How to make a reverse hammer for a spotter

Functionality of spotters of standard models

Spotters that are mass-produced in production environments have a number of sought-after features. Among them:

  • Ability to weld repair washers;
  • welding a metal electrode followed by pulling the metal of the part;
  • The use of the machine complete with graphite electrodes, which allow you to perform metal precipitation (heating and then cooling);
  • easy maintenance, easy operation;
  • two modes for welding works. permanent switching on (this mode uses carbon electrode) and short-time switching that can be adjusted in time (this mode is used for welding of repair washers or metal electrode);
  • equipped with a forced cooling system (the machine design also includes a thermostat whose function is to turn off the spotter when it overheats, and turn it on when it cools to the desired temperature).

One of the variations of the factory-made spotters and their various accessories

Equipment features

The spotter is a device that has changed all previous ideas about the principle of removing dents. Its application helps to eliminate defects on the outside of the vehicle surface.

The use of the equipment is a kind of welding machine, which involves the ability to work with a variety of metals.

The design of the device can have several different attachments, as well as modes of operation. Its working elements can be called:

The basis of the spotter is an inverter welding machine, like a microwave, which is capable of delivering two types of current:

According to the type of movement, the equipment can be of two types:

  • compact. have a small size, which makes it possible to carry them in the hands through the use of a convenient handle. These machines can be classified as non-professional;
  • Portable. this is professional equipment, for the movement of which a special stand with wheels is used.

On the front of the body there is a panel, which is used for setting and adjusting the working process. Regardless of the model of the spotter, the master has the ability to set the necessary level of power and current of the device. A toggle switch with possible operating modes indicated on it is located on the panel for this purpose.

The welding process is carried out as a result of the electrical circuit being closed. In doing so, the master fixes the mass on the surface of the vehicle’s body. It is also necessary to remove the battery from the machine beforehand.

The gun is equipped with a trigger, which, when lowered, closes the electric circuit and thus provides the current flow.

The choice of the nozzle that is inserted at the end of the gun depends on the type of surgery being performed. The current heats the worktop and after a short time the surface melts. The area is small, but sufficient to be able to repair the existing defect. The surface is not overheated.

The purpose of the spotter and its features

Homemade spotter is used for auto bodywork. This is done when, for some reason, it is not possible to align the surface of the part from the inside. You can locally heat the metal with the specified tool, if there are small damages on the body area. It is important to understand how to make a spotter with your own hands to get a quality and functional product.

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Welding process looks like this. On the place of the damaged metal is fixed fasteners. The device is connected to it and with the help of auxiliary devices or with your own hands pull out dents. The body repair tool allows you to quickly and efficiently repair the car without painting the damaged area. The spotter is good because its operation allows you to control the function of each part. This is due to the fact that the probability of overheating and wire breakage is quite high.

Spot welding on the basis of an inverter

Contact welding from an inverter, made with your own hands, is the most common type of homemade spotter for straightening. There are many ways of assembling this device.

This kind of spotter is very similar to contact welding and is its modification. But its design has a distinctive feature. it does not have clamps. That is why it can be considered an analog of arc welding, in which the current passes through the car body. One welding contact is connected to the surface, and the second contact is the nozzle and the rod.

Inverter device

The main part of the device is a gun, which can be made from a similar device for construction glue or from a semi-automatic welding. Many people wonder how to assemble a puller with their own hands. The circuit is quite simple.

It includes the following elements:

In order to assemble it, you will need the following parts:

    200 volt thyristor;

  • Transformer, which regulates the voltage and lowers it to 12 volts;
  • Relay (30 amps);
  • diode bridge;
  • contact group;
  • control button.

The transformer is connected to the mains using a diode bridge, and the thyristor is connected to the bridge.

make, reverse, hammer, spotter

The spotter works according to the following algorithm:

    The power button is pressed, the capacitor and for a short time the thyristor and resistor are started;

  • subsequently, using diodes, voltage is applied to the transformer winding;
  • further the electrode (guide) is welded to the surface of the car;
  • when the capacitor discharges, the thyristor closes and the transformer loses current;
  • the apparatus is completed and only the capacitor continues to be charged by the transformer for further operation.

Alternatively, thyristors and diode bridge are replaced by triacs. The design of the homemade spotter must be carefully calculated for its proper operation. It must work without interruption, even with minimal investment.

