Sooner or later, every motorist is faced with the need to carry out maintenance or minor repairs of his vehicle. Oil replacement, suspension check, underbody inspection for corrosion – all these operations require convenient access to the bottom of the car. Mini flyover in the garage It is an ideal solution for those who value their time and comfort, but do not have the opportunity to equip a full-fledged observation pit.
Unlike a stationary pit, which requires complex earthworks and is often impossible due to the high groundwater level, a compact flyover takes up a minimum of space and can be assembled in any convenient corner. You don’t have to dig deep trenches or worry about waterproofing walls. It is enough to have a flat platform and a minimum set of tools.
This article will help you understand the intricacies of designing and building a reliable structure. We will consider the choice of materials, the calculation of dimensions for a particular car and the nuances that will ensure safety during the work. Homemade flyover This is not just a wheel stand, but a serious engineering structure that requires a competent approach.
Selection of design type and calculation of dimensions
The first step to creating a functional repair site is to determine the type of structure. There are two main options: a single-tub overpass and a two-tub one. The one-tub structure is one platform, which is driven by two wheels on one side, while the other side remains on the ground. This saves space, but requires the use of additional stands for body stability.
The two-staff version, consisting of two separate platforms for each side, is more versatile and safe. It allows you to lift the car as a whole, ensuring a smooth position of the body. Calculation of dimensions critically important: the length of the race ladder should be sufficient so that the clearance of the car does not allow the bumper to touch the ground when lifting. Usually this distance is from 1.5 to 2 meters.
The width of the work site should exceed the width of the track of your car with a margin of 20-30 centimeters on each side. This will provide a comfortable ride and the possibility of maneuver. The height of the lift usually varies from 30 to 50 centimeters, which is the optimal value for lying down or sitting on a low stool.
- 📏 Length of the race ladder: minimum 1500 mm for passenger cars.
- 📏 Platform width: at least 600-700 mm on one side.
- 📏 Height of lift: 300-500 mm (depending on the height of the master).
When designing, consider not only the current car, but also the possible purchase of a larger vehicle in the future. Metal frame It makes it easy to build up the structure if you lay this opportunity initially. It is also important to provide wheel limiters so that the car does not slip off the platform during repairs.
Required materials and tools
The quality and durability of your future mini flyover directly depend on the materials chosen. The basis of the design is most often made of steel profile pipes or channelers. For the frame ideal channel No10 or No12, which is able to withstand significant loads without deformation. An alternative can be a profile pipe with a thick wall, for example, 100x100 mm.
A fluted metal sheet of at least 4-5 mm thickness is used for the working surface flooring. Rifling is necessary to prevent wheels from slipping, especially in winter or in the presence of dirt and oil. The use of a smooth sheet is strongly discouraged, as it poses a direct security threat.
⚠️ Attention: When buying metal, pay attention to the presence of corrosion. Rust metal loses its load-bearing capacity, and the use of such materials can lead to the collapse of the structure under the weight of the car.
To assemble the structure you will need a welding machine, a grinding machine (Bulgarka) with metal discs, a building level and roulette. Also do not forget about personal protective equipment: welding mask, edges and protective glasses. Welded seams They must be done qualitatively, with full provariance, as they take on the main load.
☑️ Pre-purchase inspection of materials
In addition to the main elements, corners will be needed to create stiffness edges and edges. Ribs are installed under the deck in increments of 30-40 centimeters, which prevents the metal from deflecting under the weight of the machine. For finishing, a metal primer and wear-resistant paint will be required, preferably a hammer effect, which will hide small defects and protect from moisture.
Step-by-step instructions for assembling the frame
The assembly of the frame begins with the preparation of the base. Cut the channel or profile pipe into segments according to your drawings. The length of the longitudinal beams should correspond to the length of the overpass, and the transverse beams should correspond to the width. First, two side frames are assembled, which are then connected by crossbars.
Welding must be done on a flat surface, constantly monitoring the geometry building level. Distortions can lead to the fact that the car will stand crooked, which is dangerous when carrying out work. Welding joints cleaned by the Bulgarian from slag and checked for the absence of cracks.
Welding sequence:1. The corners of the frame.
2. Diagonal check.
3. Complete joints.
4. Sew cleaning.
In the next step, the stiffness ribs are welded. They can be made of the same profile pipe of a smaller cross-section or corner. The distance between them should not exceed 40-50 cm. The more often the ribs are located, the more rigid the design is obtained, but the higher the consumption of materials.
- 🔨 Use magnetic cornstones to fix parts under 90 degrees.
- 🔨 Make the slings from different sides before the final welding.
- 🔨 Check the absence of a "screw" at the finished frame.
To the frame does not lead from the temperature when welding long seams, cook them in small areas (5-10 cm) in a chessboard order, giving the metal to cool.
Pay special attention to the arrival area. Here the frame should be strengthened, since it is on this site that the dynamic load at the time of the car arrival falls. You can use a larger cross-sectional tube or a dual profile. Structural reinforcement In critical points - the key to the long service of your flyover.
