Devices for lifting loads. Strengthening homemade lifting devices

Blocks and pulleys- simple mechanisms used to lift loads either with little effort or with effort in a position convenient for the user.

Blocks and pulleys consist of two parts: a wheel with a circumferential groove (pulley) and a rope or cable. A block, as a rule, is a device consisting of one pulley in a frame with a suspension and one cable. A pulley block is a combination of pulleys and cables. The principle of its operation is similar to the operation of a lever - the gain in force affects the increase in distance with theoretical equality of the work performed.

These mechanisms can be used independently of other lifting units, such as winches, hoists, cranes, and also as their parts.

The pictures show the operating principle block and pulley:

In Fig. 1a, a load weighing W1 is lifted using a single block with a force P1 equal to the weight. In Fig. 1b, the load W2 is lifted with the simplest multiple pulley system, consisting of two blocks, with a force P2 equal to only half the weight of W2. The impact of this weight is divided equally between the branches of the cable on which pulley B2 is suspended from pulley A2 by hook C2. Consequently, in order to lift the load W2, it is sufficient to apply a force P2 equal to half the weight of W2 to the branch of the cable passing through the groove of the pulley A2; Thus, the simplest chain hoist gives a double gain in strength. Fig. 1,c explains the operation of a pulley with two pulleys, each of which has two grooves. Here the force P3 required to lift the load W3 is only a quarter of its weight. This is achieved by distributing the entire weight of W3 between the four suspension cables of block B3. Note that the multiple of the gain in strength when lifting weights is always equal to the number of cables on which the movable block B3 hangs.

Rice. 2

In the past as a cable for blocks and pulleys flexible and durable hemp rope was used. It was woven with a braid of three strands, each of which consisted of many small strands. Pull blocks with such ropes were used wherever it was necessary to lift loads: on sea vessels, in agriculture, on construction sites. The most complex of them (Fig. 2) were often used on sailing ships. There they were needed to work with sails, spar parts and other movable equipment.

Over time, hemp edges were replaced by steel cables and cables made of synthetic and mineral fibers. They are more durable and wear-resistant. Pulley hoists with steel cables and multi-groove pulleys are integral parts of the lifting mechanisms of all modern lifting equipment. Pulleys blocks usually rotate on roller bearings and all their moving surfaces are forcibly lubricated.

A pulley block is a system of movable and fixed blocks connected by a flexible connection (ropes, chains) used to increase the force or speed of lifting loads. A chain hoist is used in cases where it is necessary to lift or move a heavy load with minimal effort, provide tension, etc. The simplest pulley system consists of just one block and a rope, and at the same time it allows you to halve the traction force required to lift a load.

Typically, lifting mechanisms use power pulleys to reduce the tension of the rope, the moment from the weight of the load on the drum and the gear ratio of the mechanism (hoist, winch). High-speed pulleys that allow you to gain a gain in the speed of movement of the load at low speeds of the drive element. They are used much less frequently and are used in hydraulic or pneumatic lifts, loaders, and mechanisms for extending telescopic booms of cranes.

The main characteristic of the pulley is the multiplicity. This is the ratio of the number of branches of the flexible body on which the load is suspended to the number of branches wound on the drum (for power pulleys), or the ratio of the speed of the leading end of the flexible body to the driven end (for high-speed pulleys). Relatively speaking, the multiplicity is a theoretically calculated coefficient of gain in strength or speed when using a chain hoist. Changing the multiplicity of the pulley system occurs by introducing or removing additional blocks from the system, while the end of the rope with an even multiplicity is attached to a fixed structural element, and with an odd multiplicity - on the hook clip.

Depending on the number of rope branches attached to the drum of the lifting mechanism, single (simple) and double pulley hoists can be distinguished. In single pulley hoists, when winding or winding up a flexible element due to its movement along the axis of the drum, an undesirable change in the load on the drum supports is created. Also, if there are no free blocks in the system (the rope from the hook suspension block directly passes to the drum), the load moves not only in the vertical, but also in the horizontal plane.

To ensure strictly vertical lifting of the load, double pulleys (consisting of two single ones) are used; in this case, both ends of the rope are fixed to the drum. To ensure the normal position of the hook suspension in case of uneven stretching of the flexible element of both pulleys, a balancer or equalizing blocks are used. Such pulleys are used mainly in overhead and gantry cranes, as well as in heavy tower cranes, so that two standard cargo winches can be used instead of one large, high-power one, and also to obtain two or three speeds for lifting loads.

