The logical start for a track design is a main straight (all tracks
need at least one long straight) with the drivers in front of it. A pit
lane along this straight on the outside of the track is also helpful to
allow drivers to put down or pick up cars and then drive onto the track
when it is clear, as full size practice. A shelf in front of the pit
lane is also a nice feature for drivers to put down their transmitters
whilst changing batteries for a pit stop! Unfortunately the AAA
lithium-ions we are using will run for up to 30mins so pit stops are
not needed very often. However, as the hobby grows, we will see
endurance races and pit stops will then be a necessity.
From the driver rostrum, the best vision is in a semi circle but most
tracks will probably be rectangular. A number of suggestions are shown.
Tracks should be edged with a barrier to stop cars leaving the track
but this does not need to be very high. 3/4” (20mm) is adequate. We use
cut strips of 1/8” (3mm) hardboard pinned to the sides of the
Lane changes (l/cs)
All lane changes must be designed to offer 'straight on' as the default
(do nothing) option. Turning the steering wheel, if turned the correct
way!, will result in a change of direction. If the steering is turned
the wrong way, Magracing's patented lane change plate will hold the car
on the default straight on route. (Without this plate, cars turned the
wrong way will leave the track and crash!)
Most tracks will contain a combination of racing line l/cs and lane change l/cs and these can often be combined.
The diagram LC2 shows the layout for an S type combination of right and
left turns where the racing line also involves a change from one side
of the track to the other. This situation is challenging for the
drivers and something similar is recommended for all tracks.
How many lane changes?
Whilst lane change points are easy and cheap to install, it is not
necessary to have lots of them. Better to start with a few, say 4, and
install extra later if it is felt that it would improve overtaking
options. In practice, most overtaking comes from pressuring the car in
front to make a mistake, much like full size racing!
currently have 2 tracks, Linford 4 and Linford 5 and statistically
these are 65 feet (21m) length with 7 racing line options and 6 lane
change options and 70 feet with 9 racing line options and 5 lane
changes. Some are combined racing line and lane changes. With lap times
on Linford 2 of around 12 secs, drivers have potentially up to 14
steering decisions to make every 12 secs in addition to speed control,
which of course varies on each turn depending on which lane the car is
in, and also decisions relating to other cars. So even a very
experienced driver will need time to learn a new track. Lane change
points are normally marked with arrows because, of course, it is not
possible to see them. We use white arrows for racing line l/cs and
yellow for lane changes and two arrows when these are combined.
Position the arrows a few inches before the l/cs.
Flyover bridges, when combined with figure 8 track layouts have the
advantage of producing an equal number of left and right turns,
increase the track length slightly for a given space and provide a
reason for inclines and declines. They do need a little more
woodworking skill however to produce the track base.
Gradients and hills;
These are no problem and add interest to any track. We have not so far
had a problem with camber change or twist in the track which can occur
when combining a climb with a turn but excessive twist could perhaps
tend to lift the magnet and reduce steering grip.
T1 track plan shows a small track on base 34” x 124” with RH and LH
lane changes which can be laid out on one sheet of 12mm (1/2”)
chipboard cut to three panels, 2 off 48” x 34” and 1 off 28” x 34”
test/race track on larger base 130” x 39”or larger incorporating right
and left 'S' turn with combined racing line and lane changes. Paint the
board with white emulsion and any mistakes can easily be painted out
and re-drawn. Start with the main straight, draw in the turns and
connect the short straights last. If the track width varies slightly,
it doesn't matter, i.e. at the exit to a turn, real cars will have two
wheels on the grass. You can easily re-create this if you wish by
pushing out the racing line (and the outer lane) further but still
painting the track the same width or you can have cars clipping a
chicane as photos.
Laying out the T2 track is complicated slightly by the fact that the
end turns are not 180 degrees and therefore the fulcrum points are not
in a straight line so a little trial and error is required.
