Dismantling the Makita 2450 Hammer Barrel
Independent repair of the Makita hammer drill barrel with a selection of spare parts
Even very reliable Makita rotary hammers break down over time. Any breakdown is eliminated, you only need to have straight arms and perseverance. In addition to electrical malfunctions, rotary hammers are also subject to mechanical damage.
The work of rock drills with solid materials in a dusty environment shortens the life of the machine and requires user intervention to perform preventive maintenance.
Repair of the mechanical part of the Makita 2450 and 2470 puncher
Any repair of the tool begins with the determination of the nature of the malfunction and disassembly.
A Makita 2450 and 2470 rotary hammer can be repaired by a user with basic locksmithing skills and knowledge of electrical safety requirements.
This article discusses the mechanical part of the Makita puncher, the main malfunctions and how to solve them.
Dismantling the mechanical part of the Makita 2470 rotary hammer
To get to the mechanical part of the punch, you need to remove or disassemble the cartridge.
Disassembling the quick-detachable chuck Install the hammer drill on the back of the cabinet on the surface of a table covered with a clean cloth or paper. Using tweezers or a screwdriver, remove the rubber tip 35, item 1.
Carefully loosen the annular spring, pos. 2, the clutch cover, pos. 3, the steel ring, pos. 4. You will reach a steel ball with a diameter of 7 mm, pos.20.
Now you can remove the case of the mechanical part. It is black. Using a screwdriver, unscrew the four screws at the end of the case.
Holding the black case with your right hand, press the end of the shaft from which the cartridge was disassembled with your thumb. The plastic case is easy to remove.
Next, remove the gearbox shaft.
To disconnect the mechanical part from the electrical part, you must first remove the electric brushes. In the lower part of the body, the rotor is held by electric brushes, which must be removed.
After checking that the electric brushes are disconnected from the lamellas of the rotor, use a screwdriver to pry the metal case of the perforator at the border of the green plastic case.
Now we proceed to disconnect the rotor from the mechanical part of the punchpa The rotor is held in the mechanical part due to helical gears of the gearbox. If you take the rotor housing in one hand and the mechanical part in the other and pull it in different directions, swinging, you will separate these two nodes.
You get such a knot in the old grease. Next, unscrew the two M4 × 12 bolts, pos. 43, using the hexagon, item 2666273-7 with the internal hexagon head. Pull out the shaft with the intermediate spur gear 10 pos. 80, art.226399-7.
from the inner case pos. 49, art. 153687-8. Clean parts from old grease.
You get such a mountain of clean details. Now carefully review the details, immediately discard the rubber rings, picking up new ones.
Replace defective parts with new ones.
Mechanical makita 2450 and makita 2470 rock drill
Common mechanical problems with Makita rotary hammers include:
- destruction of the quick-release cartridge;
- bearing failure;
- breakdown of the shock mechanism;
- punch barrel wear;
- wear of rubber strikers and striker;
- gear breakage.
Repair of the perforator cartridge is done to replace the anther and rubber ring, as well as the conical spring and the steel ball, which provides clamping of the working tool (drill). What does the working tool indicate? namely, the drill is poorly held in the cartridge.
The main reason is the wear of a steel ball 7.0 pos.20, art. 216022-2. Ball wear occurs from contamination of the barrel of the cartridge due to ingress of dust and dirt.
The general view and arrangement of the Makita rotary hammer cartridge is shown in the photo below.
Do-it-yourself makita 2450 rotary hammer cartridge repair is easy to do. The cartridge must be disassembled, freed from old grease, discard rubber parts, replace defective ones.
complex failures require knowledge of the mechanical design of the Makita 2450 rotary hammer.
Having determined the nature of the malfunction of the Makita rotary hammer, proceed to disassemble the mechanical part called the gearbox.
Disassemble the mechanical part according to the attached video. Release it from the old grease. Carefully inspect all parts, their integrity, level of wear. All rubber products during any disassembly require replacement.
