Why is the speed preset on your drill?

Hand drill: how useful is this tool

Power. Definitely affects the performance of the tool and greatly expands your possibilities. For a cottage industry, this is important. For example, you can use drill bits of bigger diameter and length, and drill holes of 25 centimeters in a bar without any problem. 500 watt is not enough for the country house workshop but 800 to 1100 is good enough!

Virtually any modern power drill has speed control by the force of the trigger. It is much better when there is a regulator on this trigger, fixing the speed you choose. And better yet, the drill has not only one but two speed settings. I do not separate these concepts, as is often done for advertising purposes. It really is quite simple. Just like a car when shifting gears with a gearbox. And the presence of a downshift significantly increases off-road capability!

The most important advantage of such a gentlemanly set of speeds is that when you buy it, you you get a great mains electric screwdriver

With reliable tuning and adjustment. You can actually drive very heavy screws. Without a cascade of these downshifts, you’ll just cut the screw heads off if you try to activate this option. You can use such a drill in a “drilling machine” frame. The clear speed locking of the drill will allow you to drill evenlywhen the trigger is locked (trigger) of the drill. At low speeds it is easy to drill in metal and at high speed you can drill quickly in soft woodsharp with drill bits.

Generally, one should handle with care the high speeds of drills, because it is possible to inadvertently overheat and spoil a good drill, or “fry” the wood.

The traditional chuck is a toothed chuck. It has a drill bit clamped with a wrench. This “obsolete the ” version is still found in nearly all extra powerful drills. Such chuck allows to fix the drill bit more firmly and structurally it is much more reliable.

The quick-action chuck is not much worse at holding the drill bit, which is more than enough for countryside applications. Also. It’s incomparably more convenient

Even more preferable is the versionQuick-action chuck that can be locked and unlocked with one hand.

In any drill you can change the chuck. To do this you open the chuck as if you were going to insert the drill bit with the largest possible diameter. Then you will see a screw (with back thread) in the back of the chuck!). Drop some WD lube on it and try to unscrew it after a while. After removing the set screw, you can unscrew the chuck itself. It should be done carefully, so as not to damage the head of the setscrew. The chuck can be locked from rotation with the key (in the case of a toothed chuck), or with any other soft locking (through a thick rubber gasket, such as a pliers or vice). Well, if it comes by hand, consider yourself lucky!

The most important task of the handle is comfort and reliability. No less important is how quickly you can change the locking position of the drill, even to the point of full disengagement. There are a lot of variations, and each company seeks to bring its own know-how to this field. Reliability of the mount can be estimated visually, but the other conveniences are very subjective. I liked very much the design, where clamping on the drillstring is made by turning the handle like changing gears on a bicycle. The movement is natural and there is no need to prepare for it.

The drill is considered a comparatively safe tool. But! If the drill jams, the power drill makes a jerk: it is not the drill that rotates inside the drill, but the drill around the drill. If you are not ready for it, this kind of stunt can easily twist your hand. This is, perhaps, the main specific danger of a drill. Fortunately, this rarely happens with a drill bit. But if you spin solid wood screws in electric screwdriver mode and don’t knock down the speed in time when the screw is “ready”, the drill will try to “do somersaults” all the time.

The hammerhead is a tool of a bygone epoch

Like almost any hand tool, which man has invented an electric equivalent, the hammer drill is outdated. But do not rush to throw it away, if you dug out such a relic in your workshop, as the tool has not changed its relevance. The most important advantage of this drill is the muscle “pull” work. It needs no electricity, no battery, just steady hands.

It looks like the simplest device of the two parts. the frame and the drill chuck. The frame is bent in four places, forming an incomplete square or rectangle. the bent part is the handle, thanks to which it is possible to rotate the entire structure around its axis quite easily when the master exerts force. On the top of the frame for convenience the handle is attached, which remains immobile when the frame is rotated in the hand. Quite often the earth drill in the understanding of users is also called a chisel, but, in fact, it is only one tool, namely, a drill.

There is even a special GOST. 25602-83, dedicated to spanners with interchangeable heads. While the service life of the frame of the device is almost unlimited, the chuck under intensive use comes into disrepair rather quickly. The chuck is a double-sided attachment, in which at one edge the drill is fixed, on the other side the frame is fixed.