Installation of flooring and raceways
After assembly of the main frame, they proceed to the installation of the flooring. The riffled sheet is cut to the size and placed on the prepared stiffness ribs. Fixing is carried out by welding the sheet to the frame. Welding is performed with short seams around the perimeter and in places adjacent to the ribs, so as not to overheat the metal and not cause its deformation.
The tracks are the most important functional element. They shall have a smooth angle of inclination. A steep rise is dangerous because the car can tick a bumper or "bellied". The optimal angle of inclination is 15-20 degrees. The stairs can be removable or welded. Removable structures are more convenient to store, but require reliable fixers.
| Parameter | Recommended value | Note |
|---|---|---|
| The angle of the ladder | 15-20 degrees. | Depends on the car clearance. |
| The thickness of the flooring | 4-6 mm | Riffled steel (rhombus/lentils) |
| Borough height | 50-70 mm | Prevents slippage |
| Rib step | 300-400 mm | Under the flooring |
On the outer edge of the work site and ladders, it is necessary to weld the sides 5-7 cm high. They perform the function of insurance, not allowing the wheel to slide from the platform to the side. Bortices are mandatory for any overpass, regardless of its height. Inside the work area, you can also make small stops for wheels to fix the car in the desired position.
For ease of operation on the ends of the ladders often welded loops, if they are removable, or make special cutouts for capture by a forklift, if you plan to move the entire structure. The surface of the metal after welding should be carefully cleaned of scale.
Corrosion protection and finishing
Metal in garage conditions is constantly exposed to moisture, reagents from wheels and mechanical damage. Therefore, high-quality anticorrosion treatment is not just a cosmetic procedure, but a necessity. Before painting, the entire surface must be degreased and covered with a primer on rust.
Best proven alkyd or epoxy soils that create a strong film and provide adhesion of the finish layer. Grounding It should be carried out in two layers, allowing each to dry according to the manufacturer's instructions. Pay special attention to welded seams and internal corners, where moisture accumulates first.
⚠️ Attention: Do not use nitro-emali or conventional oil paints for the final coating. They quickly wash under the wheels and crack. Choose specialized wear-resistant paints for floors or hammer enamel.
The finishing coating is applied after the soil is completely dry. Hammer paint not only protects the metal, but also hides small irregularities of welding, giving the product an aesthetic appearance. The color is better to choose light (gray, light blue), as on a dark background, oil stains and debris are worse visible, which can lead to slippage.
How to paint the overpass cheaper?
To save you can use bitumen mastic as a base layer, but on top it is necessary to apply wear-resistant paint, otherwise the mastic will stick to shoes and wheels.
After drying the paint, it is recommended to check the reliability of all the compounds again. If bolt joints were used for collapsible elements, they must be stretched. The finished overpass should look neat and not have sharp edges that can be injured in the process.
Rules of safe operation
Even the most durable design requires compliance with safety regulations. Before each race, check the stability of the overpass on the floor. It should not be wobbled or shifted. Under the wheels, put recoil stops (shoe) immediately after the car stops, even if you are inside it.
To enter the overpass should be slow, without jerks and sharp braking on the ladder. The movement should be smooth. If the overpass is installed on a slippery floor (for example, on tile), it is desirable to put rubber mats under its supports or fasten it to the floor with anchors, if the design of the room allows.
- 🛑 Always use recoil stops for free wheels.
- 🛑 Do not rock the car on the overpass while working.
- 🛑 Regularly check the condition of welded seams and the integrity of the flooring.
Regular examination The design will help to identify cracks or deformities at an early stage. Once a year, it is recommended to update the paint coating in places of active wear. Do not exceed the maximum load that your overpass is designed for. For passenger cars, a safety margin of 2 tons is usually enough, but for SUVs, calculations should be more serious.
Safety is paramount: Never work under a car unless additional safety stands are installed, even if the car is on a flyover.
Frequently Asked Questions (FAQ)
Do I need to make a viewing hole under the overpass?
No, the mini overpass is just designed to replace the observation pit. You work from above, lifting the car above the floor. This eliminates problems with groundwater and complex waterproofing.
What is the minimum height of the overpass?
The minimum comfortable height is 30 cm. Below this value, it will be inconvenient to work lying down, since the tool will not fit at hand, and the space for maneuvering will be limited.
Can you make a tree trestle?
Theoretically, it is possible to use a 150×150 mm timber and thick boards, but the wood is less durable, absorbs oil and dries up over time. Metallic mini-fly It's more reliable and compact.
How to fix the overpass on the concrete floor?
For stationary models, anchor bolts can be used by drilling holes in the floor through holes in the base of the frame. For mobile versions, it is better to use rubber anti-slip linings.
Will the overpass withstand the SUV weighing 2.5 tons?
Yes, if during the calculation and welding, a channel No. 12 or a profile pipe with a thick wall was used, and the step of the ribs of stiffness does not exceed 30 cm. It is important to consider the weight distribution on the axes.