One of the most common problems for motorists is the lack of free space for the transport of large or oversized cargo. To correct this shortcoming, some manufacturers pack cars with extra roof racks. And those driver, whose car is not equipped with a roof rack, can make and install it yourself. But for the result to meet all expectations, it is important to understand how and from what to make the structure.
- The main purpose and the need to install
- 2 Preparatory moments
- 2.1 Selecting the type of design
- 2.2 Selection of material
- 2.3Determined with the type of attachment
- 3Production technology
- 3.1 Tools and Materials Needed
- 3.2 Drawing
- 3.3 Manufacturing
- 3.4 Fastening on the roof of the car
- 4Recommendations for operation
The main purpose and the need to install
The upper trunk, located on the roof of the car, is designed for the transport of oversized cargo, which for various reasons do not fit in the standard trunk. Very often, on the roof of a passenger vehicle, the driver is given to transport bicycles, bulky suitcases, fishing gear, and even building materials that have a greater length, such as boards or plinths.
Installation of the trunk on the roof of the car is needed not for all owners. A clear need to install additional baggage space arises in such cases:
- Frequent travel, long trips and travel “savage”, involving the use of dimensional tourist equipment and furniture;
- Occupation of active sports and recreation;
- Regular carpentry or repair work.
As an alternative to the upper trunk can make a trailer. However, its use requires certain driving skills and the mobile structure itself. Therefore, using the trunk on the roof of the car is easier.
There is no need to mount the trunk on the roof of a passenger vehicle if the car is used by the owner exclusively for movement.
Before you start making and installing the trunk with your own hands on the roof of the car, it is important for the owner to perform a number of preparatory work. These include:
- Selection of the most appropriate type of structure;
- The choice of the basic material from which the trunk will be assembled;
- Selection of the type of mounting that will be used for mounting the finished structure on the roof.
The final result of the work directly depends on the thoroughness of these events.
The choice of type of design
Roof racks for a passenger vehicle are of two types:
- Latticed, or arc-cross;
Arc-cross bars allow you to carry loads of various sizes on the roof of the car. In addition, such a design is easy to make yourself. Trunk boxes even though they have a more attractive appearance, but differ in small spaciousness. In addition, making boxes yourself is extremely difficult and very expensive.
That is why, considering the options for self-manufacturing roof racks, it is best to opt for lattice structures such as arc-cross member.
When planning to assemble and install a homemade roof rack, it is very important to choose the most suitable material for the design. It should be borne in mind that the weight of the product can adversely affect the speed and maneuverability of the machine, as well as fuel consumption, significantly increasing it. Because you should not use heavy materials.
The best options for materials for the manufacture of the trunk are light and soft alloys of metals. Aluminum is ideally suited for this purpose, as it also has protection against corrosive processes. However, this version of the trunk will not be cheap. To significantly save money and get a good result of work, you can use profile thin-walled pipes as a material.
Determine the type of attachment
Fastening a homemade trunk on the roof of a car can be done in the following ways:
- Regular installation. May be carried out when the manufacturer has provided special mounting holes in the vehicle roof. Fixing the trunk at the same time carried out by bolting it to the body at several points around the perimeter.
- Universal installation. Performed by installing special mounts in the holes of the gutters.
- Installation on rails. These structural elements are long longitudinal side rails placed on the roof of the car.
The most convenient and gentle way of fixing the trunk for a car is its installation on rails. These items are usually made of plastic.
To quickly, correctly and efficiently make your own trunk on the roof of the car, it is important to carry out the work in the following sequence:
- Prepare all the necessary materials and tools.
- Make a drawing of the future design, as well as the principle of its installation.
- Make the trunk according to the measurements and the developed design drawing.
- To fix the finished trunk on the roof of the car in the chosen way.
Before starting work it is important to make measurements of the roof of the car on which the trunk will be installed. And when developing a drawing of a future trunk, take into account not only this, but also the geometry of the roof.
