Meat grinder DIY repair

In detail: do-it-yourself meat grinder repair from a real master for the site my.housecope.com.

While scrolling the meat, a medium-sized bone accidentally fell into the meat grinder, after which it began to hum, but stopped rotating.

It is easy and simple to disassemble the meat grinder, for this in the lower part of the case you need to unscrew four screws with an ordinary Phillips screwdriver, after which it is very easy to remove the casing. After that, we remove the large gear by picking up and removing the split fixing washer in front of these.

When I examined the gear, I noticed that many of the plastic teeth were worn off. I had to change it, because I didn't want to pay 500 rubles for a new gear, I printed it on a 3D printer. Collected in reverse order, everything works

After they put crackers in the meat grinder, it began to crack and after a while stopped twisting, I had to carefully disassemble it in order to identify and eliminate the malfunction.

Disassembly is quite simple, first we remove the front gray panel of the latch from the bottom, then we unscrew the five screws and separate the halves. Now you can clearly see the motor and the gearbox housing

We unscrew the four self-tapping screws on the gearbox housing and open it. We see broken teeth at the largest gear. It was not possible to find them on sale.Therefore, they were borrowed from the VITEK meat grinder, although it was necessary to sharpen the hexagon axis a little and the auger seat.

The meat grinder seems to be working, but at the same time it makes extraneous noise and sometimes pops, there were no such sounds before.

In order to repair the meat grinder, you will need to determine the source of the problem and disassemble the electric meat grinder.First of all, we will unscrew the screws, which are marked with red arrows in the figures below.

Video (click to play).

Now we disconnect our disassembly object into two parts and see that it consists of two main units: a gearbox, in which plastic gears are installed, and an electric motor, thanks to which rotational movements are carried out.

Now you can disassemble the gearbox to check the gears and the engine.

After that, remove the gear cover. Plastic gears are installed each on its own rod. Remember the location of the gears, or better yet, take pictures of them if they differ from our image.

After dismantling the gears from the rods and inspecting them, I found fractures of plastic teeth on the smallest of them. The breakdown is unpleasant, because to repair the meat grinder, you will need to replace the gear, but it will not be so easy to find it, because you will either need to find exactly the same killed device, or order its manufacture from a familiar machine operator. You can also try to order different sets with similar elements from China, but it is not a fact that you will get there.

In many models, the coupling is a calculated weak link, which must break first when the mechanism is jammed, so that the gears of the reducer and the electric motor remain intact. This sleeve breaks off only when it is sufficiently hard to jam. Such protection is relevant for meat grinders of almost all firms in which the gears of the gearbox are made of plastic. If overloaded in some models, the gear teeth can be ripped off. This will lead to more expensive repairs. And in this case, you can do it yourself by changing the special bushing, which is usually in stock.

The electric assistant today is very popular and in high demand among Russian buyers. Despite high-quality manufacturing and high reliability in operation, electrical appliances tend to break down over time.Many breakdowns can be repaired at home, so we will tell you in detail about the repair of an electric meat grinder, which you can easily do with your own hands.

It doesn't matter what kind of meat grinder you have - Kenwood, Zelmer or Moulinex, each of them has its own nuances, but the faults are pretty typical for all. Electric meat grinder repair specialists have compiled the following register of the main problems encountered in these products:

violation of various contacts of the electrical circuit;
deformation of the engine rotor;
breakage of the teeth of the gears of the reducer - arises from the increased load;
malfunctions of the electric motor, extreme wear of the brushes;
wear of the cutting tool due to the processing of too stringy meat, the ingress of small bones due to the user's oversight;
breakage of keys, safety devices;
damage to insulation, power cord;
replacing the motor or rewinding its windings.

Many failures of reliable technology are due to violations of operating conditions and only a few - a factory defect or a human factor during assembly.

If any malfunction occurs, it is necessary to immediately carry out diagnostics in order to find out the cause and localize the breakdown. Inspection of the mechanical part of the product is carried out visually, and the electrical circuits are checked with special devices. If a visual inspection of all parts of the mechanical part did not give a positive result, then you need to dismantle the product and inspect the gearbox, electric motor. May have happened clogged lubricant rubbing parts, the bearings do not work correctly, they need to be replaced.

Timely diagnostics allows you to identify and eliminate malfunctions at an early stage of their development, which significantly extends the life of the entire product.

Let's consider in detail the malfunctions of the meat grinder and methods of their correction.

The engine does not reach the set speed - the reason may be broken switch or the engine itself. Replace worn mechanisms or an electric motor.
Interruptions observed in the drive - extreme wear of graphite brushes, you need to install new ones.

Extraneous sounds, burning smell during product operation - defective engine... To restore it, you need diagnostics, repair or complete replacement. However, the cost of replacing the engine is quite high - it would be more cost effective to purchase a new grinder and solve the problem.