By the way, this tool can be used not only as a drill, but also as a powerful screwdriver. All that is needed is to make a stinger with the appropriate configuration for the head of this or that screw. In this case it is worthwhile to sacrifice an old screwdriver and turn two “old boys” into a very functional tool.

Picture of a spudger, v063.photo. modern hand drill. rotary hammer, santoolgroup.fcPictures of drill spindles, petr.Picture of two-handed hand drill, forumavia.uFoto of hand drill, 900igr.net

The simplest variant

The easiest way to change the speed is to use a direct current motor. They can be varied by simply changing the supply voltage. And it does not matter where: at the armature or at the excitation, but this applies only to low-power machines with minimum load. Speed control is mainly effected by the armature circuit. over rheostat control is possible here if the motor power is small or there is a quite powerful rheostat.

This is the most uneconomical option. The mechanical characteristics of an independently excited motor are the most unfavorable because of the large losses resulting in a drop in mechanical power, efficiency.

Another possibility is to insert a rheostat into the field winding. Looking at the characteristics of a motor with independent excitation, we see that the speed control is only possible in the direction of increasing speed. This is due to the saturation of the winding.

So, the rheostat control of speed of rotation of separate excitation apparatus is justified in systems with minimum load. It is best if the operation with such switching will be intermittent.

Read more:  Rotary hammer drill lubricant how to use

Frequency regulation

Special devices, frequency converters (other names are inverter, frequency converter, driver), are connected to the electric machine. By rectifying the supply voltage, the frequency converter internally generates the required frequency and voltage values and feeds them to the electric motor.

The inverter calculates the required parameters to control the motor according to the internal algorithms programmed by the device manufacturer.

Advantages of frequency control

  • Smooth regulation of motor speed is achieved.
  • Changing the speed and direction of the motor.
  • Automatic maintenance of required parameters.
  • Economical control system.

The only drawback to be reconciled with is the need to buy a frequency converter. The for such devices are not exorbitant, and within 150 cu, you can get the converter for 2 kW motor.

speed, your, drill

How the peorator works

During construction or finishing works, you can’t do without special tools. One of the most popular and versatile is a peorator. In this article a master plumber will explain how it is tripled and how it works.

The word pehorator literally means “drilling hammer”. To increase productivity in mining operations, the jackhammer was developed in the early 19th century. The principle of the device was to use a flywheel. It actuated a rod with special pawls attached to it. The rod under the influence of the spring strikes and is returned by the piston.

The device has been continually improved. In 1932 in Germany, Bosch Corporation invented the first electrically powered torch. Impact and rotation torque were combined in this device. The principle of action developed by the company is still used in today’s models of electric peorators.

The peorator is a device designed for drilling holes and breaking up hard rock. Various drill diameters and chisels are used as consumables. The tool is divided according to the class of application:

In addition, it is distinguished by the mechanism of operation, which is electromagnetic and pneumatic. The last type was available in one, two and three modes. So it is possible to drill, punch or perform both operations at the same time.

The tool resembles a pistol and can work using an electric, fuel or pneumatic drive. The latter are used in dangerous working conditions, during which there is a possibility of an explosion.

The hammer mechanism is the basis of the rotary drill principle that sets it apart from other similar tools. The electromagnetic type uses two electromagnetic coils that provide reciprocating motion of the core. It transmits the inertia to the drill shank. The pneumatic type is based on the movement of the piston in a cylinder, which also reciprocates.

An electric torch uses the rotation of the motor to convert the hammering/rotating motion of the auger. Clutch used in the design provides protection at increased loads. Drill bit bearing and piston provide the impact force, while the drill chuck provides the clamping force.

  • In chisel mode, the chuck performs only reciprocating motion. This mode is necessary for chiseling and cutting holes with a flat chisel. Drilling, especially deep holes, in such mode is not recommended, it with high probability will lead to jamming of the drill;
  • Impact drilling mode is used for drilling holes in concrete, porcelain, cast stone, and natural stone. For household rotary tools, this is the most popular mode;
  • Drilling mode (without impact) may be required for making holes in bricks, cinder block, or aerated concrete, since drilling with impact may break the hole in such materials. This mode on the tool with a removable chuck allows the chuck to be replaced with a cam-type chuck and the torch can be used as a drill.

Each manufacturer strives to improve the design by applying design features. Mainly minor adjustments related to the use of different materials and their location. In general, the basic elements remain the same.

