How To Build a Challenging and Aesthetically Appealing RC Track in your Backyard (With Sketch Drawings)
How To Build a Backyard RC Track
RC Track Dimensions and Design
Setting Out Track Lines and Curves with Marker Pins
Building the RC Racing Track
Building Elevated Ground on your RC Track (Dirt Jumps, Hill Climbs and Rising Slopes)
RC Track Barriers
RC Track Jump Design
RC Track Drive-Through Tunnel
RC Wet Track
If driving an RC is one of your favourite hobbies or pastimes, then you would want to build a racing track in your backyard to drive your RC car or truck. What does RC stand for? The acronym stands for Remote Control or Radio Controlled. These trucks come in various sizes, shapes and engineering / performance specifications ranging from cheap models ($60) to high end models tagged at $800 or above. The range (control distance), speed and battery longevity are some of the most important things you have to consider when choosing an RC truck. There are cars built for off-road conditions and those built for level surfaces, so you have to know which type is suitable for your race track. A formula-1 RC car will be suitable for a hard level surface such as concrete, asphalt or well compacted earth road. You will not enjoy the experience with this car on a bumpy, sandy, muddy, rocky or rough road. You also have RC trucks built for all terrain, and the specially made RC rock crawler.
Kids and adults alike are into RC car racing and as expected, they will have different choices of cars and racing tracks. Kids might prefer small cars and a smaller race course. Adults will go for big RC trucks and a much larger racing ground. In many cases, grown-ups are interested in truck performance (e.g. speed, manoeuvrability etc.) and challenging courses. If this is the case, then you might want to build a race course that simulates an actual Rally race course or Formula-1 race course. RC car racing tournaments conducted by IFMAR are held each year with championship winners from Europe, USA and Japan dominating the event.
In this post, we are going to discuss how to build an RC track in your backyard for all kind of course terrain and ground conditions. Why is an all-terrain course much more interesting and exciting than a single terrain race course? Well, the problem with making a monotonous terrain is that it gets boring sooner or later, since you have no difficult turns, tricky roads, obstacles and other challenges to overcome. You want to feel like a champion after completing your Grand Prix rally or Formula-1 campaign, right? A straightforward, easy and mono-terrain racing track is not going to cut it or give you the challenge.
How To Build a Backyard RC Track for All Terrain
Building an RC track like any other outdoor project such as landscaping should involve a lot of planning before the actual construction begins. Most RC tracks out there look quite simple and hurriedly done, but if you are not just looking for a functional RC track but one that also aesthetically fits in with your environment, you will have to put in a lot of planning and design into it. Look, if you are not careful, an ugly and shoddily built mini race course can ruin the look of your backyard. Do you have an amazing garden and landscaping features in your backyard that were built for aesthetic or ornamental purposes? If so, then you would not want to ruin your yard with a racing track that looks like a quarry or construction dump site. You have to design your track so that it fits in harmoniously with the yard, landscaping and garden.
RC Track Dimensions and Design
The Monte Carlo rally track is one of the most challenging tracks to race on. The dude here made a good job of illustrating the tricky situations and obstacles you will encounter when negotiating the Monte Carlo rally track. There are uphill climbs, adrenaline pumping downward slopes, acute slow turn bends, narrow exits and tunnels. We are going to design an RC course based on the Monte Carlo Grand Prix rally track map. This makes it easy for the track designer because it cuts out the task of figuring out the type of track pattern or race circuit suitable for a challenge. You can modify the race circuit as you want, adding your own ideas, features and extensions, but the basic idea is that you already have a template to work on. No more brainstorming.
Taking the Monte Carlo rally track, you have to convert and reduce the actual dimensions to a model that will fit in a selected portion of your backyard. Find a suitable area in your backyard to build the track, as long as the track model fits on the site that will be fine.
To find the right track dimensions (width), you have to measure the size of your RC truck (the car width). You will also need information about the actual Grand Prix track, its width and lanes, as well as the width of the actual Rally car.
Work out the ratios of the track width versus the rally car width. You will need this information later when designing and drawing the RC track on a CAD program like Google Sketchup or AutoCAD.
Note that instead of using the Grand Prix rally track as a base for determining the size of your track, you can also use a public road or highway. A road or highway with at least three lanes will be suitable to provide a wide passage and more room for movement (turning, swerving, circling, skidding etc.)