Re. minimum radii, we suggest around 9” (22cms)
During 4 years of development,
several systems of track design and construction have been tried and
new ideas are still evolving. At present the simple system of marking
out on a flat base, fixing the wire down with adhesive and raising the
track level flush with cardboard or plaster offers maximum flexibility
allied to ease of construction and low cost. We have found it difficult
to rout slots to a consistent depth, especially over hills and dips in
the track. Any radius curve can easily be achieved simply by flexing
the wire. Spring steel wire, commonly known as piano or music wire, can
be purchased in straight lengths and flexed to produce perfect curves
and, if necessary for track modifications, can be lifted, cleaned and
reused . Also, and very importantly, it does not easily kink and
therefore can be stuck tightly to the baseboard . This is very
important as the car magnet runs very closely to the track/wire and any
bumps in the wire will allow the magnet to touch the wire and slow the
car. 0.7mm (22swg) piano wire is the recommended thickness with 600/700
micron board used to level up.
Once the table height base has been installed, track construction is
basically straightforward and requires little in the way of tools. It
does require a degree of care however if cars are to race and lane
change perfectly and it is probably a good idea to initially build a
small test track , built perhaps in two or three sections. When this is
working perfectly it could be extended. One of the advantages of the
track system is that it can easily and cheaply be altered and extended.
All of our own tracks have been so modified. If a curve radius proves
too tight, it can easily be cut out and re-routed, additional lane
changes can be added, etc..
Track frame construction
Pencil should mark out easily
onto the baseboard and errors can be rubbed out with sand paper if
necessary. A coat of white emulsion or similar paint will provide an
even better surface and mistakes can be painted over!
the main straight. If the baseboard has a straight edge, this can be
used as a guide. Having decided on the lane spacing ( 3.5” (89mm)
recommended) , mark out for the two lane wires. A metal straight edge
or 24/36” rule is useful here. Thes can be purchased quite cheaply
nowadays. Distance from the lane wire to the edge of the track we
suggest should be around 1.75” (43mm) but we usually decide this after
painting the track as you may wish to vary this (on the inside of turns
for example so that cars appear to run over the curb).
For marking out the curves (also known as bends or turns), a trammel is
necessary (see image) This can be made from a wooden lath of around
5/8” square. Drill one hole at one end a tight fit for a pencil.
Alternatively the pencil could be glued to the end. Measure along for
the various radii which will be required. Hammer through a slim nail or
panel pin approx. 1 ½ “ long at the selected radius.
We recommend that the outer radius of all turns where racing (fastest) line routes are used be
layed out to increase the spacing between the lanes to say, for a 180 degree turn, at least 5”.
This gives greater clearance between cars to allow for tail sliding and
also encourages drivers to take the racing line and penalises those who
do not. (When painting the track later, the standard overall width 7”
can be maintained and the offside wheels of cars on the outer lane will
then appear to run wide onto the grass.)
Racing lines can be installed on any curve of more than say 30 degrees
but remember that the cars must be able to approach the curve on the
outside lane. Also, drivers do need opportunities to overtake and
gentler curves are best left with the 31/2” spacing. The racing line
route can simply cut the corner and return to the outside lane or it
can change from say the left hand side through a right hand curve and
join the right hand lane so as to be on the outside ready for a left
hand curve (see LC2) This is effectively an S bend. It is necessary to
have a short straight between the LH and the RH curves to ensure that
the cars are running straight at the point of the second lane change as
a tail sliding car may not turn properly. Locate the position for the
trammel pivot pin and tap into the base board with a hammer to mark the
point. Also mark this point with a pencil X as other radii and
measurements may be taken from here.
Marking the first lane change and first turn
Having drawn the 2 main straights, mark out and draw the lanes exiting the turn.
Measure from the end of the baseboard for the outer turn (say 2.5”
minimum) and 5.375” further in for the inside lane (we usually allow
3/8”(9mm) between the inner and racing line wires)
Then set the trammel to the inner radius required and scribe the line.
The pin can be tweaked with pliers to adjust if necessary. Set to the
outer radius and scribe the outer lane lane. This same radius (for a
180 degree turn) can then be used to scribe the racing line. Make sure
it blends nicely with the straight at the lane change point. For turns
other than 180 degrees, most radii have to be determined by trial and
error. Position the trammel pin, tap with a hammer to mark the spot,
and mark out the racing line and the outer lane.
Marking out and fitting the lane changes accurately is most important if consistent lane changing is to be achieved.