Materials needed for operation

You need up to 40 cubic centimeters of metal to assemble the machine. At the perimeter of the thyristor overheating rarely occurs, most often it occurs after the cable. The spindle of the device can also get very hot, so it is desirable to make it of brass.

The cable of the apparatus should have a cross section of 70 kV. millimeters, and for the length of the hammer it is enough 2 meters. It is also necessary to arrange the pulse control.

First you should wind the secondary winding of the transformer together with the copper busbar. It can also be made of aluminum. After that, it is necessary to wind two more layers of winding. The result should be a winding of 250 square millimeters (5 windings with six coils).

It is also necessary to pay great attention to the outside of the hammer (electrode). As a rule, a construction glue gun is used as a handle, and the wire for it requires thermal insulation. It should also be taken into account that the insulation winding will shrink during operation.

What you need to make a spotter

You can assemble the entire unit yourself, or make it from a battery or welding machine.

See also  How to make a reverse hammer with their own hands

To make a spotter from scratch you need to have:

make, reverse, hammer, spotter
  • Transformer for 1500 A
  • Reverse hammer. using a metal billet, the axis is made of brass (M10), welded to its end a sharp tip for spot welding
  • Gun. a device is made for clamping the backhammer on one side and connecting the cable on the other side, the inclusion is regulated by a button
  • Control unit. it contains thyristor (200 V), diode bridge, 12-volt step-down transformer, relay (30 A), a contractor (220 V). to assemble the device the scheme of the spotter is used
  • Thick wires are for ground and gun
  • Clip for the ground wire

Under the machine is made the case, which is better to make on the wheels.

BP unit

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As it becomes clear, it is the BP that guides the bendix into engagement with the flywheel crown. The whole cycle is based on the principles of electromagnetism.

The BP design includes the housing, armature, magnetic coil, contacts and spring.

The armature sits inside a hollow tube (core). The armature winding is the coils in the form of wires. It enters the tube after the electromagnetic field has been built up in the bobbin. If the current stops flowing the armature will run unimpeded.

The magnet inside the VR is a pair of coils. One of these acts as a retracting element, the other is purely a holding function. The first retracting coil is connected directly to the electric motor and the control pin, and the second, holding coil, is integrated with the fuselage and the control pin.

It is clear that the magnetic field occurs in the coil after an impulse is received at the control terminal from the battery. As mentioned above, the armature begins its work, compresses the spring and at the same moment the bendix is pushed out, which enters into engagement with the flywheel crown.

Обратный молоток из старых амортизаторов своими руками. / Reverse hammer of wear shock absorbers

After starting the engine, the power to the starter stops, the armature returns to the initial exposure by the spring action. contacts open, the bendix disengages from the flywheel.

Is it possible to make a spotter with the factory specifications

If you correctly calculate the parameters, choose the right components and properly manufacture not only the power supply, but also the tool accessories, then the home-made spotter by its functionality will not differ from its factory one. With some amateur radio skills, the power supply and the necessary wires are easy to make with your own hands. As a welding gun, you can use any product of suitable shape, the design of which would allow to strengthen the threaded contacts on its ends and would be convenient to work.

For the gun and reverse hammer, you need a few parts which are best turned on a lathe. Part of the electrode-tips can be made by hand using ordinary locksmith’s tools, but some are still better to order or purchase ready-made. In order to work with a homemade machine, you may need additional devices (pullers, combs, rods), which can also be made by yourself. Consumables for the spotter (welding washers, pins, wavy wire, carbon electrodes, etc.).) are inexpensive and can be easily purchased at specialized stores.

The design and purpose of the device

Spotter is a machine that is used for spot welding. The construction consists of such parts as:

  • Magnet wire;
  • sharpened electrode;
  • insulated primary winding;
  • secondary winding;
  • cooling fan.

Popular with auto body repairers. Applicable for leveling various dents on the metal body.

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In the process of action, the unit produces a discharge that heats the metal. They are welded at the points of contact.

The heating and cooling process is very fast. Oxidation and metal reactions are avoided. No marks are left behind after welding. They are smoothed by means of an angle grinder. No need for special materials. welding electrodes, wire, etc. д.

No dismantling of the door or fender is required. Work can be carried out on the outer appearance of the trim. Additional advantage. easy operation in areas with difficult access.

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