Consider repairing a perforator barrel. We will analyze the mechanism completely. Video disassembly, lubrication and assembly of the Makita rotary hammer
Video: Makita 2450 rotary hammer bulkhead
Repair of parts of a shaft of the Makita 2450 puncher
Remember! In the lower part of the body, the rotor is held by electric brushes, which must be removed.
At the next stage, the rotor must be disconnected from the removed mechanism. The rotor is disconnected from the mechanism simply by pulling out, because it is held by the friction of two helical gears.
It turned out such a dirty knot.
Now you need to separate the shaft of the percussion mechanism.
Most often, rubber rings, striker poses wear out. 24, compressor spring pos. 18. and cylinder parts. Here’s how barrel parts wear out and collapse during improper use of the tool.
Consider the most difficult malfunction. failure of the shock mechanism. The characteristic signs of failure of the impact mechanism is the absence of impact and the unpleasant noise of a working punch in the “Impact” mode.
Video: A moment of vandalism) (21) Makita HR 2450 rotary hammer Strong impact in impact mode
Such a malfunction is typical for those perforators that during operation were pressed strongly against the work surface. Having disassembled the gearbox, we remove debris and pieces of foreign objects. We find the defective part and clean everything from the old grease.
Very often the striker pos. 24 is destroyed, art. 324396-8, which is part of the trunk. metal ring pos. 27. art. 324216-6.
Discard damaged parts, replace with new ones, cover with a thin layer of grease. Parts are ready for assembly. But more on that in the next article.
How to repair the cartridge and percussion mechanism of the makita 2470 hammer drill barrel
Due to the ingress of dust, dirt, moisture, the internal lubricant becomes hard over time and does not fulfill its purpose. The punch starts to work with extraneous noise. Before repairing the punch, be sure to read the attached instructions for disassembling, lubricating, and assembling the components of the Makita 2450, 2470 punch. The layout of the Makita 2450 and 2470 punch will help to disassemble the failed parts and find the defective parts. And also we will tell how to disassemble the Makita 2450 puncher.
Disassembly of the Makita 2470 punch starts with the removal of the mode switch knob.
Punch disassembly procedure
Place the hammer drill on a clean surface.
When disassembling the mechanical part of a Makita 2450 or Makita 2470 rotary hammer, you must always remove the mode selector knob.
At the beginning of operation, the handle is set to the “Impact” mode (extreme right position clockwise). On the handle, using a screwdriver, poke and release the latch. After removing the latch, the handle is moved to the leftmost position, in the "Drilling" mode. The handle clamped with fingers is removed from the grooves of the housing.
Video instruction for disassembling the Makita 2450 punch mode selector knob
Video: How to put a mode switch on a Makita HR 2450 rotary hammer
The procedure for installing the mode knob To install the mode switch in the case, you must: insert the switch into the “drilling” position in the seat slot until it clicks; turn the switch counterclockwise to the “strike” position; move the switch with a click counterclockwise to the “drilling” position; insert the spring and the red button; insert the cover on top until it locks in place.
The mode switch is assembled.
At the second stage, you should disassemble the quick-detachable cartridge and repair the punch cartridge with your own hands. By the way, the cartridge needs to be disassembled only on models of the Makita 2470. The cartridge device is quite simple, and any person with a little knowledge of locksmithing skills can cope with its repair.
Makita rotary hammer disassembly procedure
Repair of the perforator cartridge begins with the installation of the perforator vertically on the rear housing cover. The hrMakita hammer drill circuit will help you properly disassemble. Is a Makita 2470 rotary hammer cartridge replacement needed? The answer can be obtained only after a complete disassembly of the cartridge with your own hands. Using a screwdriver or puller, the boot is removed, the cartridge is released from the retaining ring, clutch cover, metal ring 20 pos. 4. Next, you need to carefully get the ball pos.20, remove the guide washer pos.5 and the conical spring pos.6 that supports it. The cartridge is disassembled.
Video: Dismantling the Makita 2450 Hammer Barrel
The diagram below shows the design of the perforator cartridge.