Additional design features include a dust extraction system and a vibration suppression unit. For the multi-mode type of the tool, a button is installed to switch the work.

Collector type drive is used in operation. Depending on the model power, horizontal or vertical mounting of the motor is possible. In the first case, we are mainly talking about the models of the light class of domestic use. This technical solution is characterized by simplicity and convenience (especially when it is necessary to work in places with difficult access). Among the disadvantages of this option is insufficient cooling of the motor and the high load on the power plant.

The advantage of a vertically mounted electric motor:

  • Reduced vibration level;
  • intensive cooling (which is especially important for high power equipment);
  • In such tools, the piston always moves with a greater amplitude.

This type of tool is designed for continuous duty under severe conditions.

The motor drives all the other parts of the mechanism. It consists of a stator and a rotor, with the rotor being the moving part and the stator not. The rotor includes an armature and manifold. Anchor is such a block containing plates of steel. They are wound with windings of copper wire. The armature, in turn, looks like a cylinder. Its design is in the form of dielectric with conductive plates installed, and the armature windings are connected to these plates.

Using the drill as a machine tool

A typical diagram of a drill speed regulator.

The hand drill can be used out of the box. It is used to build a variety of machines: drill, grinder, circular and others. The speed control function is very important in these machines. Most domestic drills have a button that controls the speed. The harder it is pressed, the higher the RPM. But they are fixed only at the maximum values. This can be a big disadvantage in most cases.

You can get out of this situation by making your own version of the speed regulator. The dimmer, which is usually used to regulate lighting, can be used as a regulator. The speed regulator is simple enough and is shown in Fig. 1. To make it, you need to connect wires of different lengths to the socket. Connect the long wire with the other end to the plug. The rest is assembled according to the scheme. It is recommended to use an additional circuit breaker, which will shut off the device in case of emergency.

Home-made RPM regulator is ready. You can do a test run. If it worked well, you could put it in a suitably sized box and fasten it to the bed of the future machine in a convenient place.

Basic functions of a turnover regulator

There are a lot of things that can be achieved with converters like this one:

  • possibility of stepped acceleration and reduction of the electric motor rotation, which leads to decrease of loads and lower consumption of electric energy;
  • it is possible to implement a smooth start, and the instantaneous maximum acceleration of the motor gets superhigh loads, overheating the winding and other actuators;
  • as a means of additional protection of electronic mechanisms;
  • Reduction of maintenance costs of power units and pumps, because the risk of breakdown of the drive and separate mechanisms is reduced.

Welding machines, voltage regulators, PCs, televisions, etc. are not without similar built-in devices.д.

Power tool power regulator.

Hello! Of all the tools I have, the most used is an angle grinder (angle grinder). In addition to cutting of different materials, very often used for cleaning, sanding surfaces. When working with wooden materials, the flap wheel often burns the wood. Too much rpm. Velcro circles on tiles also tend to fly off from the centrifugal force. I saw the solution in adding a speed controller to the angle grinder. The search criterion was the ability to fit in the tool body with the least amount of effort.

Read more:  Speed ​​Control Angle Grinder

Faithfully another angle grinder serves me for the sixth year. Manufacturer DILD, 125 wheel. precise designation has worn off due to time, and I do not remember myself. Did not want to make a remote control. There is a little space in the handle. After looking at the dimensions of the knob on the seller’s page and deciding that I’ll put it in after all, I ordered. Took me about a month to get the package, but I can’t track it. Product page specs.

Model: 6 speed Maximum voltage: 250 (V) Rated heating current: 6 (A) Operating temperature: 0-50 © Material: plastic.

Not 6 speeds, of course, stepless adjustment potentiometer. Figures for clarity.

Length. 30mm; Width. 17mm; Height. 30mm. At one end of the el. characteristics. On the opposite side of the circuit.

An approximate wiring diagram of the unit. The controller under review differs only in the trim potentiometer and the switch (beyond the 6 position of the el. the adjustment is switched off and the mains voltage is fed directly to the tool).

The inside of the housing looks like this. Triac is used VTB08.

VRRM, V 600 IT(RMS) (max.), A 8 VDRM (max.), V 600 IFSM (max.), A 84 IFT, mA 35 dV/dt, V/µs 400 dI/dt, A/ms 4.5 TA,°C from.40 to 125 Can be used without heat sink up to 1000W. Reverse side only solder.(I covered with flux, the complete wires are short) Disassembled angle grinder. There is only room for the instrument here.