In power pulleys, when the multiplicity increases, it is possible to use ropes of reduced diameter, and as a result, reduce the diameter of the drum and blocks, reduce the weight and dimensions of the system as a whole. Increasing the multiplicity allows you to reduce the gear ratio, but at the same time requires a larger rope length and rope capacity of the drum.

High-speed pulleys differ from power pulleys in that in them the working force, usually developed by a hydraulic or pneumatic cylinder, is applied to a movable cage, and the load is suspended from the free end of a rope or chain. The gain in speed when using such a pulley is obtained as a result of increasing the height of the load.

When using pulleys, it should be taken into account that the elements used in the system are not absolutely flexible bodies, but have a certain rigidity, so the oncoming branch does not immediately fall into the stream of the block, and the running branch does not straighten out immediately. This is most noticeable when using steel ropes.

Homemade lifting devices are currently becoming increasingly popular. During construction and when working in a garage, you often have to move heavy loads. In construction, manual transportation takes considerable time, and it is not always possible to install ramps or scaffolding. In any case, it is much easier and more efficient to use lifts.

Crane diagram

The same applies to the automotive theme; a garage with a lift is much more convenient to use. The simplest lifts are an ordinary beam, rigidly fixed at one end, and a movable block is installed at the other end. A rope is thrown over the block, with the help of which the loads are tightened manually.

Such a homemade lift is quite simple to manufacture, but from a practical point of view it is very inconvenient. Firstly, the load is still lifted manually, and secondly, dismantling and installing a beam from one place to another takes even more time than simply dragging weights. Similar mechanisms are used in log houses.

Materials and tools:

• pillar supports;
• wooden top beam;
• metal guide;
• wheel-pulley;
• bearings;
• chain hoist;
• spacers;
• pulley;
• welding machine.

If the question of how to make a lift for a log house yourself makes you think, then here is a fairly simple solution. An upper beam with a length slightly greater than the length of the future structure is installed on 2 vertically dug pillar supports. This gap makes it possible to drag logs directly from the stack to the installation site.

The wooden beam must be equipped with a metal guide on top along which the mechanism will move. Further, the technology is simple: a wheel-pulley on a bearing is connected to an L-shaped metal part, to the other end of which a manual chain hoist with a load capacity of at least 750 kg is attached. This minimum is explained by the fact that the weight of a thirty-centimeter-wide log house ranges from 270 to 400 kg, depending on the moisture content of the wood.

The pillars for such a structure must be at least 20 cm in diameter, and the beam, based on the load, is a beam of at least 15X20 cm in cross section.

The guide is a piece of reinforcement to which the tips of the nails are welded at equal distances, no more than half a meter. They will attach the guide to the wooden beam.

The beam is fixed a couple of tens of cm away from the pillars to avoid coupling between the transport device and the pillar.

To strengthen the structure, spacers are installed on the nailed beam. If the height of the pillars is 4-5 m, then for stability they need to be dug into the ground 1 m and spacers installed on the side in which the beam shifts.

The pulley, preferably with sides, is put on the guide and the lift is ready for work.

Homemade crane

During individual construction, you cannot do without a crane, which can also be made with your own hands if necessary.

A homemade crane will help install floors, foundations and all other structural elements, thanks to its ability to fall below the zero mark by 2.5 m and rise to a height of about 2 m.

Such a crane allows you to transport cargo over a distance of 3 m. For home construction, the proposed capabilities should be sufficient.

This design does not provide a turning mechanism, since the crane is not designed for loads exceeding 300 kg and can be easily turned manually along with the entire structure.

In order to make a crane with your own hands, you will need:

• 4 telescopic pipes with an outer diameter of 140 mm,
• three-meter I-beam,
• metal corners for supporting structures,
• hoist or hand winch.

Homemade crane

Telescopic pipes are welded in pairs to the ends of the beams, consisting of two adjacent corners 1.5 and 0.5 m long, thus obtaining 2 U-shaped structures, which for stability are welded to the base by the beam and reinforced with triangular spacers.

Additional support corners are welded to the smaller frame, which will serve as the rear support of the crane, to prevent the future lifting device from tipping over.