The main malfunctions of the makita 2450 punch, causing defects in the operation of the chuck, are:
- wear of a protective rubber boot pos.1;
- relaxation of the retaining ring pos. 2 or its partial wear;
- ball wear pos.20;
- loss of elasticity of a conical spring pos.6 or its tension.
Repairing a perforator cartridge is not a complicated procedure and is usually easy to carry out by anyone who can hold a screwdriver in their hands.
If replacing a rubber boot, retaining ring, conical spring is not difficult, then replacing a new ball requires attention. The new ball must have a diameter of 7 mm ± 1 μm. As lubricants, it is recommended to use a special grease developed for the Makita rotary hammer.
The grease has an index of Makita P-08361, Makita 183477-5 SDS-PLUS 30 g for the gearbox. Makarov 196804-7 grease is recommended for drill shanks.
When assembling the cartridge, install the conical spring with the narrow side facing the punch. Do not forget, do-it-yourself cartridge repair requires careful attention from the collector.
Assembly procedure for quick release chuck
Assembly is carried out on a clean surface. Parts are pre-washed, dried and greased with a thin layer of recommended grease.
The gearbox shaft is lubricated with Makita 183477-5 SDS-PLUS grease. On the shaft in a certain sequence, all incoming parts of the cartridge are collected. After installing the conical spring, pos.6, put on the guide washer pos.5 and fix it with the ball pos.20, inserting it into the groove of the gearbox shaft. It remains to put on the ring pos. 4, the casing of the coupling pos. 3, fix the parts with the locking ring pos. 2. At the last stage, insert the protective tip pos. 1 into the end face of the cartridge, the repair of the cartridge of the Makita 2450 punch is completed. It remains to check its quality by inserting a drill into the cartridge. With proper assembly, the cartridge holds the drill from spontaneous loss.
Disassemble the gearbox
To get to the mechanical part, you will need to remove the plastic case.
The procedure for dismantling the mechanical part of the Makita rock drill. First, the protective plastic case in black is removed. The case is removed after you unscrew the four screws securing the case from the end. By pushing on the shaft end you squeeze the gearbox out of the housing.
After removing the housing, it is necessary to separate the rotor from the gearbox. A reducer is a general mechanical part. The rotor is separated from the mechanical part (gear) simply. With your right hand you need to hold the gearbox, hold the rotor with your left. Swinging, pull both sides in opposite directions. The rotor is held in the gearbox due to the friction of helical gears.
The main malfunctions of the Makita rotary hammer occur in the mechanical part of the tool.
The most characteristic malfunction for the mechanical part, the failure of the shock mechanism.
Dismantling the impact mechanism The impact mechanism is assembled on the inner casing and consists of a gear shaft and an intermediate shaft. Rotational motion is transmitted through helical gears to the countershaft.
The gear shaft is a hollow barrel in which the cylinder moves freely.
A small spur gear mounted on an intermediate shaft transmits rotation to a large spur gear of the gearbox shaft in which the percussion mechanism is mounted. And the translational movements on the gearbox shaft of the shock mechanism are simultaneously transmitted due to the transfer from the rolling bearing of the intermediate shaft to the cylinder moving in the gearbox barrel.
We proceed to disassemble the intermediate shaft.
Dismantling the countershaft
On the shaft pos. 40, a helical gear pos. 42 is mounted, on which rotation is transmitted from the rotor gear, a rolling bearing 608zz pos. 41, which transmits translational motion to the joint pos. 34 of the piston pos. 32. On the other side of the shaft, a clutch pos. 39, a spur gear 10 pos. 80, a compression spring pos. 38, a snap ring S-7 pos. 37, a bearing 606zz pos. 36 are used. Special attention should be paid to the condition of the rolling bearings. The punch has imported bearings. Allowed the installation of domestic bearings.
Bearing 606zz can be replaced with 80016, bearing 609zz is changed to 80019.