After working out the width ratios of the Grand Prix track to the Rally car, you need to scale them down to your backyard plan. To do this, you will use the RC truck width as your base dimension to find the width of the RC track. If you are into mathematics, this is an easy task:
Monte Carlo Rally Track:
Width of Grand Prix track: W1 = 36 feet (11 metres)
Width of World Rally car: W2 = 1770mm (5.81 feet)
Ratio W1:W2 = 36:5.81 = 6.20:1
Scale on Google Sketchup: 721mm represents 270m (721mm:270m)
Map scaled (enlarged) by a factor of 4 in backyard plan
Enlargement: 2884mm represents 270m (2884mm:270m)
Width of RC track: W3 = ?
Width of RC truck: W4 = ?
Widths of various RC trucks:
To find the width of an RC track W3, we have to first find the width of an RC car W4. The manufacturers width of different RC cars is shown below:
Maxxrace RC Truck = 178mm (7 inches)
SpeedDemon RC = 191mm (7.5 inches)
Jack Royal 4WD Rock Crawler = 6.5 inches (165mm)
Redcat Racing Camo TT Pro 1/10 = 12.2 inches (310mm), 7.95 inches high (202mm)
Redcat Racing Terremoto V2 1/8 = 15 inches (381mm) wide wheel base (2 feet in length), 19 inches high (483mm)
Rally RC Cars:
Traxxas AWD Ford Fiesta ST 1/10 = 11 inches
Kyosho EP 4WD R/S DRX Demon 1/9 = 10.23 inches
Looking at the dimensions above, if we want to build an RC track for a Redcat Terremoto V2, which is the biggest RC truck in its class with a wheel base of 15 inches (381mm), then our RC track width would be 6.20 times the width of the Redcat Terremoto V2. This is a track to car width ratio we calculated previously. So in this case, the width of the RC track will be 15 inches x 6.20 or 381mm x 6.20 in metric units:
15 inches x 6.20 = 93 inches,
381mm x 6.20 = 2362.20mm,
For practical purposes, you won’t need this width for your backyard track because it’s too wide. You won’t be racing 4 or 6 cars at a time so a width of 93 inches (2362mm) is not needed. Your backyard will most probably be too small to accommodate a track of this width, so you should reduce your track to a double lane, suitable for racing one or two cars:
Calculation of two lane track width for Redcat Terremoto V2:
15 inches x 2 = 30 inches,
381mm x 2 = 762mm
A two lane track 30 inches (381mm) wide will be suitable for a Redcat Terremoto V2.
Calculation of two lane track width for Redcat Racing Camo TT:
12.2 inches x 2 = 24.4 inches,
310mm x 2 = 620mm
A two lane track 24.4 inches (310mm) wide will be suitable for a Redcat Racing Camo TT.
You can calculate the racing track widths of other RC car models using the same method outlined above.
The racing track plan below is based on the Redcat Camo TT. This track is also suitable and wide enough for a Terremoto V2.
Now that you have the track dimensions and design figured out, you have to draw the plan layout and landscape features on a CAD program like Google Sketchup or AutoCAD. On the CAD program, draw the track, kerbs, ground slope, tunnels and other features, then put some rendering to make it semi-realistic. Google Sketchup is recommended for this project because it’s free and you can view the drawing in 3D.
Most importantly, track drawings are needed to guide the builder during the construction stage. You will need to refer to the drawings to set out levels on site with profiles and stringlines, marking the ground with lime / spray paint for excavation and filling. The track has to be built according to specifications and schedules laid out on the drawings. Print a paper copy of the drawings that you can roll out on the site for reference.
This backyard RC track is going to cover a rectangular area of 14,364 x 9,815mm:
Before any excavation or construction begins, you have to clear the site of all rubbish, debris, bushes, grass and vegetation. Call the municipality or utility operators (811 Dig Safe) to come locate and identify the position of all underground services such as water, sewer and gas pipes.
