In the large nomenclature of technological operations that an actively practicing home craftsman has to perform in his workshop, there will definitely be a place for work related to the pressing of various parts and materials.
A jack press is needed to remove or install automotive bearings, press out / press in different sleeves or crankshaft, as well as compressing metal parts.
To "close" this problem once and for all, you can, of course, buy a press made by a well-known manufacturer. But you can ask, for example, the question of how to make a press out of a jack. After all, the debugged specialized equipment assembled by industrial means is not always affordable for the average buyer. In addition, it is not always able to arrange the master with its parameters or dimensions, which have to be especially taken into account by the owners of relatively small workshops.
Nevertheless, to solve problems associated, for example, with the removal or installation of automotive bearings, pressing out / pressing in various bushings or crankshaft, compressing various metal parts or bending reinforcement (pipes), is necessary. The way out of this situation can be skillful hands and the idea to make a press from a jack.
Features of the hydraulic jack, its pros and cons
Diagram of the hydraulic jack.
The choice of a hydraulic jack as the basis for mounting a power press is not accidental. The main feature of this device, which makes it the core of an improvised installation for various compression operations, is the direct use of fundamental physical laws in it. In accordance with these laws, a liquid, unlike a gas, is not compressed under pressure and does not decrease in its volume.
Due to this property, the jacks are adequate, without loss of power, affect the object being processed by the force, which the operator transmits to the specified lifts. Moreover, the force of pressure that the jack exerts on the material through the stops far exceeds the force applied by man, which makes this device very useful in many technical areas.
The design of the hydraulic press.
In particular, hydraulic jacks show a very high efficiency - up to 80%. This allows you to count on an excellent load capacity, and in the case of a homemade press - on a significant force of compression. Such an impressive effect is provided by a large gear ratio between the cross sections of the cylinder and the pump plunger jack.
With all these advantages, this lifting device also has its drawbacks, which have to be taken into account when you undertake to make a press from a jack. The most significant of these is that it is impossible to precisely adjust the stem lowering height in the jack. In our case, when it is used not for lifting a load, but for pressure on the workpiece being processed, this leads to the fact that every time after such an impact the pressure in the chamber has to be relieved to zero, then to repeat the entire stroke of the rod until the moment of working contact stops pressed billet.Back to table of contents
Which jack is best for press equipment?
Based on a fairly simple internal layout and the shape of the hull, of all types of hydraulic lifts, the single-rod bottle jack is the most suitable for assembling a homemade press.
In contrast to mechanical (lever, crank, screw, eccentric) presses, devices for power compression based on a bottle hydraulic jack have significantly more power.
A single rod jack can lift weights from 2 to 100 tons.
According to calculations, such jacks, depending on their design, are capable of lifting weight (exerting force) in a wide range from 2 to 100 tons, which is very important when used as a power unit of a press.
It is also necessary to note the comparative (with respect to other types of jacks) compactness of the bottle version. Accordingly, this factor contributes to the design of a generally sufficiently small presses, suitable for use in a limited space of a home workshop or a private garage.Back to table of contents
Materials and tools for the manufacture of hydraulic devices
To successfully assemble this device, you should prepare the following materials and tools:
- hydraulic bottle jack (in a small private workshop or garage it is usually enough to have a device with a force of up to 10 tons);
- welding machine;
- a set of electrodes;
- angle grinder (Bulgarian) with a disk for cutting metal;
- channel (from No. 8 and above) up to 4 m long;
- profiled thick-walled tube of rectangular (square) section;
- metal corner 50x50 mm;
- steel strip (thickness - not less than 10 mm);
- a piece of pipe of suitable diameter for the head of the jacking rod (length - 10-15 mm);
- metal plate 25x10 cm (thickness - 9-10 mm);
- 2 springs for pulling the stop (from car seats, door, etc.).
The assembly procedure do-it-yourself hydraulic press
Getting to the assembly of this device, it should be borne in mind that it is not only the presence of a good jack, but also the manufacture of a reliable support platform for it. After all, the same amount of force will press on the “frame” as it is on the object being processed. Therefore, the platform itself must be very strong, with a large margin of this strength, otherwise the whole structure may fall apart.
Tools for making hydraulic press.
This quality is ensured by the use in the manufacture of the platform of thick metal profiles (channels) with the maximum possible number of ribs. You can take a steel profile of a square or rectangular configuration. It is necessary to prepare 4 profiles of suitable length.
Then the profiles are welded to each other by side walls with careful welding of seams from above and below. This will give the base of the press additional rigidity.
We turn to the manufacture of vertical pillars and lower stops. For all these structural elements, a profiled tube is used. The height of the racks is calculated as the sum of the maximum output of the rod, the height of the body of the bottle jack and the thickness that the removable stop has. At the same time, the length of the bottom stop should be equal to the length of the support platform.
The platform, both pillars and the bottom stop of the future press are welded into one rectangular frame. It is necessary to take measures so that its structure is assembled strictly at right angles. For this purpose, you can use metal corners. The additional strength of the whole structure will be given by metal plates, welded both diagonally to the support platform and side posts.