Sawed hole in enclosure. Angle grinder handle body made of ductile plastic. The regulator fits very snugly. I did not fasten it with anything.

Location is just right. Doesn’t interfere with the tool. Approximately 5 mm did not fit all the way, is not critical absolutely. The main thing is that it is easy to use.

The voltage regulator changes smoothly. Connects to the power supply cable. On the first position the voltage is 154 V. In the sixth position 201 V.

I have a low-power angle grinder, so it stops on 1 and 2 positions when cutting metal. But it works fine from 3 onwards. What I expected from the regulator, I got. Grinding tile at work. The head does not try to escape from the platform, there is less vibration and there is not such a column of dust. Chamfered the face of a board with the flipper wheel. doesn’t burn the. Now the angle grinder fully justifies its name (angle grinder).machine). I turn on the angle grinder on the direct connection to the network, and then turn it down to the right speed. Although it can also be run at low speed. Maybe I shouldn’t, just in case. It is on the video.

Thank you all and have a nice shopping!

Repair of Drill RPM regulator. Case study

The second article of the summer contest. This time the author is known to the regular readers of the blog. This is Alexey Sidorkin, who already participated in the first contest with an article about homemade time relay.

Alexey is not only the author of the blog, but also an active commentator. His helpful Комментарии и мнения владельцев under the pseudonym “Alex S” can be found under many articles on SamElectric.ru.

I think everyone has had more than one event or case in life, which he could not find a suitable explanation, remaining a secret for a long time. It happened with my drill.

My son-in-law Dmitry bought this drill Bosch PSB 500 RE in May 1998 in order to equip his newly obtained apartment. At that time, such a prestigious tool (power 500 watts, adjustable speed, reverse rotation, the possibility of percussion mode. “Peorator”) in the economy did not have everyone. The purchase made me quietly jealous. I had a simple Soviet drill without any “contrivances”. My daughter gave me the Bosch drill later, after my son-in-law was tragically killed in a car accident in 2002.

Of course, my use of the tool was not a “every day from morning till night”, the drill was used for household needs, as in most normal families, plus the summer season at the cottage.

The drill was working properly, successfully performing all its functions and options, and suddenly, about 5 or 6 years ago, the speed regulator stopped “obeying”. in any position/settings of the wheel/control knob, the drill immediately gave full speed without any fluidity when the trigger was pulled. The first thing that came to mind why there is no low RPM. “burned out” the circuit speed control drill. But by that time in the household there were other tools, including an electric screwdriver and another drill in the village, and the work of the Bosch drill in low speed mode was not so relevant, hands to fix the problem never reached.

Just recently I had to work carefully with a drill, and its high speed turned out to be very handy, and other tools with a chuck at hand was not. There is an appliance repair shop not far from my house. There I was told that the speed controller (hereinafter referred to as RPM) for the Bosch drill is “made to order”, to wait at least 2 months,

I decided to figure it out on my own, as, after all, the adjuster of power equipment [1], although retired.

I am a technician, but I went to a repair shop? If it is urgent, but for a couple hundred (earlier it was called “for a bottle”), then there is no point in “unpacking your rifle”, it is necessary to let others live too.

speed, your, drill


I opened the drill, disconnected the control board (two electric contacts split by knife-type, two “for screws” and one screw fixing the power wire. Fig. 2).

Drill rpm controller is a separate unit. In Fig.3 Almost life size of the two halves (lid and housing) of the opened PM, material is plastic, halves are clicked together.

Fig.3 are marked: 1. contact group; 2. sliding contacts; 3. resistor strips; 4. adjusting screw handwheel; 5. trigger return-push spring.

The body of the speed regulator for the drill has a contact group 1 and sliding contacts 2 in the form of two spring plates, which are driven by the pull of the trigger and come to rest under the action of the return-pressure spring 5.

In the cover there are a capacitor (below) and the board (above) with elements of electronics and two resistor strips 3, on which, when the trigger is pulled, the contacts 2 slide for smooth change of the tool speed. The resistance strips are coated with a special grease to protect the strips, reduce friction and prevent arcing of the sliding contacts.