Setting Out Levels with Profiles and Stringlines
Mark the rectangular perimeter on the ground using corner profiles and stringlines. Hammer the corner profiles into the ground, then tie and run taut stringlines over the tops of the profile boards. Make sure the stringlines are perpendicular to each other on all four sides, and run two taut diagonal stringlines between the diagonally adjacent corners. If these two diagonal stringlines are equal in length, then you have a perfect rectangle. Now that you have profiles and stringlines in place marking your racing track construction site, you have to excavate and level the site.
Excavate Site to Reduced / Strip Level
Excavate the site and strip topsoil to an appropriate reduced level, about 75mm to 100mm deep. Alternatively, instead of strip excavation, you can scarify the ground to a depth of 100mm with a scarifying machine. Before scarifying, make sure the ground is wet and loose enough to be scarified. If your site is rough, uneven, sloped and undulating, you have to level the site. Cut the slopes, excavate the ridges and bumps, and fill holes, depressions and low lying areas with excavated soil. Break up lumps of soil and spread evenly over the site.
After levelling the site, you have to wet and compact the ground with a vibratory roller. Add additional layers of soil, moisturizing the soil with water if need be and compact the soil layers until the ground is firm and stable (to 95% Mod AASHTO density).
Setting Out Track Lines and Curves with Marker Pins
At this point, you should have flat and level ground on which to set out your track lines. Your racing track will have linear as well as curved lines (bends, turns, arcs etc). While setting out straight lines is easy, setting out curves and arcs will require a lot of skill. You will need stringlines and steel marker pins to set out the tracks. Steel marker pins are spikes about 300 to 500mm long, which can be hammered into the ground at suitable intervals to mark consecutive positions along an arc or curved line. A straight line will need two marker pins, one at each end. An arc or curved line will need more than two pins to define the curve.
The Monte Carlo track or any other Formula-1 racing track for that matter has numerous curves, and to properly set out and define the curves, you have to put a grid over the drawings on your CAD program. These grids will be reproduced on site. For this project, we are going to apply an 16 x 11 grid (with 96 squares) over the track drawing, then reproduce the drawing on architectural blueprint paper which can be rolled out on the site for reference.
Since we already know the size of our construction site (14,364 x 9,815mm), we should divide the site into grids. Each grid will be about 898 x 898mm. Mark the grids on this rectangular site using spray paint or lime. This should be an easy task and highly accurate because the dimensions are known.
Between and within the grids marked on your site, start drawing the track lines with spray paint or lime. Choose a starting point, let’s say Turn 1 on the plan. In the grid where Turn 1 is located, draw the precise track line or curve as shown on the blueprint. Do this for the next consecutive grids until you have completed the track.
After drawing (marking) the track lines on prepared ground, you have to drive in steel marker pins along the lines at a suitable spacing of at least 300mm c/c. A straight line will need two marker pins, one at each end. An arc or curved line will need more than two pins to define the curve. Put the marker pins at 300mm c/c.
Tie and run a taut stringline across the marker pins. The stringline should follow the spray paint lines (track lines). Now, that’s it. You are done with setting out lines and curves for your track on the site.
The next step after setting out the track is excavating and building the tracks.
Building the RC Racing Track
Building the RC track is the fun part. You have a lot of options to choose from. At this stage of the project, it’s time to decide the type or types of road surfaces and terrain you want, the road conditions, changes in elevation etc, and other landscape features.
Track Elevation Changes:
Approximate track elevation changes, height above sea level
We have to start by determining the ground elevation changes. This will make it easier to draw the terrain on our CAD program later on. The elevation changes shown below are based on the Monte Carlo track in Monaco:
Turn 1 – 60m
Turn 2 – 80m
Turn 3 – 86m
Turn 4 – 89.5m
Turn 5 – 75m
Turn 6 – 70m
Turn 7 – 60m
Turn 8 – 55m
Turn 9 – 55m
Turn 10 – 50m
Turn 11 – 50m
Turn 12 – 50m
Turn 13 – 49m
Turn 14 – 49m
Turn 15 – 47.5m
Turn 16 – 47.5m
Turn 17 – 47.5m
Turn 18 – 47.5m
Turn 19 – 53m
Turn 20 – 50m (Turn 20 comes immediately after Turn 19)
You next step is opening your CAD program (Google Sketchup) and marking the Turns shown above on your track drawing. After doing that, you have to draw vertical lines, heights above sea level representing your Turns or points. When you have marked all the Turns with their respective heights above sea level, you must join the tops of the vertical lines with horizontal or sloping lines that represent the track and terrain. The gradient of your track and terrain will be much more clear and visible in a 3D CAD program like Google Sketchup. After joining the tops of the vertical lines with gradient lines, you must connect the two sides of the track with horizontal lines to form a surface. Draw another enclosed perimeter on the vertical sides of the track to create vertical surfaces. That’s it, you have just created a 3D terrain and landscape.