The reason for the appearance of sounds unusual for the normal operation of the meat grinder may be bearingsthat wear out during operation. To confirm the diagnosis, it is necessary to disassemble the main body of the product, get to the place of their installation and check the rotation, if necessary, replace it.

Reducing the speed of the electric motor - overload, the food is fed too fast, the meat grinder does not have time to grind them. The Kenwood mg model is particularly susceptible to this malfunction. Reduce the feed dosage and everything is normalized.

No shaft rotation - the transmission mechanism of the reducer is seized... Perhaps one of the gears or its teeth is broken and needs to be replaced.

The product auger has stopped. If at the same time the engine is operating in the same mode, then turn off the meat grinder and dismantle its mechanical part in order to find out the reason.

In the latter case, there are several reasons for the occurrence of such an unusual failure: incorrect assembly of the gearbox, cranking of the motor shaft, breakage of the drive gear teeth, and very rarely licking of the connection by the auger shaft (erasure of the hexagon).

On a note! The non-conformity of the metal of the part leads to its breakage during the ultimate load.

If the hexagonal receiver, where the auger shaft is inserted, is made by mistake of a softer metal, then during operation it quickly expands, or its edges wear off, the tight contact will be broken... The same can happen with the auger tip. It is difficult to repair a meat grinder with such problems with your own hands; the help of professional repairmen of similar equipment is required.

In order for the electric meat grinder to delight you with flawless work for a long time, you must follow simple recommendations for proper operation:

before starting work, always carefully check if the assembly is correct and reliable fixation of all parts;
pay special attention to the contact between the cutting tool and the grate - they must fit snugly, the fixing nut must be tightened with effort;
cut the product into piecesnot exceeding the diameter of the loading cylinder, in order to avoid them getting stuck;

disassemble, clean and rinse all parts and the internal volume of the meat grinder after each use;

keep all parts of the mechanical part of the product only disassembled.

Special attention! Before processing meat and fish, it is necessary to free them from bones, remove large veins, make sure that small bones that can damage the knives do not get inside the product.

Do not turn on the meat grinder without loading, do not try to push through the stuck pieces of food with your hands - there is a special pusher for this, never overload it. If you thoroughly fulfill all the requirements, then the product will work flawlessly for the entire period assigned to it by the manufacturer, and she will not need repairs with her own hands.

It's easy to guess: there is an electric motor inside the meat grinder, supplemented by a rotation speed control circuit. If we put aside the cases when it is necessary to replace the protective sleeve, coupling, repairing meat grinders with our own hands concerns the knowledge of the theory, the practice of the operation of AC motors. In electric motors, collector designs are more often used by consumer electronics; in industry, asynchronous ones dominate. Newbies will ask where the authors got their information from. We answer: according to the Ariston service department, since the 90s of the last century, collector motors have been replacing asynchronous motors in the household segment. Today, the percentage of the former reaches 85 of the total. On this bright note, let's start looking at AC electrical machines and control methods.One often hears the statement: brushed motors work equally well on AC and DC. Let's say more: the alternating current loses part of its power, passing through the stator and rotor chokes, the inductance tries to delay the frequency. 50 Hz is a bit too much for a simple lacquered wire spool. Often, the stator windings are driven out individually, as they are. You can power one. Power suffers, losses are reduced, reaching a minimum size.How easy it is to regulate an induction motor. Found two methods used by meat grinders:

Changing the amplitude of the supply voltage.

Commutation of windings.

It is clear that the first method requires the inclusion of additional elements in the circuit. I would like to notice about this! I happened to read on the forum about the domestic speed controller of an asynchronous motor, as if there were only resistors. The author hinted at the presence of a resistive voltage divider. But! When the active element operates in a linear mode - most regulators are built by thyristors - the resistance is far from infinity or short circuit. They put radiators, protecting the semiconductor keys, we will touch on the topic below. We would like to bring to the attention of the reader: there will always be losses.A little blood is not enough. The grinder device contains a motor with two windings, a starting capacitor, the rotor is represented by a drum, we see a 100% asynchronous motor with a squirrel cage rotor. Let's meet a circuit with switching windings. As follows. One coil is wound around the periphery, connected through a capacitor, providing the desired phase shift.The second is wound at an angle of 45 degrees around the circumference, there is no phase shift. One is divided by two unequal windings. Each can be switched on separately, in parallel (together). Gives three speeds.Let's add asynchronous motors to the theme. The manual for the repair of meat grinders will forget to mention a trifle: a thermal fuse designed for 135 degrees is often placed inside the windings. Foreign elements are often decorated with the letter F, the number has little to do with Fahrenheit. Unlike Elenberg transformers, where the braid honestly writes: there is a thermal fuse inside, asynchronous motors are often devoid of mention. Call the windings: one suffers a break, patiently inspect for different elements hidden between the wire. It can be difficult to do, believe me. The first glance shows only copper, the second - copper, the third - an element of protection is noticed.The thermal fuse is found, it should be evaporated, ringing. With a positive breakage test, get a new one, solder instead of the old one. Can you guess why you can't short-circuit? Right! The next time it is not the thermal fuse that burns out - the asynchronous motor, the hassle will increase. Similar radioelements are found in many products, there are no special requirements. Surely there is a suitable specimen at the flea market. Be careful not to tinker yourself. As is the case with the regulation of the speed of induction motors. The method of dividing the voltage by a thyristor is suitable; in practice, current cut-off is used.