Necessary tools and materials
The main part, without which it can not do in the manufacturing process of the trunk, is a suitable metal. Also in the process of working such components and devices will be useful:
- Welding machine;
- Bulgarian with nozzles for cutting metal;
- Polyurethane foam;
- Clamps for car silencers;
- A set of grinding tools;
- Fiberglass whose density is not less than 300 g / m2.
For the final stage of the creation of the trunk and ensure its long-term operation, you will need a car paint. Paint color can be any. However, it is best to look at the car trunk, painted in the tone of the car body, as well as silver or black.
To create a drawing of the future trunk, it is necessary to make a number of measurements:
- Measure the distance between the existing rails;
- Calculate the length of the roof and determine the size of the indents from the edge.
Considering the weight of the metal components and the required load carrying capacity of the trunk, the required amount of material is calculated, and the appearance of the future structure is also schematically depicted.
After all the calculations have been made, it is necessary to draw up an exact drawing of the dimensions of the parts planned for the manufacture of the boot on the car, with the dimensions laid on the chart. In this case, the drawing must necessarily contain the following structural elements:
- Overall dimensions of the product;
- Length and placement points of transverse reinforcement jumpers;
- The height of the sides of the future design;
- The bottom of the trunk.
When developing the project, it should be taken into account that roof boxes, having a rectangular or square shape, create substantial air resistance during the movement of the car. Because of this, the aerodynamic performance of the machine can be seriously affected. To avoid this, it is recommended to make the trunk with a streamlined front side.
The process of making a trunk on the roof of a car with his own hands has the following sequence of actions:
- Carefully examine the created project drawing.
- Cut metal to create a trunk frame. The work is done with the help of the grinder.
- From a suitable metal grinder cut elements, which will then be the ribs of the product. In the absence of the need to transport very heavy loads, it is enough to prepare two longitudinal and transverse elements.
- Boil together pieces of metal so that you get two identical rectangles. One of them will be the bottom of the trunk, and the second is needed as a side.
- Strengthen the lower rectangle by welding to it, at the same distance from each other, stiffeners.
- Splicing between the bottom of the structure and side. This can be done by welding at the corners of rectangles placed one above the other, and at several points on the sides, metal rods or tubes smaller than the main structure of the diameter.
At the end of the welding, the metal is lightly polished and painted in the color chosen for the construction.
Mount on the roof of the car
To install the trunk on the roof of the car with their own hands will need rails mounted on the sides. If not, these items can also be made independently. For this you need:
- From a metal pipe using a grinder, cut two pieces of the same size that fit the length of the roof.
- A polyurethane foam is applied to the metal with a copious layer on all sides and left to dry completely.
- After curing of the foam, with the help of grinding tools, the products are given the necessary shape.
- The resulting cross in 2-3 layers are covered with fiberglass.
- Ready railings are painted black, or any other suitable color.
After that, the rails are mounted on the roof of the car with clamps for car mufflers. All excess parts of the clamp are cut on a mandatory basis so that in the end only a flat plate is obtained on the railing. Further, symmetrical mounting holes are drilled on both sides in the rails. In the same points it is necessary to drill and prepared plates. After these manipulations, the cross member is fixed to the roof of the car with bolts. If the products do not fit tightly, a small rubber gasket can be laid between the plate and the railing.
Ready trunk mounted on rails with brackets. In the absence of crossbars and unwillingness to do them yourself, the trunk can be attached to the roof of the car directly. However, in this case, you will have to drill holes for the brackets in the body of the car, and fix the roof rack with them.
Recommendations for use
For long-term and successful operation of the self-made trunk, the product must be periodically cleaned from road debris, polished and repainted. Choosing metal pipes as a material, a decorative protective coating should protect the product from corrosive processes.
Also, in order for the trunk to last for a long time, it is important not to overload it, but when filling it is necessary to carefully distribute the weight of the baggage over the entire construction area.