Fill each section of the track with appropriate rendering (course) e.g. dusty soil (silt), asphalt, sand, sawdust, dirt, dead leaves groundcover, gravel, grass, wood mix groundcover, vegetation bark groundcover, bark chips groundcover, crushed rock/bricks and so on.
Building Elevated Ground on your RC Track (Dirt Jumps, Hill Climbs and Rising Slopes)
An exciting racing track will include elevated ground such as hill climbs and dirt jumps. To create elevated ground on your RC racing road, you must build embankments. Embankments are manmade mounds of earths made from excavated earth filling or imported material. An embankment looks like a trapezoidal prism in shape. In civil engineering, embankments are built to elevate ground level in road construction, and used as retaining walls in dam construction.
On an outdoor RC track, embankments are built to form hill climbs, dirt jumps and rising slopes. Clay is a good choice for building embankments because of its highly cohesive particles, low permeability and plasticity. Due to these properties, clay can be moulded into any shape and it also possesses a great deal of compressive strength and hardness when dry.
If you have loose soils on your building site (e.g. sand, loam, peat, sandy loam, silt, sandy silt), then you should stabilize the soil with an industrial stabilizing agent such as cement, lime, bitumen, pozzolana and gypsum. In civil engineering earthworks, weak and unstable soils under foundations are usually stabilized with binders such as Portland cement. A weak mixture of soil and cement (about 7.5 to 15 MPA), known as soilcrete will make the ground firm.
You can build your RC track embankments with soilcrete if clay is not available in your area. If the hill climbs and dirt jumps are very high, you might need to temporarily support the sides of the wet embankments with formwork or trench sheeting until the soil mixture is dry and hardened.
Whether you are using clay or soilcrete to build your embankments, you have to compact the filling in 150mm layers using a tamper or rammer. Compact each layer to about 90% Mod AASHTO density before adding another layer. Repeat the process until you reach the desired height for your elevated ground. Compaction eliminates and reduces the voids in the soil mixture, thereby increasing its compressive strength.
As long as you have a shovel, pick and rammer, you can build embankments. The sketch drawing below shows a cross section of an embankment on an RC racing track:
RC Track Barriers
Both flexible and semi-flexible plastic drain pipes such as HDPE, PVC, CPVC, PEX, PP, ABS and uPVC are often used as track barriers for an RC race course. Unlike steel, iron, bricks, stones and concrete kerbs, plastic track barriers are recommended because they won’t cause damage to your RC car. Alternatively, instead of drain pipes, some people use plastic rainwater gutters and downspouts.
But wait; there are many other materials that you can use as a soft wall for your track. Tin and aluminium are light and flexible. These properties make them very easy on colliding objects when knocked or bumped, leaving the RC car with no dent or crack. In this case, you may use aluminium gutters for your track barriers.
Another idea of a racing track soft wall or barrier is using geosynthetics also known as a geotextile or geofabric. Woven and non-woven geotextiles made of 100% polypropylene (PP) or polyester (PET) will be both okay. The advantage of a geotextile barrier is that it is flexible, shock absorbing, strong and very durable for external use in earthworks and exposed conditions.
To make a track barrier, rectangular steel tube framing with posts, horizontal top and bottom sections is enveloped with a geotextile canvas. The posts are embedded into the ground and the frame bottom is laid flush with the ground. The posts are F-shaped, enabling a canvas to be fixed between the top and bottom horizontal sections, with vertical posts situated 150mm behind the canvas and away from contact with the RC car in the case of a collision with the barrier. As you can see, the car will bump against the flexible geotextile canvas, preventing damage to the car.
For all types of barriers, the height of your track barrier will depend on the height of your RC vehicle.