An I-beam is welded in the center of the bottom of the horizontal beams so that the smaller frame is on the edge of the I-beam, and the larger one is a little further than 1.5 m from the smaller one.

A winch is attached to the bottom of the I-beam, which will be a horizontal mobile device, while the telescopic system will help move loads in the vertical direction.

Lift in the garage

How to make a homemade lift in the garage? Car enthusiasts quite often resort to self-repair of the vehicle, and removing a car engine manually is not an easy task.

For such purposes, it is simply necessary to have a garage lift, even one made by yourself. The collapsible crane beam system does not take up much space and is made from:

• cross pipe,
• square racks on triangular supports equipped with wheels,
• manual winch.

The pipe is inserted into fasteners welded to the top of the racks and secured with bolts. The winch is welded to the vertical post, and 2 rollers are welded to the beam, along which the cable from the winch moves. A winch for the garage is also easy to do with your own hands.

After use, the homemade crane beam is disassembled into 2 supports and a cross beam, which are placed in any corner of the garage. The advantage of such a beam crane is that its creation does not require special skills and materials; everything can be found at hand.

In addition, the beam crane will allow you to lift and transport loads of up to 800 kg within the garage.

Homemade winch for the garage. The design of the winch involves the presence of a drum with a cable, which is attached to a shaft to a frame made of square pipes. A large sprocket is attached to the outer edge of the drum, and a small sprocket is attached to the electric drive on a chain drive. If the winch is planned to be manual, then a handle is attached to the shaft on which the drum is mounted.

Car lift in the garage. To repair a car, a pit or overpass must be provided in the garage, but it is easier to organize a lift. Although this is a rather risky undertaking, equipping a lift in the garage with your own hands makes practical and economic sense.

The simplest car lift is the already described overhead crane with a winch; in this case, after lifting to the required height, the car is placed on platforms. But there is a risk of the cable breaking, so there is another garage lift.

To make a scissor lift you will need:

• channels from which the platform and base are made,

and for making scissors the following are suitable:

• I-beams,
• hydraulic cylinder,
• bushings,
• pump,
• distributor into two sections.

The beams are fastened with bushings using the scissor principle, and a hydraulic cylinder with a handle helps raise the scissors to the desired height.

Lifting machines are designed to help a person lift something heavy to a height. Most lifting mechanisms are based on a simple block system - a pulley system. He was already familiar to Archimedes, but now many people do not know about this brilliant invention. Remembering your physics course, find out how such a mechanism works, its structure and scope. Having understood the classification, you can begin to calculate. For everything to work out, here are instructions for constructing a simple model.

Block system - theory

The invention of the chain hoist gave a huge impetus to the development of civilizations. The block system helped build huge structures, many of which have survived to this day and puzzle modern builders. Shipbuilding also improved, and people were able to travel great distances. It's time to figure out what it is - a chain hoist and find out where it can be used today.

Simplicity and efficiency of the mechanism

Structure of the lifting mechanism

A classic chain hoist is a mechanism that consists of two main elements: a pulley; flexible connection

The simplest diagram: 1 – moving block, 2 – fixed, 3 – rope

A pulley is a metal wheel that has a special groove for a cable along its outer edge. An ordinary cable or rope can be used as a flexible connection. If the load is heavy enough, ropes made of synthetic fibers or steel ropes and even chains are used. To ensure that the pulley rotates easily, without jumping or jamming, roller bearings are used. All elements that move are lubricated.

One pulley is called a block. A pulley block is a system of blocks for lifting loads. The blocks in the lifting mechanism can be stationary (rigidly fixed) and movable (when the axis changes position during operation). One part of the pulley is attached to a fixed support, the other to the load. Movable rollers are located on the load side.

Fixed block

The role of the stationary block is to change the direction of movement of the rope and the action of the applied force. The role of the mobile is to gain strength.

Movable block

How it works - what's the secret?

The operating principle of a pulley block is similar to a lever: the force that needs to be applied becomes several times smaller, while the work is performed in the same volume. The role of the lever is played by the cable. In the operation of a chain hoist, the gain in strength is important, so the resulting loss in distance is not taken into account.