Drawing hydraulic press.
In the next step, we make a removable support, which will move vertically with the help of guides and create pressure on the workpiece. For its manufacture, it will be necessary how much strips of steel with a length slightly less than the distance between the posts and a thickness of at least 10 mm. All strips must be welded to each other on both sides.
Since it is necessary to process objects of different shape in the hydraulic press, this support should be removed freely. For this, as well as for fixing the stop during its movement along the vertical racks, two through holes are drilled in a block of steel strips. In addition, two steel plates are prepared with a length of 100 mm longer than the length of the block itself. Two holes are drilled in these plates, which should be coaxial with the holes made in the block.
To install a removable stop on the press frame, steel plates are attached to the unit with bolts and nuts with washers of suitable sizes. These plates as a result of proper installation should be located on both sides of the racks, limiting the free lateral course of the removable stop.
To make a removable stop, you can still take a segment of the same thick-walled rectangular (square) pipe, which was used to assemble the base of the press. The length of this segment is chosen slightly less than the distance between the racks. To it in the same way as described above, with the help of bolts and nuts, two guide steel plates are attached to the sides.
The assembly scheme of the hydraulic press.
On the lower plane of the support platform, strictly in the center of its length, a length of pipe of 10-15 mm is welded. Its diameter must be such that the upper end of the ram rod can be inserted into it without special efforts. In the future, this piece of pipe will play the role of a lock position of the power unit.
After that, at an equal distance from the specified fragment of the pipe-clamp between the support platform and the removable stop, springs are attached in an arbitrary way. Stretching when the stem is extended, when pressure is relieved, they will return the stop block to its original upper position.
At the final stage of installation of the power device install the actual jack. For this, it is necessary with the help of additional devices to delay the moving support. The jack is inserted between the platform and the stop so that the end of the rod in the retracted position is inserted into the retainer.
Further, the base of the jack is bolted or welded to the movable stop. Moreover, the first option is preferable, because it allows the master, if necessary, to remove the lift from a home-made press and apply it for another purpose.
At this press can be considered ready for use.Back to table of contents
How to make a press with additional settings?
Sometimes, when operating a hydraulic press, there is a need to somewhat shorten the free stroke of the jack rod. To achieve this, it is recommended to reduce the distance between the removable stop moving downwards along the side racks and the lower stop.
For this purpose, an additional - transitional - metal profile of square or rectangular section is established. Often its production is the same thick-walled profile, which is used for the manufacture of racks and lower stops.
The hydraulic press is assembled from scrap metal and a car jack.
Its length is determined by the distance between the side posts of the press. A fragment of a rectangular profile is arbitrarily attached to the frame, it can be either fixed (welded by welding) or interchangeable (fixed by means of screws or bolts).
Another adjustment method involves the creation of an additional movable lower stop. To install it in the side racks of the frame at the right height for the master, the holes are drilled directly opposite each other. Movable stop, the length of which should be slightly less than the distance between the uprights, is attached to them with bolts and nuts.
In addition, the use of a different size and configuration of interchangeable linings or anvils will help to make a press with a reduced distance between the stops. The methods described, used individually or in combination, will significantly reduce the period of supplying the movable support to the workpiece and thereby accelerate the start of the compression process and reduce the overall time for the work task.Back to table of contents
Possible malfunctions and maintenance of the jack
Meanwhile, making a press with a jack is not enough. It is necessary to know how to further maintain this device and eliminate defects. The most frequent malfunctions of the jack include the flow of oil and the penetration of air into its working chamber.
The resulting oil indicates, as a rule, the failure of glands and various seals. This defect is eliminated by replacing defective seals with an appropriate repair kit. To do this, the jack is disassembled, pistons and rod are removed from the housing, then they are checked for corrosion, pollution and deformations. Dirt is removed, when a noticeable bend of the rod is detected, the defective element is replaced with a new one.
The design of the finished hydraulic press.
The bypass valve is also examined for deformation and contamination. In case of mechanical deformations, the damaged valve is replaced with a new one, while the blocked valve can be cleaned of dirt.
After that, the old oil is drained from the jack cylinders. You can speed up the process by pumping the system up and down with a lever. Instead of old oil, a new working fluid is poured, but only after the installation of a new repair kit.
As a result of the prolonged use of such a press, air bubbles may accumulate in the working chamber of the jack, which significantly reduce the efficiency of the entire device. In this case, the jack is either not functioning at all, or its stock is moving too slowly.
Air bubbles are removed by accelerated pumping of the jack pump when the oil tank plug and the relief valve are open. As a result of vigorous movements, the air from the working chamber of the lifting device will flow into the oil tank. After that, the plug of the oil tank and the overflow valve should be tightly closed.
If everything was done correctly, the jack will work again normally. If the fault does not disappear after the first time, the described pumping will need to be repeated.
Thus, it is possible to assemble a small press by yourself, using a standard car jack and ancillary tools and materials. Moreover, if you carefully examine the properties of materials and the order of its assembly, it will be quite easy to do.