The supply voltage is supplied bypassing the brushes in series on the rotor and stator. The direction of movement of the shaft is determined by the direction of the windings.

The current flows through a thyristor switch controlled by the sum of the voltages.

The source of the switching signal shaping determines the complexity of the circuit. Brush motors spark. When switching sections, a back-EMF occurs. Directed opposite to power supply. Apply feedback. Through a capacitor, the back-EMF diode is added to the thyristor control electrode. The more the amplitude, the less the gateway is open. The motor starts, or the load increases - the speed decreases. The amplitude of the self-EMF becomes less, the key current increases, and the engine returns to the mode. Needless to say, how important it is to keep the speed constant, the circuits solve this problem. It is clear that part of the power is lost on the key, the inevitable payment for stability. The speed can be adjusted separately via a variable resistor. Who is interested - you will find good options here

Read also: DIY rusty body repair

The meat grinder is open, we begin to inspect the engine. It is necessary to measure the resistive input resistance. If a capacitor is visible in the circuit, we define it as an open circuit, it is misinterpreted, considering it a breakdown. To repair the grinder yourself, check the proposed engine type. Traditionally collector, it is easy to recognize, thanks to the characteristic drum, broken by segments, two graphite brushes are diametrically adjacent. Asynchronous motors are sold with squirrel-cage, phase-rotor options. In the first case, the rotating part is devoid of electrical contact with the stator, the power source, in the second, there is a pair of rings supplying current to the rotor windings.The difference between an induction motor with a phase rotor - the shaft is devoid of a segmented drum, there is no pair of brushes. Repair of electric grinders is carried out according to the type of engines. The asynchronous entry is ringing anyway. The collector engine is not enough.We will ring the section, rotate the shaft, measuring the resistance of each step. The values must be equal. The process stops - the turnover is completed. In collector motors, the stator is often made on a single coil. It is connected to the rotor by a magnetic circuit, represented by a core with wire turns. Do-it-yourself meat grinder repair will be a freebie.Even if the wire is burnt in the center, always buy a roll of a new one with lacquered insulation in the store, wind the required volume with your own hands.They use a device formed by two pairs of racks mounted vis-a-vis on a long board. Each has a rotating axle. One holds a new spool, the other holds a coil of wire. Here you wind up the old choke to localize the break, how many turns to wind, what is the length of the wire. Most people use a handle, like an old barrel organ, it is allowed to use a screwdriver drive, a drill. Determine the speed so that it is convenient to lay the turns tightly. With the shuttle, the other hand guides the wire from side to side, from edge to edge of the spool. In conclusion, we will ring the coil and measure the electrical resistance.Repair of induction motors is determined by the design. The stator is repairable. The configuration of the rotor windings is complex (if any). However, if there is a lot of strength, time, desire to practice, it is impossible to stop the master. Let the day be spent, the engine again works as part of the meat grinder.

The two stator windings of the electric motor are offset from each other by ninety degrees. The current in winding B differs in phase from the current in winding A, due to this difference, the initial start of the rotor is ensured.

The difference in the currents of the two stator windings is created by a capacitor, namely, the current value for winding B will be greater than that for winding A. That is, the capacitor in the electrical circuit here serves to ensure the initial acceleration of the rotor.

The electric motor of the meat grinder is asynchronous, the rotor speed of which lags behind the rotation speed of the stator magnetic field.

Consider some of the causes of a malfunctioning electric meat grinder. For example, your diagnostics established a capacitor malfunction. How to choose the right capacitor?

The tolerance in the deviations of the capacitance of the capacitor is not important, since the deviations in the capacitors are insignificant. Important characteristics are the capacitance of the capacitor itself and the nominal voltage value of the capacitor.

The next reason for the malfunction is a burned out electric motor. With such a malfunction, it is easier to replace the electric motor itself, if the cost itself is more acceptable for purchase.

These parts are available from the radio store. If the capacitor you need is not on sale, the capacity of the capacitor you need can be selected from two separate capacitors, let's say two capacitors. In this example, to increase the total capacitance, two capacitors are connected in parallel.