Depending on the design of the pulley, the gain in strength may vary. The simplest mechanism of two pulleys gives approximately a twofold gain, of three - threefold, and so on. The increase in distance is calculated using the same principle. To operate a simple pulley, you need a cable twice as long as the lifting height, and if you use a set of four blocks, then the length of the cable increases in direct proportion to four times.

Operating principle of the block system

In what areas is the block system used?

A chain hoist is a faithful assistant in a warehouse, in production, and in the transport sector. It is used wherever force needs to be used to move all kinds of loads. The system is widely used in construction.

Despite the fact that most of the heavy work is performed by construction equipment (cranes), the chain hoist has found a place in the design of load-handling mechanisms. The block system (pulley block) is a component of such lifting mechanisms as a winch, hoist, and construction equipment (various types of cranes, bulldozer, excavator).

In addition to the construction industry, pulleys are widely used in organizing rescue operations. The principle of operation remains the same, but the design is slightly modified. Rescue equipment is made of durable rope and carabiners are used. For devices of this purpose, it is important that the entire system is quickly assembled and does not require additional mechanisms.

Pulley hoist as part of a crane hook

Classification of models according to different characteristics

There are many executions of one idea - a system of blocks connected by rope. They are differentiated depending on the method of application and design features. Get to know the different types of lifts, find out what their purpose is and how the device differs.

Classification depending on the complexity of the mechanism

Depending on the complexity of the mechanism, simple ones are distinguished; complex; complex chain hoists.

Example of even models

A simple chain hoist is a system of series-connected rollers. All movable and fixed blocks, as well as the load itself, are combined by one cable. Even and odd simple pulleys are differentiated.

Even lifting mechanisms are those whose end of the cable is attached to a fixed support - a station. All combinations in this case will be considered even. And if the end of the rope is attached directly to the load or the place where the force is applied, this structure and all its derivatives will be called odd.

Odd chain hoist diagram

A complex pulley system can be called a pulley system. In this case, not individual blocks are connected in series, but entire combinations that can be used on their own. Roughly speaking, in this case one mechanism sets in motion another similar one.

Combining a two-fold and six-fold simple chain hoist gives a complex six-fold version

The complex chain hoist does not belong to one or the other type. Its distinctive feature is rollers moving towards the load. The complex model can include both simple and complex chain hoists.

Classification according to the purpose of the lift

Depending on what they want to get when using a chain hoist, they are divided into:

Power;

Express.

A – power version, B – high-speed

The power option is used more often. As the name suggests, its task is to ensure a gain in strength. Since significant gains require equally significant losses in distance, losses in speed are also inevitable. For example, for a 4:1 system, when lifting a load one meter, you need to pull 4 meters of cable, which slows down the work.

The high-speed chain hoist, by its principle, is a reverse power design. It does not give a gain in strength, its goal is speed. Used to speed up work at the expense of the applied effort.

Multiplicity is the main characteristic.

The main indicator that people pay attention to when organizing cargo lifting is the multiplicity of the pulley. This parameter conventionally indicates how many times the mechanism allows you to win in strength. In fact, the multiplicity shows how many branches of the rope the weight of the load is distributed over.

Kinematic ratio

The multiplicity is divided into kinematic (equal to the number of kinks in the rope) and force, which is calculated taking into account the cable’s overcoming the friction force and the non-ideal efficiency of the rollers. The reference books contain tables that display the dependence of the power factor on the kinematic factor at different block efficiencies.

As can be seen from the table, the force multiplicity differs significantly from the kinematic one. With a low roller efficiency (94%), the actual gain in strength of a 7:1 pulley will be less than the gain of a six-fold pulley with a block efficiency of 96%.

Schemes of pulleys of different multiplicities

How to make calculations for a chain hoist

Despite the fact that theoretically the design of a pulley hoist is extremely simple, in practice it is not always clear how to lift a load using blocks. How to understand what multiplicity is needed, how to find out the efficiency of the lift and each block separately. In order to find answers to these questions, you need to perform calculations.

Calculation of a separate block

The calculation of the chain hoist must be performed due to the fact that the working conditions are far from ideal. The mechanism is subject to frictional forces as a result of the movement of the cable along the pulley, as a result of the rotation of the roller itself, no matter what bearings are used.

In addition, flexible and pliable rope is rarely used on a construction site or as part of construction equipment. Steel rope or chain has much greater rigidity. Since bending such a cable when running against a block requires additional force, it must also be taken into account.