RC Track Jump Design
Do you want to build an RC track jump in your backyard? Building an RC track jump is not much of a drama if you like woodwork. In designing your wood jump ramp, you have to consider some physics. The furthest horizontal distance you can jump is obtained at a tangent of 45 degrees, meaning that the maximum launch slope for your ramp should be 45 degrees. Slopes greater than 45 degrees and those less than 45 degrees will result in a jump that is shorter than the furthest horizontal distance. Assuming that conditions are normal, the longest jump you can have also depends on the speed of your RC car and the approach distance. If you want to have a longer jump, accelerate your car within a longer distance of approach.
R = horizontal range (m)
U = initial velocity (m/s)
G = acceleration due to gravity (9.8m/s²)
Ø = launch angle (measured in radians or degrees)
If you know the speed of your RC car and the track jump launch angle, you can calculate the distance that your car will jump.
Now that you have the physics of jumping right, you can start designing your jump ramp. We are going to illustrate two types of ramps with different setups. Ideally, it’s convenient to build a mobile ramp which can be temporarily fixed on the site and moved elsewhere when needed.
Maximum Speed of RC Cars and Trucks
Redcat Racing Terremoto V2 – 30mph
Team Redcat TR-SC10E – 42mph
A Redcat Racing Camo TT Pro – 18mph
Redcat Racing Volcano S30 – 65mph +
Tornado S30 – 51.23mph
Redcat Hurricane XTE – 45mph
Rampage XT – 25mph
Rampage MT Pro – 34mph
Traxxas X0-1 – 100mph
Hossim 4WD Offroad Monster Truck – 46mph
Redcat Racing Everest Gen7 Pro Sport – 7mph
Traxxas 4-Maxx 4WD – 60mph+
Hinged Foldable Jump Ramp:
A hinged foldable jump ramp is one of the simplest ramps you can make. This ramp has two hinged boards of equal size, and an adjustable chain hooked between the boards underneath to keep the V-shaped ramp stable and at an appropriate angle. If you are a DIY person, you can make this ramp at home. All you need is an ½ inch thick plywood board (13mm), two backflap hinges, four loop eye screws and two steel chains with a length which is equal to the maximum horizontal distance formed by the maximum obtuse angle between the V ramp in its wide open position. The chains must have lockable hook clips or snap hooks at both ends.
As you may have guessed, the advantage of a hinged foldable jump ramp is its adjustable chain which allows the ramp to be set at different slopes. You can set the ramp at whatever slope angle you like from say 5 to 30 Degrees. The other advantage of a V-ramp is that it is sloped on both sides, which allows the RC car to make a U-turn and approach the ramp from both ends.
So what is the appropriate size for your foldable hinged ramp? The size of your ramp will be determined by the size of your RC car. There are big, small and medium cars with different widths or wheel base. The width of your car should be used to work out the width of your jump ramp. As a rule, the width of your jump ramp should be 4 times the width of your RC car. A wider ramp width prevents the car from sidestepping the ramp or tipping over the side. The slope can be as long as the ramp width.
45 Degree Jump Ramp with Smooth Rounded Transition:
A 45 degree jump ramp as the name says is a ramp with a fixed slope inclined at 45 degrees from horizontal ground level. This wooden ramp has ½ inch plywood triangular side stringers (on both sides), connected and supported by horizontal bracing fixed between the side closers. Bracing is fixed on the bottom, top as well as under the ½ inch runway plywood cover.
A typical 45 degree jump ramp would be a triangular prism with a height of 2 feet, base length of 4 feet and width of 4 feet.
Height = 2 feet,
Base Length = 4 feet,
Width = 4 feet.
The problem with a straight ramp inclined at 45 degrees from level ground is that it is too steep for the RC car to climb without crashing or stalling. To solve this problem, you need a smooth rounded transition (curve) that doesn’t impede the flow and momentum of the car.
Smooth rounded transitions are usually built in tracks for bike dirt jumps. The concept can also be applied to RC car jump tracks. If you intend to build a ramp with a straight slope, you should reduce your slope to 20 degrees or less. Building a straight ramp is easy, but building a smooth curved ramp takes a lot of skill and design. You will need to make sketches on your notebook or CAD program to calculate the right radius or curvature for your ramp.