Minor causes of malfunctions include:

break in the mains cable wire at the base of the plug;
break in the wire of the network cable along its length

A general diagnosis of all connections can be carried out - with a probe. Diagnostics of the electric motor is carried out with the Ohmmeter device or the Multimeter device, previously set to measure the resistance of the stator windings of the electric motor.

More and more often, in the trade market and even in large mega-tech centers, buyers ask sellers about the guaranteed level of reliability and the quality of the purchased goods. Some people really want to sell the product. Others want to buy it, but a third party produces what someone will buy anyway.

Believe it or not, a lot of brand-name products are often ‘children's toys’.

Another indignation of the hostess was caused by the recently purchased electric meat grinder. In the assembled state, when the electric motor is turned on, the auger rotates. When feeding the product for chopping into the auger chamber electric meat grinder auger stops even though the motor runs non-stop.

There are several reasons that can cause such a malfunction.

Inaccurate assembly of the transmission mechanism.

Sometimes the ‘curious’ owners of electric combines or ordinary electric meat grinders are drawn to carry out maintenance, which often ends in ‘technical murder’ or ‘mutilation’ of the kitchen unit.

During such services, hammers and other tools for other purposes are used. Lubrication of rubbing parts with sunflower oil or complete removal of factory grease. Replacement of parts made of inappropriate material, repairs using inappropriate glue, open fire, impacts. With this technique, skews appear in the axes of rotation, chips, and an uneven gap in the teeth of the gears.

Breakdown of the motor shaft from the drive gear of the reducer.

The drive gear of the reducer is mounted directly on the rotor shaft of the electric motor. On different models of an electric meat grinder or food processor, the gear is fixed on the motor shaft through a key, pin, through lock, spline connection or pressing.

Due to jamming in the gearbox, with excessive load on the auger, overheating of the electric motor with heat transfer to the shaft, the fixation between the electric motor shaft and the drive gear is weakened.It breaks the splines and the key, and when the locking connection is made with a through lock, the gear breaks, the pressing weakens immediately. In such cases, the rotor shaft of the electric motor rotates freely in the drive gear housing.

But, when the gearbox is still reliable, then stopping the electric motor can lead to overheating of the electric motor windings and its failure.

The auger in the chamber without load can rotate intermittently or evenly, but slower than usual and with a characteristic sound. Electric meat grinder gearbox also has its own sound, which is also manifested in good condition.

Broken teeth on the transmission gears of the reducer.

A similar case is rare and more on old units or on an assembly with low-quality material. When the teeth of the gears are worn or when the gap between the teeth of the intermediate gears is uneven, one of the gears of the reducer jumps tooth to tooth with jamming or breaks loose teeth, the fragments of which fall into the gaps between the remaining teeth of the gears.

When the teeth on the gears break off or the gears of the reducer wedge 'tooth to tooth', the rotor shaft of the electric motor can turn in the drive gear housing with a press-fit connection or tear off the pin, key or retainer.

Rotation of the shaft in the drive housing or in the driven plastic gear wheel of the gearbox.

Modern electric meat grinders are usually equipped with synchronous electric motors with sufficient shaft power.

When the gearbox jams when the electric motor is on, the connection between the motor shaft and the drive gear is often weakened. Can tear off a key, pin, slot. The fixation of the motor shaft with the drive gear will weaken and the shaft will turn in the gear itself.

In the case when the gearbox is made of durable material and assembled without violations of the assembly technology, there is a rotation of the driven gear on its shaft, the elongated part of which serves to transfer rotation to the meat grinder auger through the 'shaft to shaft' connection. But this very rarely happens when the rotating auger is completely jammed and its shaft and the driven gear shaft are tired.

And the most unpredictable and not uncommon reason is ‘licking’ of the driven gear shaft of the reducer by the auger shaft.

The hardness of the steel used for the auger shafts and the driven gear of the reduction gear is insufficient. The steel is soft and very easily amenable to any cold work. There is even a trace of a simple kitchen knife.

With the next assembly of the auger chamber for chopping some product, the tightness of the 'shaft to shaft' connection between the auger shaft and the driven shaft of the gearbox weakens over time. The joint gap increases and there comes a moment when, with an increase in the load on the meat grinder screw, the shafts rotate relative to each other. The edges and edges of the shafts 'lick' and the stronger the softer the steel and the greater the load.

It happens that the manufacturer did not provide for the full compatibility of parts and completes his product with parts only in some parameters, that is, it corresponds to the diameter - does not correspond to the length, corresponds to the length and diameter - does not correspond to the fastening. And the main discrepancy is the discrepancy of the material for the parts used to the expected degrees of stress on them.