Search for drawings on the boat, known in catalogs as AKS-4 or AKL-4It is often the first step for enthusiasts who decide to build a reliable metal boat DIY. This project, developed in Soviet times by designer A. N. Koksharov, remains one of the most popular among small craft enthusiasts due to the ease of contours and the availability of materials. You are looking for specific sizes and cutting schemes to begin construction, which can become a lifelong work of your family.
It is important to note that under the abbreviation LAX This is a model that is often implied, although there are variations in spelling in different sources, and the size of the vessel allows it to be used for fishing on large reservoirs and for family trips, but accuracy when transferring drawings to metal is crucial here. A mistake of several millimeters when cut can lead to difficulties in assembling the frame, so you need to approach the study of documentation with the utmost care.
In this article, we will discuss in detail the basic dimensions of the hull, the thickness of the skin and design features that must be considered before starting work. You will learn why this project is so loved by homemade craftsmen and what nuances it hides, seemingly simple geometry. Correct understanding of the drawings is the guarantee that your future boat will not only be beautiful, but also safe on the water.
General concept and history of the project
Project boat AKS-4 (AKL-4) was designed as a versatile vessel for use in challenging environments, and the goal was to create a boat that could be assembled in garage conditions using a minimal set of tools and standard sheets of metal, which is why the drawings are dominated by straight lines and simple contours, which greatly facilitates the process of flexible and welding compared to more complex marine forms.
The design is based on a flat-wheeled bottom that provides good swelling and stability on the course. Unlike the completely flat "Kazak", this model behaves better when moving against the wave, hits less water and is more comfortable for passengers. Aluminum alloyThe recommended for construction allows you to get a lightweight body that is easy to pull ashore and transport on a trailer.
The uniqueness of the project is that it's modular and adaptable to the specific needs of the owner. Many builders have made changes to the location of the cockpit or the height of the transom, but the basic dimensions have remained the same, which confirms their optimality. If you're planning to build, it's important to understand the philosophy of the author: simplicity should not come at the expense of strength, so power set is done with a margin.
Overall dimensions and main specifications
Before proceeding with the purchase of metal, you need to clearly represent the final dimensions of the boat. AKS-4 It is a small pleasure-fishing vessel, which limits its dimensions for registration and operation, and the main dimensions are defined to ensure maximum usable cockpit area while maintaining good vigour.
The hull is 4.2 meters long on the deck, which is the classic size for a four-seater boat. The width of the midsection (the widest part) is 1.6 meters, which provides sufficient stability even when moving passengers. The height of the side on the midsection is usually taken to be 0.6-0.7 meters, which allows you to safely be on the water even with slight excitement.
Special attention should be paid to draft and load capacity. When fully loaded, the draft does not exceed 0.3 meters, which allows you to approach sloping banks. rated carrying capacity is about 400-500 kg, including the weight of the crew, engine and equipment. Exceeding these limits can lead to a decrease in freeboard height and compromise safety.
| Parameter | Meaning | Unit of measurement |
|---|---|---|
| Longest length | 4200 | mm |
| largest width | 1600 | mm |
| Height of board | 650 | mm |
| Mass of the body (without equipment) | ~130-150 | kilogram |
| Recommended engine power | 25 | hp |
The dimensions of the AKS-4 boat fit perfectly into the requirements for registration in the GIMS for vessels up to 5 meters long, which simplifies legal registration.
Detailing of drawings: skinning and set
Drawings of the boat AKL-4 For the lining of the bottom, which takes the main loads when hitting the wave and mooring, it is recommended to use a sheet with a thickness of at least 3 mm The side and deck can be made of metal 2 mm thick, which allows you to reduce the overall weight of the structure without loss of strength.
The hull's power kit consists of frames, stringers and keels. The hull shaped spans are usually made from a 25x25x3 mm corner or band of appropriate width. The keelson, running along the diametric plane, serves as the main carrier "spine" of the boat and must be executed with extreme care, often using thicker metal or paired profiles.
When working with drawings, it is important to observe the sequence of assembly. First, a quilt line is assembled on a slip or flat area, then the frames are installed, and only after that the skin begins. Welded seams must be made solid, without omissions, using argon welding for aluminum to ensure complete tightness.
☑️ Checking readiness to reveal
⚠️ Note: When using drawings from different sources, carefully check the dimensions of the frames. In some publications, typos or zoom changes may have been made, which will lead to a skewed body during assembly.