We proceed to disassemble the shaft of the shock mechanic
Dismantling the shock shaft Dismantling the barrel of a Makita 2470 rotary hammer is a simple process using the Makita rotary hammer design. The shaft is a barrel pos.21, in which the shock mechanism is assembled. A gear pos.19 is attached to the barrel, which is pressed by the spring pos.18, through the washer pos.17 and fixed by the locking ring pos.16. The cylinder pos. 32 moves in the barrel, acting on the striker pos24. On the reverse side of the striker is fixed a metal ring pos. 27, transmitting the blow to the drill. And when do you need to replace the barrel of a punch?
Most often, a metal ring fails. Striker Drum cylinder
With the disassembly, we figured it out. We change the parts to serviceable and are preparing to assemble. Learn more about grease and punch assembly.
Read if there are problems with the electric part of the punch.
Makita rotary hammer quick release video
Video: disassembling the punch makita HR2450 5 minutes before m
How to repair the stator of a Makita puncher with your own hands, video
If you determine that the stator is out of order and you don’t have funds for a new one, or if you want to repair the part yourself, then this instruction is for you. The disassembly of the Makita punch is so simple that the repair of the Makita 2450, 2470 does not cause any particular difficulties. The main thing is to adhere to the tips given in this article.
Repair of the punch can be performed independently by each user who has the skills of a locksmith and knows how to handle diagnostic tools.
Beginning of work
Any repair begins with an external inspection of the defective part. And how to find a malfunction of the stator of a Makita 2450 rotary hammer? The stator malfunction is most often indicated by the presence of traces of burnt insulation and the appearance of a burning smell. This is the first sign of a short circuit in the stator windings.
Collapsible Stator Option
But the cliff can be determined only by ringing the winding circuits.
Burnt Stator Coils
Algorithm for disassembling and manufacturing the stator of a Makita 2450.2470 hammer drill
Here is the sequence for making the stator of a Makita 2450 hammer drill:
- Removing from the stator housing assembly.
- Removing the old winding, determining the direction of the winding, the diameter of the wire.
- Winding new coils according to the template data collected.
- Insulation preparation for new coils.
- Insulation of new coils.
- Installing finished coils in the grooves of the core or winding coils in the core itself.
- Soldering leads to the ends of the coils.
- Reservation of windings of new coils.
- Impregnation of wound coils.
- Stator assembly
First things first
To disassemble the stator, use a wooden mallet or block. Tap the end of the stator housing to remove the stator from the housing. By the way, to get the stator, it is necessary to disconnect the stator housing from the housing of the mechanical part.
Do not forget to disconnect the stator lead wires from the terminals facing the outside of the collector. One end is attached to the brush holder, and the other end to the wire that supplies 220V power.
It’s time to split it into two halves.
Collapsible Stator Option
Two halves of a folding stator with wound coils
Both halves of the stator are glued together with a thin layer of glue. To separate one from the other, you need to hit the stator core with a mallet. If you did not get a collapsible stator, then the dismantling of the wire is carried out by cutting from one end of all turns with wire cutters. Cutting, disassembling, take out the wire and measure the diameter of the wire and the number of turns. Use only a micrometer to measure the diameter of the wire. Previously, the wire must be burned in the flame of a match, wipe soot and, having cooled, measure.
Most often, the coils are impregnated with an insulating varnish that does not allow to separate the wires.
Use an industrial hair dryer to heat the coils until they break into separate wiring. Soaked wires can also be heated on a gas furnace above the burner.
When disassembling the stator, it is necessary to take measurements. We need to measure the diameter of the wire, the number of turns in one coil, the percentage of filling of the groove of the stator, the material from which the wires are made. It is recommended to wrap only with copper wires.
Coils wound on a template before installation in the stator
Wires are classified by cross section. Having measured the diameter of the wire, recalculate its cross section according to the formula S = ηr², where r = ½d.
And now, in understandable language: the cross section is 3.14 times the half of the diameter squared.
Insulation and connection of leads
Why all this garden. If it turns out that you have a wire of a different diameter, then you can not do without calculations. If there is a thin wire, then winding can be carried out in 2. 3 wires, the main thing is that their total cross section is no less than the initial one.
If there is a wire of a slightly larger diameter, then you can wind it up, provided that the groove filling with the old drive was incomplete.