On your CAD program, draw the side elevation of your curved ramp. Start by drawing the base length (on the x-axis) and height (on the y-axis). Now, draw a straight-line slope completing the triangle.
From the apex of the triangle going down vertically, measure 18cm and mark the point. On this point, draw a horizontal guide line (dotted line) which is perpendicular to the height. This guide line will be parallel to the base. Draw a solid horizontal line 18cm from the point which we marked previously. Now, from the endpoint of this solid line, draw a straight slope line (at an angle of 45 degrees from the horizontal line.) which joins with the apex of the triangle. This straight line slope provides the 45 degree launch angle for the RC car or projectile. The remainder of the ramp will be a curved smooth transition or curved slope initializing the climb.
The above ramp slope was designed on graph paper or CAD program, so you have to transfer the design on your plywood board. In the workshop, you will need a 27cm 45 degree square set with two equal sides of 18cm. In this case, your straight launch slope will be 27cm long. Mark the lines on the plywood board as depicted on your graph paper or CAD program. To mark the line for the curved transition, you will need a stiff but bendable metal strip like a hand saw blade. This bendable metal strip flat bar should be about 4 feet long (long enough to fit between the curved transition on your plywood board). Clamp one end of the strip bar to the lower edge of the ramp and the hold the other end with your hand along the straight launch slope. Bend the strip bar slightly towards the base to get the curve you want, then hold the position and draw a line against the strip bar using a carpenter’s pencil. When you are done, remove the strip bar.
Your next step is cutting the plywood board along the marked lines. Clamp the board and use an electric hand-saw to cut along the lines. Repeat the steps outlined above for the other plywood side stringer.
RC Track Drive-Through Tunnel:
A drivethrough tunnel is an exciting addition on your RC track. There are many ways to build a tunnel. You can choose between a recessed tunnel and raised tunnel. A recessed tunnel involves digging a trench for the passageway with smooth sloping entries and exits where the car emerges from the ground/trench. The tunnel can be roofed with a low-lying roof providing headroom clearance for vehicles at the entry and exit ends. Since this tunnel is a depression excavated below natural ground level, it needs efficient drainage that will quickly drain away surface rainwater. Think of it as a bathtub, you will need to install drain outlets on the track surface. During a rainfall, the drain outlets will prevent pooling of water inside the tunnel.
In designing your RC tunnel, you should consider the height of the RC car. Add a headroom clearance of 100mm or more to the height.
A Redcat Racing Terremoto V2 is 19 inches high (483mm).
A Redcat Racing Camo TT Pro is 7.95 inches high (202mm).
Our track is 620mm wide, it will remain the same under the tunnel.
A second type of tunnel that you can build is the raised tunnel. In this tunnel, the natural ground elevation of the track is maintained (i.e. no trenches are dug). Instead, you will build the tunnel walls from ground level and roof the tunnel with appropriate cover. You can get creative here because there many options for building your walls and roof cover. The simplest tunnel that you can have is building a box-like structure made of timber framing and sheathing or steel dome frame with cover (something like an aircraft hangar or portal frame). But if you want something that aesthetically fits in well with your backyard garden, you have think out of the box.
An aesthetic idea for a backyard track tunnel is building a raised garden bed as a tunnel. The roof will be built as a planter bed for flowers, groundcover plants, grass or climbing plants. The sides may be covered with a transparent sheet like thick clear vinyl panels.
RC Wet Racing Course
A wet track provides fun for your driving, however you should be aware that some RC trucks are not made for wet and muddy roads. Whether it’s made for muddy roads or not, an RC truck will easily get stuck in mud if the puddle is too deep, swampy or sticky. As you drive in the puddle, within less than 2 metres, mud will get under the wheels too quickly causing the car to get bogged down.
With these circumstances in mind, the optimum mud course that you can have for your RC truck is one where the wheels are no more than 30%-submerged in the mud for a high suspension truck. If the wet course is a water body on hard surface with no mud, for example water on concrete, stone, gravel or asphalt surface, you can increase the wheel submersion to 80% for a high suspension truck, and 50% for a low suspension car.
When it comes to offroad driving and mud racing, the size of your tyres matters. A high suspension RC car with big tyres is the best vehicle for traversing an extreme muddy course. The bigger the size (diameter) of the tyres, the better.