Materials and assembly technologies
The choice of material is the foundation of the durability of your boat. AKS-4 The best choice is aviation aluminum brand AMG5 or AMG6These alloys have high corrosion resistance in sea and river water, as well as excellent weldability. The use of ordinary dural (duraluminium) is not recommended due to its low corrosion resistance and tendency to electrochemical corrosion in water.
The assembly technology requires purity and precision. Before welding, the edges of the parts must be cleaned to a metallic shine, defatted and dried. Aluminum quickly oxidizes in air, forming a refractory film that prevents the formation of a quality seam, so the delay between stripping and welding should be minimal.
To strengthen the structure and prevent deformation during welding, it is recommended to use precipitators every 50–100 mm before welding the main seam, this allows you to fix the parts in the right position and minimize the metal leash from thermal exposure. After welding, the seams are necessarily cleaned and, if necessary, subjected to color defects to check for the absence of cracks.
Why can't we use steel for this?
Using steel instead of aluminum for the AKS-4 boat is possible, but will lead to a significant weight gain (by 2.5-3 times). This will require a more powerful and heavy engine, increase fuel consumption and reduce stability. In addition, a steel boat will require careful anti-corrosion treatment and painting, while an aluminum one can be operated even without paint (although this is not aesthetically pleasing).
Features of the transom and installation of the motor
Train boat AKL-4 It is a critical element that perceives the traction force of the engine. In drawings, it is usually performed in reinforced form, using a sheet thickness of 4-5 mm or a double sheet with internal stiffness ribs. The inclination angle of the translance (transe angle) is standard 10-12 degrees, which meets the requirements of most outboard motors.
When installing the engine, it is important to consider the height of the lower unit. For a boat with a length of 4.2 meters, the optimal will be the use of a motor with a lower unit S (short leg) or L (long leg) depending on the load. If you plan to use a motor with a capacity of more than 15 hp, the transom is recommended to strengthen by welding additional scarves or increasing the thickness of the metal in the mounting area of the rods.
You also have to make sure you can adjust the tilt of the engine or use a hydraulic lift if you have the budget, which will improve handling and compensate for the change in centering when there are different numbers of passengers, and make sure you have drain holes in the transom area to remove water that has entered the cockpit.
⚠️ Warning: Never attach a powerful motor to a plywood pad on a transom without a metal base. Vibration and traction will quickly destroy the tree, resulting in the loss of the engine overboard.
Interior arrangements and deck
After welding and checking the hull for leakage (be sure to test afloat or filling with water), the stage of internal arrangement begins. AKS-4 Often made removable or partially removable to facilitate access to interior surfaces and drying. For the deck, a fluted sheet ("quintet") with a thickness of 2-3 mm, which does not slide even in a wet state, is well suited.
Inside the hull, it is advisable to install knobs for storing equipment that will simultaneously serve as cans (seats), the location of the knobs should ensure free passage to the nose and not disturb the centering of the boat. All internal elements should also be made of aluminum or moisture-resistant plywood with high-quality impregnation.
Don't forget to install the rim bolts to anchor the tack and mooring ends. The bow rim should be reinforced by a large diameter washer on the inside of the board. It's also recommended that you have space for the power plugs if you plan to use the oars as a backup engine.
For comfort on fishing, install special rod and sonar mounts on the deck, which can be made from PVC pipes or buy ready-made marine accessories, fixing them on aluminum slats.
Frequently Asked Questions (FAQ)
Where to find the original drawings of the AKS-4 boat in good quality?
The original drawings were often published in Boats and Yachts or Model Designer magazines in the 70s and 80s, and in modern format can be found on specialized powerboating forums or in the archives of homemade boat sites. Look for files with the.dwg extension or quality PDF scans.
Can an AKS-4 be built from steel?
Technically, this is possible, and there are examples of this. However, steel is much heavier than aluminum, which will require changes in the buoyancy and engine power calculations, and the steel boat will be corrosive and require constant paint care, while the aluminum hull requires little maintenance.
Which engine is best for this project?
The best choice for a boat with a length of 4.2 meters and a weight of about 150 kg will be an outboard motor with a capacity of 9.9-15 hp (for example, Yamaha, Tohatsu or their Chinese counterparts), which will provide glides with two passengers and cargo. Motors with a capacity of 20-25 hp will allow higher speeds, but require strengthening of the transom.
Do I need to register such a boat in the GIMS?
Yes, the AKS-4 is subject to mandatory registration with the GIMS, since its length exceeds 3 meters (or the weight of an unequipped vessel exceeds 200 kg if the engine is used).
Independent construction of the boat project AKS-4 is a cost-effective solution that allows you to get a high-quality vessel, fully adapted to your personal requirements.