Option of winding a non-separable stator
For winding the stator coils, it is necessary to prepare a wire of a passing diameter, an electric cardboard or pressboard, adhesive tape, shrink cambric of the desired diameter.
If you have a non-separable stator, then in its grooves you need to make the sleeves from the pressboard, cutting the blanks along the width of the stator.
Blanks for insulating sleeves
The blanks are cut from the pressboard with a width equal to the width of the stator and a length equal to the length of the internal groove. By the way, 2 mm on each side must be added to the stator width. After cutting off the workpieces, seal their edges with wide tape. Adhesive tape 50 mm wide is suitable for the stator of a Makita puncher.
Stick the blank on one side of the adhesive tape, cut it. On the second strip of adhesive tape, glue the blanks with the same side, but the other edge. Your task is to close the edges of the workpieces from gusts during winding.
Making strips fixtures
To facilitate the manual winding process, make simple devices that are strips of soft metal up to 0.8 mm thick. It can be galvanized steel, copper, aluminum. The strips are z-shaped plates with a width of 10 mm and a length of 70 mm.
On a smaller hook, fit the heat shrink tube and heat over the flame, squeeze the tip of the plate.
Fix the obtained plates with adhesive tape on the stator housing.
The wire is prepared, the fixture plates are fixed, data on the number of turns at hand. Forward!
We put the stator on the knee, start the end of the wire, put the heat-shrink cambric red on it (it marks the beginning of the winding), fix the cambric on the outside of the stator and begin to wind. By the way, the color of cambric can be any, you just need to choose a different color for the beginning and end of the winding.
The winding process consists of feeding the wire into the groove with your thumb, inserting the wire by the hook of the fixture plate, pulling out the wire and inserting the plate by the hook on the other hand. The most important thing is to monitor the number of turns wound. The weight of the winding process is repeated for the second coil.
This is all clearly visible on the proposed video.
Video: Power tool repair. Rewind stator (field coils) part 1.
All! The stator is wound. It is necessary to carefully tie the windings, make a reservation.
Stator winding reservation process
The reservation refers to the binding of the stator coils, which protects them from destruction during operation. At high speeds, all parts are affected by various vibrations, which leads to the destruction of the integrity of the windings, their friction against each other and violation of isolation.
Booking or linking stator windings
It’s time to do the impregnation.
Stator winding impregnation process
The main task of impregnating the stator coils is to obtain a monolithic structure that does not collapse with time from vibration. Before the impregnation begins, wooden struts are inserted into the stator, pressing the coils. Work should be done carefully and accurately.
In ideal conditions, a transformer is needed for impregnation. Coil impregnation is recommended to be energized so that the wires vibrate and heat up. This allows the impregnation to flow into all the cracks. The voltage across the winding is small until vibration occurs. It can be easily detected by leaning the screwdriver against the inner surface of the rotor.
Connection of stator windings to LATR
Ideally, use a special varnish and apply it in several layers. You can use ordinary paint for internal painting in the premises of the PF-115 brand. After pouring 50 g of paint into a separate dish, dilute it with a solvent until the consistency of water.
How to soak
Using a syringe, draw paint and inject in small portions onto the stator coil until it fully penetrates into the middle of the coil. The stator should be warm and connected to an AC source. It is better to use a transformer as source, the primary winding of which is fed through LATR.
Voltage for impregnation through LATR
Remember to control the stator temperature. To the touch, the hand hardly withstands the temperature of the case. At a higher temperature, reduce the supply voltage to the transformer using LATR.
The consistency of the paint depends on the diameter of the wires. The thicker the wire, the thicker the paint. Impregnate until paint appears below. Turning the stator over, continue to impregnate. Leave the stator under direction until completely dry.
The stator is impregnated and, after cleaning from traces of paint on the inner surface of the stator, is ready for assembly.
Stator impregnation and rewind:
Video: Stator impregnation. Winding in two wires with parallel connection.
Now you are ready to assemble the Makita rock drill. If you think this is difficult, then rewind is best left to professionals.