For the calculation, the moment equation for the pulley relative to the axis is derived:

SrunR = SrunR + q SrunR + Nfr (1)

Formula 1 shows the moments of such forces:

– Srun – force from the side of the escape rope;

– Srun – force from the oncoming rope;

– q Srun – force for bending/unbending the rope, taking into account its rigidity q;

– Nf – friction force in the block, taking into account the friction coefficient f.

To determine the moment, all forces are multiplied by the arm - the radius of the block R or the radius of the sleeve r.

The force of the approaching and escaping cable arises as a result of the interaction and friction of the rope threads. Since the force for bending/extension of the cable is significantly less than the others, when calculating the effect on the block axis, this value is often neglected:

N = 2 Srun×sinα (2)

In this equation:

– N – impact on the pulley axis;

– Srun – force from the oncoming rope (taken to be approximately equal to Srun;

– α – angle of deviation from the axis.

Pull block block

Calculation of the useful action of the block

As you know, efficiency is the efficiency factor, that is, how effective the work performed was. It is calculated as the ratio of work completed and work expended. In the case of a pulley block, the formula is applied:

ηb = Srun/ Srun = 1/(1 + q + 2fsinα×d/D) (3)

In the equation:

– 3 ηb – block efficiency;

– d and D – respectively, the diameter of the bushing and the pulley itself;

– q – rigidity coefficient of flexible connection (rope); f – friction coefficient;

– α – angle of deviation from the axis.

From this formula it can be seen that the efficiency is affected by the structure of the block (through the f coefficient), its size (through the d/D ratio) and the rope material (q coefficient). The maximum efficiency value can be achieved using bronze bushings and rolling bearings (up to 98%). Sliding bearings will provide up to 96% efficiency.

The diagram shows all the forces S on different branches of the rope

The lifting mechanism consists of several blocks. The total efficiency of a pulley block is not equal to the arithmetic sum of all individual components. For the calculation, they use a much more complex formula, or rather, a system of equations, where all forces are expressed through the value of the primary S0 and the efficiency of the mechanism:

– S1=ηп S0;

– S2=(ηп)2 S0; (–4)

S3=(ηп)3 S0; ….

– Sn=(ηп)n S0.

Efficiency of a chain hoist at different magnifications

Since the efficiency value is always less than 1, with each new block and equation in the system, the value of Sn will rapidly decrease. The total efficiency of the pulley will depend not only on ηb, but also on the number of these blocks - the multiplicity of the system. Using the table, you can find ηp for systems with different numbers of blocks at different efficiency values ​​of each.

How to make a lift with your own hands

In construction, during installation work, it is not always possible to fit a crane. Then the question arises of how to lift the load with a rope. And here a simple chain hoist finds its application. To make it and fully operate, you need to make calculations, drawings, and choose the right rope and blocks.

Different schemes of simple and complex lifts

Preparation of the base - diagram and drawing

Before you start building a chain hoist with your own hands, you need to carefully study the drawings and choose a suitable scheme for yourself. You should rely on how it will be more convenient for you to place the structure, what blocks and cable are available.

It happens that the lifting capacity of the pulley blocks is not enough, and there is no time or opportunity to build a complex multiple lifting mechanism. Then double chain hoists are used, which are a combination of two single ones. This device can also lift the load so that it moves strictly vertically, without distortions.

Drawings of a dual model in different variations

How to choose a rope and block

The most important role in building a chain hoist with your own hands is played by the rope. It is important that it does not stretch. Such ropes are called static. Stretching and deformation of a flexible connection causes serious losses in work efficiency. For a homemade mechanism, a synthetic cable is suitable; the thickness depends on the weight of the load.

The material and quality of the blocks are indicators that will provide homemade lifting devices with the calculated load capacity. Depending on the bearings that are installed in the block, its efficiency changes and this is already taken into account in the calculations.

But how can you lift a load to a height with your own hands and not drop it? To protect the load from possible reverse movement, you can install a special locking block that allows the rope to move only in one direction - the desired direction.

Roller along which the rope moves

Step-by-step instructions for lifting a load through a block

When the rope and blocks are ready, the diagram has been selected, and the calculations have been made, you can begin assembly. For a simple double pulley you will need:

– roller – 2 pcs.;

– bearings;

– bushing – 2 pcs.;

– clip for the block – 2 pcs.;

- rope; hook for hanging cargo;

– slings – if they are needed for installation.

