Make your own slot car chassis with this simple design process
Abstract
There are many slot car body kits available today providing the slot
car enthusiast with many options to make their own functioning slot
car (Scalextric car). Some of the body kits are finely modeled while
some are more basic but all of them need a chassis in order to be completed
and run on the slot car track. This article explains the making of just
such a chassis.

Introduction
There are a myriad of small and large scale suppliers of 1:32 scale
slot car body kits out there all making resin based slot car kits, most
include the windows and the interior. The very best include all the
trim parts in metal too, laser cut this and metal cast that. So, the
whole range is out there somewhere. The problem has always been about
the modeling skills to assemble these kits and then to track down a
1:32 scale slot car chassis, wheels and tyres so you can race your wonderful
model. So here you are, all the information needed to make your own
slot car chassis.
Making the basic form
The important aspects of a slot car chassis are:
This was done simply to minimise design effort and to allow the slot
car modeler to use parts that are in plentiful supply. Therefore, someone
with an existing Scalextric car could use all the parts they had to
make the chassis functional. The next problem to overcome was the risk
of the rear axle coming lose from the chassis.
This chassis is to use plain holes for both the front and rear axles
to give the chassis good strength. Scalextric and other slot cars use
an open clip arrangement for the rear axle bearings which can "unclip"
in use. Scalextric get round this by adding extensions to the interior
of the car which hold the rear axle bearings into place.
With resin slot car kits these extensions are not present so the standard
Scalextric solution is not robust. As a result we took the solution
to use plain holes which cannot fail in this way. This was especially
important as we were adding a Neodymium magnet for magnatraction to
our slot car chassis.

The image above shows the basic form of the chassis taking place. We
started with the motor mounting and the related rear axle position.
Here you can see the start of the motor mounts the rear axle bearings
and the cut out for the contrate gear as well as the chassis side supports.

At his point we've added a little more detailing to the rear of the
slot car chassis and the motor fixing solution. We've added the basics
of the front end too. The guide blade mounting is in position as are
the front axle bearings. In this image you can also see the motor in
position and the body mounting solution is in place and being tuned.
This image shows the chassis with the first trail of the selected wheels
and tyres. In the first instance there will be two wheel options, one
road type and one Minilight type (the road wheel is on the rear and
the Minilight wheel is on the front). The wheels have the same form
factor and so can use the same range of Max Grip tyres. The picture
above shows the largest and smallest tyres suitable for these wheels.

This picture shows the chassis fully assembled and a little more refined.
The guide mount has been tidied up as has the side sections. You can
clearly see the motor is mounted at a slight downward angle too. This
allows the rear axle to be mounted lower which, in turn, allows smaller
diameter wheels and tyres to be used. The original concept was to allow
the Scalextric small Superslix wheels and tyres to be used if desired.

Above you can see the underside of the fully assembled chassis. This
image shows the motor and rear axle arrangement as well as the guide
and body fixing solution. This chassis will be secured to the slot car
body by means of 3 self taping screws, 2 at the rear and one at the
front. As this chassis is intended to run close to the track surface
the screw heads are sunk into the chassis surface.
Making the chassis adjustable
At this stage we have the basic form of the slot car chassis with a
fixed wheelbase of 75mm. This is of little use unless your slot car
body has the same wheelbase. So, there's only one solution, make the
slot car chassis wheelbase adjustable.

And now the scary bit. Clearly, all cars as well as their slot car
clones have different wheelbases. That's the distance between the front
and rear wheels. So, any universal slot car chassis must be adjustable
for wheelbase. This means cutting the chassis into two pieces and providing
a means to allow the wheelbase to be adjusted and set. This image shows
the front and rear chassis pieces as well as the start of the sliding
mechanism.

In order to manufacture this slot car chassis in volume we needed to
provide it with a consistent surface finish. Some parts were glossy
plasticard surface, some parts were superglue finish and much was a
sanded or filed finish. Also, there were minor surface imperfections
due to the amount of machining carried out to make these master parts.
To remove the minor surface imperfections we spray painted the slot
car chassis in primer and sanded it back. We repeated this process until
the surface imperfection were cleared away. Here you can see the two
master chassis pieces prepared and ready to the make the mould as well
as the master wheel models and the selected fixing screws, washers and
Nyloc nuts.
Into production
Making one chassis is good but the plan is to make lot's of chassis
kits for the slot car makers out there. Therefore, the master two slot
car chassis pieces have to be copied many times over. We use a low volume
moulding method make copies of the original parts to go into the slot
car chassis kits.

Above is the complete slot car chassis kit. This plastic moulded slot
car chassis kit is ideal for many of the 1:32 scale resin and plastic
slot car body kits available. The kit comes complete with:
- Rear chassis piece
- Front chassis piece
- 2 off stainless steel screws
- 2 off stainless steel plain washers
- 2 of stainless steel Nyloc nuts
- 2 off front axle spacers
- Neodymium magnet (optional)
Dimensions:
- Overall width 33mm
- Height (without motor, axle and guide) 12mm
- Overall length (minimum)
92mm
- Overall length (maximum) 112mm
- Minimum wheelbase 64mm
- Maximum wheelbase 84mm
- Recommended minimum tyre outside diameter
16mm (small superslix tyres)
This chassis is designed to use the following standard
Scalextric parts:
- Mabuchi S can motor
- Rear axle (black or yellow contrate gear) 3/32" diameter
- 9z motor pinion gear
- Front axle 3/32" diameter
- Guide blade, pins and wires
- Wheels
- Tyres
The slot car body is secured to this slot car chassis with 2 fixing
points at the rear behind the rear axle and by 1 fixing point behind
the front axle. This is the standard form factor for the resin and plastic
body kits readily available.
About the author:
Gary Harding has been working with Scalextric cars for over 35 years
and now operates Scalextric Car Restorations in the UK. Scalextric Car
Restorations is a Worldwide internet based business that offers for
sale high quality Scalextric cars and Scalextric parts from the 1960s
to the present day. All the restoration work is carried out to the highest
standards with the highest quality parts available. Only the best cars
are selected and the final result is a car that is genuinely like new.
Further help and advice relating to this article or Scalextric cars
in general can be found at:
http://www.scalextric-car.co.uk