Measure from the end of the baseboard to the racing line fulcrum point
and measure and mark this distance from the end of the baseboard at the
lane change point and mark a line square across as a base line for the
Measure and mark out lines at 5mm and 40mm as shown for the lane change plate position.
Continue to work your way round the track. Adjustments will probably be necessary for more complex tracks.
Laying the wires
We recommend 22swg (.028”,
0.7mm) piano (Music) wire. We can supply this, also the equivalent
thickness of card for building up the track level. As the flat l/c
plate thickness is dependent on the wire used and the lap counter plate
which fits into the track surface will be of similar thickness to the
wire, using different thickness's of wire could upset several other
Starting with the end of the straight and the first l/c,
cut the wire with side cutters or pliers to length from the base line
to the join in the board, apply a run of impact adhesive along the
line, lay the wire almost immediately, and, as it dries, check with a
rule for straightness and adjust as necessary. Wipe the ruler clean
immediately each time.
Next lay the default straight-on wire.It is important that this continues in a straight line from the incoming wire.
Apply glue to the short straight only and position and fix the wire checking with a ruler for straightness.
When glue has dried, curve the wire to the marked line and hold in
place with small panel pins as shown. More are needed towards the end
of the wire to maintain the curve. Lift the wire, apply some glue and
drop the wire back in place using weights if necessary to ensure the
wire sits down on the baseboard.
Next apply some glue to the flat l/c plate and position immediately.
Adjust carefully at an angle as shown and allow to dry.
To complete the lane change, pin and glue the alternative route wire
taking care to maintain the 2mm space between the wires. Use a 2mm
(.080”) drill or other gauge to check. Also ensure that the end of this
wire is level with the straight-on wire. If the wires are not level,
the guidance magnet will be attracted to the nearest one.
If you have ideas of modifying or extending your track in the future,
it may be a good idea to butt join the wires at the joints in the
baseboard. Otherwise it is not too difficult to cut the wire later if
necessary using a small circular carborundum saw in a pistol or dremel
drill. Ensure the joints line up exactly. Joints on a curve are a
little more difficult and the wire needs holding to the curve close to
the joint with extra panel pins until the adhesive has set.
You may wish to level this first section and l/c with card and test run with a car to check.
Levelling the track with card panels
The card used must be the same
thickness as the wire. 600 microns, also known as 360GSM, is just under
.028” but when painted is about right
sections can be easily marked out and cut to strips with scissors. Glue
to baseboard with suitable low cost impact adhesive or similar. Apply
glue to the card strips, position on baseboard to transfer the glue,
remove, wait a short time and bond in place. A small gap between the
card and the wire can easily be filled later with filler. Ensure that
the card is well stuck down. If a blister appears later, perhaps after
painting, cut it out with a sharp knife, add more glue and replace.
Curved sections are a little more difficult but pressing the card down
over the wire can mark it to aid cutting out. Again, the fit does not
have to be perfect, gaps can easily be filled later.
It is certainly a good idea to test run and prove the track before
filling and finishing just in case any alterations have to be made.
Plastering the track.
The quickest and cheapest way
to raise the track surface flush with the wire is undoubtedly with
plaster or similar powder filler. It is only the quickest way if you
know what you are doing however. If you have any plastering experience
or know anyone who has, then this is probably the way to go. Otherwise
using card panels is slower but much cleaner and simpler. Photos show a
track being plastered and test run. This track is similar to the T2
Finishing and painting
Gaps around the wire can be
filled with low cost white filler and sanded down. Take care not to
damage the card. After painting, the card surface will be much harder,
probably better to prime paint the surface first before any filling.
Any spare emulsion paint will do.
Also fill down from the card
edge to the base to enable cars to run on and off the track easily. We
suggest you leave filling around the lane change plates until the track
has been fully tested in case any alterations are necessary. Should the
card blister at any point, cut out the blister and re-stick down. Paint
a wide band of white emulsion around the outer and inner track edges.
Two coats may be necessary. Then measure from the guide wires and mark
the track boundaries with a pencil. The guide wires can be located with
a magnet if necessary. We obtain our grey track paint from our local
DIY store who will mix a small sample pot of emulsion very cheaply.