Carabiners are used for quick connection

Step-by-step lifting of the load to a height is carried out as follows:

1. Connect the rollers, bushing and bearings. They combine it all into a clip. Get a block.

2. The rope is launched into the first block;

3. The frame with this block is rigidly attached to a fixed support (reinforced concrete beam, pillar, wall, specially mounted extension, etc.);

4. Then the end of the rope is passed through the second block (movable).

5. A hook is attached to the clip.

6. The free end of the rope is fixed.

7. Sling the load being lifted and connect it to the pulley.

The homemade lifting mechanism is ready to use and will provide double the strength benefits. Now, to raise the load to a height, just pull the end of the rope. By bending around both rollers, the rope will lift the load without much effort.

Is it possible to combine a chain hoist and a winch?

If you attach an electric winch to the homemade mechanism that you build according to these instructions, you will get a real do-it-yourself crane. Now you don’t have to strain at all to lift the load; the winch will do everything for you.

Even a manual winch will make lifting the load more comfortable - you don’t need to rub your hands on the rope and worry about the rope slipping out of your hands. In any case, turning the winch handle is much easier.

Pulley hoist for winch

In principle, even outside a construction site, the ability to build a basic pulley for a winch in field conditions with a minimum of tools and materials is a very useful skill. It will be especially appreciated by motorists who are lucky enough to get their car stuck somewhere in an impassable place. A hastily made pulley will significantly increase the performance of the winch.

It is difficult to overestimate the importance of pulley hoists in the development of modern construction and mechanical engineering. Everyone should understand the principle of operation and visually imagine its design. Now you are not afraid of situations when you need to lift a load, but there is no special equipment. A few pulleys, a rope and ingenuity will allow you to do this without using a crane.

When building a house from aerated concrete, timber, brick, etc. There is often a need to lift a load. For example, you need to “throw” blocks or wooden beams onto the second floor, lift bags of cement, or pour an armored belt. Doing this manually, even with the help of assistants, is not so easy - health is more expensive. Hiring a truck crane or manipulator for a small amount of work is expensive. The solution is to use a mini-crane, which, to reduce the cost of construction, is made by hand.

• How to make a lift for laying aerated concrete.
• What parts and tools are needed to build a mini crane.
• How to reduce the costs of building a universal lift.

Lift for laying aerated concrete blocks

Abroad, during the construction of private houses, cranes and various lifts are often used. This way construction goes faster, which means the “box” is cheaper, because It is more profitable to use small-scale mechanization tools than to hire laborers. Our developer relies on himself and often builds a house “with one helmet.” Therefore, the urgent question is how not to physically overstrain yourself when laying a wall from aerated concrete blocks weighing 35-40 kg.

An interesting variant of an unusual homemade “assistant” of the FORUMHOUSE user with the nickname Cross. First, let's show what he took as a basis.

German mini crane with retractable central post

A special feature of the lift is the original folding “arm-boom”, with the help of which the crane, moving on wheels, can reach two opposite walls.

Cross

I am building a house myself and, in order to be able to lay aerated concrete blocks, I built a lift according to the above model. The crane was made completely collapsible, except for the base. I didn’t measure the maximum load on the hook, but it easily lifts me (weighing 95 kg).

Technical characteristics of the lift:

• width – 2200 mm;
• height – 4200 mm;
• boom radius – 4200 mm;
• load capacity of electric hoist – up to 800 kg;
• total weight of the crane with ballast is approximately 650 kg;
• lift weight without ballast – about 300 kg;
• The maximum lifting height of the masonry block is 3500 mm.

The working height of lifting blocks is adjustable in two ranges. The first is 1750 mm. The second is 3.5 m, for which the structure is raised, sliding upward along the supporting “legs” using a hydraulic jack lined with spacers made of GB blocks.

To make the lift, the user needed:

• swivel wheels;
• profile pipes for the mast, “legs” and boom with a section of 12x12 cm, 12x6 cm, wall 6 mm;
• pipe-jibs – 63x3 mm;
• powerful gate hinges;
• The boom rotating mechanism is made of ST45 steel and “205” bearings.

