Do-it-yourself Makita 2450 Punch Repair Instruction

2023 Author: Philip Bishop | [email protected]. Last modified: 2023-08-25 07:54

• Procedure for determining electrical faults
• Makita Rotary Hammer Reverse Switch Repair
• Repair of the contact between the stator and the reverse switch

Hammer drills are percussion drilling devices designed for drilling and chiselling holes in extra strong materials.

The hammer drill implements two ideas: the working tool rotates and simultaneously moves in the longitudinal direction, creating a shock impulse.

Rock drills always work under extreme conditions.

The duration of the hammer drill depends not only on the correct operating conditions, but also on the reliability of the parts included in the product.

But no matter how hard you try, over time, punches start to fail.

To properly repair a punch, you need to familiarize yourself with its device.

Do-it-yourself repair of the Makita 2470 and 2450 perforator can be done by a person who has the skills of a locksmith and knows the basics of electrical engineering.

Remember! Observe safety regulations and unplug the punch from the mains when disassembling.

Hammer drills Makita 2450 and 2470 are assembled in almost the same scheme and from the same parts. Repairing them is no different.

For the convenience of repair, below is an assembly diagram and a catalog of parts for Makita perforators.

The scheme of the Makita 2450 and 2470 puncher consists of a mechanical and electrical part.

The mechanical part provides the transmission of torque to the drill bit, while simultaneously creating a translational movement that creates a shock.

The mechanical part consists of a rotation drive and an impact mechanism.

The electrical circuit of the Makita perforator provides the conversion of electrical energy into kinetic energy through the rotation of the rotor. The electrical part includes an electric motor, a power button with a speed controller, a reverse switch, and connecting wires.

The main malfunctions of the makita rotary hammer

Malfunctions of rotary hammers are divided into electrical and mechanical.

In this article, we will consider all the malfunctions of the electrical part of the Makita 2470 and 2450 rock drills and how to fix them:

Electrical malfunctions of Makita 2450 and Makita 2470 rotary hammers

Electrical malfunctions are manifested in the fact that when the rotary hammer is connected to the voltage network, the tool does not turn on.

The scheme for connecting the Makita puncher to the network is simple.

The electrical diagram of the Makita 2450 perforator is a serial connection of the electric motor, start button and wires. The Makita 2470 hammer drill is similar.

Through the connecting cord, pos. 72, the supply voltage of 220 V is supplied through the switch, pos. 68, and electric brushes through the brush holder, pos. 66, to the rotor lamellas of the electric motor, pos. 54, and through the contacts of the reverse switch, pos. 60, to the stator winding, pos. 59.

The most common malfunction is the lack of contacts in the connections.

Procedure for determining electrical faults

Video:

Determination of the integrity of the electrical part of the Makita perforator. In order to repair the Makita 2450 or Makita 2470 hammer drill with your own hands, you need to arm yourself with devices and tools. Any tester, screwdriver set, wrenches, hammer, wooden guide will do. It is good to have a screwdriver with a built-in phase indicator.

You need to take the tester, connect to the ends of the punch plug and press the punch switch. If the tester shows some resistance, then the power circuit of the puncher is intact.

If the tester shows infinity, then the continuity of the circuit is broken and you need to remove the back cover to check the connecting cable and electric brushes of the hammer drill.

The back cover (usually black) of the punch is easy to remove, you just need to unscrew three screws with a screwdriver or screwdriver.

Remove the cover and use a screwdriver to disconnect the ends of the wires from the electric brushes.

Using a tester or a home-made device, popularly called "arkashka", determine the integrity of the lead wires and the correct operation of the switch.

A few words about a simple control device called "arkashka". The device consists of an LED or a light bulb from a flashlight, a penlight battery and two pieces of wire. The entire electrical circuit of the control device is a series-connected parts. Connect the battery to one end of the LED or light bulb, and connect the wires to the free ends of the LED and battery. You will have a universal device for checking the continuity of electrical circuits.

Typical malfunctions of the Makita 2450 and 2470 rotary hammer

Frequent faults in the electrical part of the Makita 2450 and Makita 2470 rotary hammer:

• break of the supply cable at the point of entry into the perforator;
• failure of the button of the TG813TLB-1 switch, art.650508-0, pos.68.;
• wear of electric carbon brushes SV-419, art.191962-4, pos.65;
• wear of the reverse switch contacts;
• wear of the rotor bearings: bearing 609LLU, art.210060-6, item 51; bearing 607LLU, item 211021-9, item 56;
• short circuit of the rotor 220-240 V, art.515668-8, pos. 54;
• failure of the stator winding 220-240 V for HR2450, art. 633488-5, pos. 59.

The switch TG813TLB-1, art.650508-0 is used as a start button; pos. 68.

Replacement of brushes is carried out when they are completely abraded or poor contact. This malfunction is detected by strong heating of the points of the installation points of the electric brushes.

Failure to turn on the hammer drill can be caused by abrasion of the contacts on the reverse switch.

Eliminating such a malfunction is very simple.

Makita Rotary Hammer Reverse Switch Repair

To repair the reverse switch, the rear cover must be detached. Disconnect the wires carefully from the button. Inspect the switch carefully.

Further disassembly consists in removing the brush holder, having previously released the brushes themselves.

After removing the brush holder, you will reach the contacts of the reverse switch.

Determine its condition, replace contacts if necessary.

Another common electrical fault is poor contact between the stator and the lower contacts of the reversing switch.

Repair of the contact between the stator and the reverse switch

To remove the stator, the gear housing (black) must be disconnected from the stator housing (green).

Remember! In the mechanical part of the rotor, the bearing is pressed by a special ring. Do not lose it when disassembling.

The stator is located in the green housing. Looking into the middle, you will see two self-tapping screws 4 × 60, ref. 266334-3, item 57, securing the stator to the housing. Unscrew them, remove the plastic stator protection for HR2450, art.419201-3, pos.58., Free the stator.

When you take out the stator, you will see the contacts on the stator and the reversing switch panel.

Carefully clean the contacts with emery paper, treat with solvent or alcohol.

Before assembly, bend the contacts so that they fit snugly into each other. Lubricate the contacts with a thin layer of petroleum jelly.

The electrical part of the rock drill is assembled in the reverse order.