During operation, the design was modified. For example, the user laid the cable for the winch in a corrugated pipe and extended the cable for the control panel.

Cross

The design has a number of shortcomings that I would like to correct. For example, I’m thinking about making wireless control, replacing the gate hinges with bearings. Increase the number of “joints” in the boom at the same reach. Instead of a temporary counterweight - bags of sand concrete, pour concrete ballast.

Important nuance: in order for the lift to move around the construction site or, for example, over the concrete slab of the second floor, it is necessary to keep the workplace clean, because GB fragments and debris interfere with the relocation of the tap.

The design of the unusual lift attracted the interest of portal users.

Konstantin Y. Member of FORUMHOUSE

With such a lift, I think, as they do in Germany, you need to make masonry from blocks larger than standard ones. The length and height are 2-3 times greater than a regular GB. The crane has enough lifting capacity, and the laying speed will increase significantly.

According to Cross, he heard that someone on the portal had already tried to order blocks of 1x0.4x0.6 m format from a gas silicate manufacturer. But it turned out that this was not profitable for the plant, because it is necessary to reconfigure the line for the production of GB, but for the sake of a small volume (for an ordinary private house) they will not do this.

Vegaroma FORUMHOUSE Member

I'm wondering: is the work on site easier when using a crane? What work can be done with it and what cannot?

Cross

There is no need to install scaffolding when laying GB walls. The lift can be assembled and disassembled. I poured the concrete lintels over the windows the old fashioned way, from buckets, because... The volume is small, and it’s easier to do it with one assistant.

Grand total: The mini-crane turned out to be successful, and with some modifications to its design, the lift can be put into small-scale production.

Mini crane made from scrap metal

Another version of a lifting mechanism made of metal “lying under your feet” was made by a portal participant with the nickname Peter_1.

According to Peter_1, The reason for building a crane is that the house is getting higher and higher, and the blocks and concrete are getting heavier. Therefore, after revising the “unnecessary things”, the user manufactured a completely dismountable crane with a lifting capacity of 200 kg.

Peter_1

I think my crane can lift more, but I didn’t overload it. The crane can be disassembled into parts weighing 30-60 kg and can be easily transported in a car trailer. I carry an arrow on the trunk. Statically tested a structure weighing 400 kg. I usually lift up to 150 kg. This is quite enough for my construction needs.

At one time, the crane, with a boom reach of 5 m, lifts 10 blocks weighing 15 kg each, or four 15-liter buckets of solution.

The design of the crane is a hodgepodge of what was at hand. Let's list the main details:

• swivel unit - truck hub;

Hubs from cars, trucks, and farm equipment are often used to make the swivel assembly in homemade cranes. The main thing is to calculate the loads acting on it and the fasteners.

• the boom is made of a pipe with a diameter of 75 mm;

• outriggers and base - a rectangular pipe with a section of 8x5 and 8.5x5.5 cm;

• the base of the tower is the “200th” channel;

• worm gearboxes for boom and cargo winches.

• three-phase electric motor with reverse, power 0.9 kW, converted to power from a 220 V network;

The crane turned out to be mobile, and by lowering the boom, it can be moved from place to place, rolling on wheels along compacted soil. Level adjustment is carried out using screw supports.

Metal, gearboxes and rollers were purchased at a recycled metal shop. Only the cable and bearings are new.

The weight of the crane without counterweight is about 250 kg. The cost of the structure, taking into account the purchase of consumables - cutting discs for angle grinders, electrodes for a welding inverter and paint, is 4 thousand rubles.

Peter_1

Crane, + time for turning, + selection of components and fitting of components, I completed it in 3 working days. In the future, after finishing the work, I will completely disassemble it.

Inexpensive mini lift

Practice shows that when building a private house, a real crane is not always needed. Often, a developer can get by with “little expense” and make a small lift based on an electrically driven hoist.

Gexx FORUMHOUSE Member

My design is simpler than the authors above, but it suits me quite well. I bought a hoist with a load capacity of 300 kg without a block and 600 kg with a block. Tests have shown that the device can lift a load weighing 250-270 kg, then the engine protection is triggered. During the construction season, I used it to lift about 40 pallets with building blocks, a 6-meter beam for the mauerlat, rafters, mortar for masonry and concrete for the reinforced belt.

The lift, again to save money, is made from used pipes, angles and channels.