The adjusting screw with the handwheel 4 on the trigger limits the depth of the trigger and the distance/length of the sliding contacts 2 on the resistor strips 3, thus defining the regulation range and the maximum speed of the drill. If the adjustment screw is turned all the way out, the trigger, when fully depressed, closes the contact group for direct engagement of the drill motor, bypassing the electronic adjustment elements, and the motor runs at the maximum possible RPM (3000 rpm).

Drill speed controller circuit is almost identical to the rotary dimmer circuit. Only difference in design and dimensions.

My scope of work included check of trigger’s clearness on pressing, contact group parts interaction, adjustment screw rotation, adjustment of grease distribution on resistor strips, cleaning of accessible places from accumulated dust and dirt. No faults, malfunctions or suspicious points were found. In other words, I made a small revision, then reassembled the drill, turned it on and the RPM regulator started working as if nothing had happened!

Read more:  Mini drill with adjustable speed

Thus, the repair of the speed regulator of the Bosch drill is reduced to trivial cleaning!

There were many suggestions as to the causes of temporary damages of the drill. from shock or unnoticed dropping of the tool to defects in electronic parts. However, analysis of the situation still tends to malfunction pair “sliding contacts. resistor strips” for some unknown reason, it is enough that just got a tiny particle (particle) under one of the sliding contacts. and that’s it, there will be no adjustment. This is also indicated by the fact that the tool is immediately turned on at full speed, which is possible only when the contact group is actuated.

But, no matter what, it turns out that the tool turned out to be an electrician and repaired itself!

Question from a reader

I received an email from the reader Alexander, with such a request:

Good evening. Came across your blog where you are repairing a Bosch drill. I have a similar problem, only I have almost nothing to do with electronics. Foolishly disassembled the trigger of a Bosch gsb 1600 RE drill. Everything was working fine before, assembled it somehow, now the soft start doesn’t work. Maybe I put the parts in the wrong order or in the wrong place. I enclose a photo of the disassembled. I hope to help, it is a good drill.

Bosch Drill Repair. Disassembled trigger. a button with a speed regulator.

Bosch Drill Repair. Disassembled trigger. button

I do not know how to help the reader. Can someone share their experience?

I suggest to read a book, which describes various curious inventions: Otto Petrik, Curiosities of technics, Budapest 1985, 150 pp, ill.

Using the drill as a machine tool

Sample diagram of drill speed regulator.

The hand drill can be used unconventionally. It is the basis for a variety of machines: drilling, grinding, circular and others. In these machines the speed control function is very important. Most household drills have the RPM controlled by the start button on the machine. The harder it is pushed, the higher the rpm. But they are fixed only at the maximum values. This can be a significant disadvantage in most cases.

Repair of Button with Speed Regulator

Diagram of the speed regulator for a microdrill.

Button repair is a rather complicated process that requires certain skills. When you open the case, some parts may just fall out and get lost. That’s why you have to be very careful. In case of malfunction the triac is usually defective. It is a very inexpensive part. Disassembly and repair proceed in the following order:

  • Disassemble the body of the button.
  • Rinse and clean the insides.
  • Remove the board and the circuitry on it.
  • Remove the burnt part.
  • Solder a new part.

To disassemble the body is very simple. You need to bend the sides and remove the cover from the latches. You have to be careful not to lose the two springs, which can pop out. It is recommended to clean and wipe the insides with alcohol. The copper square shaped contact pins slide out of their grooves and the board is easy to remove. A burnt triac is usually clearly visible. It remains to unsolder it and solder a new part in its place. Assembly of the regulator is performed in reverse order.

The device and principle of operation of an electric drill

An electric drill is a sought-after construction and installation tool that performs drilling work. This is not the end of the product range. Thanks to the mass of attachments, the tool can perform a whole range of functions, from stirring construction mixtures, polishing and ending with the sharpening of drills. In this article, the master plumber will dissect the device and principle of operation of an electric drill.

Every good owner has a set of home tools that he needs to carry out repair and construction work at home, as well as in the cottage and outdoor areas. Someone buys only the most necessary tools. and someone buys up everything in a construction store. In any case, the drill is always in the arsenal of the home craftsman, because without this tool, many works do not seem possible.

speed, your, drill

The first electric drills began to appear immediately after the invention of the electric motor. These machines have been employed in a variety of industries (mining, medicine) since the 1860s. As electric motors improved, “tool” versions of electric drills began to appear in the 1880s, which were used in factories and shipyards.

In technical terms, an electric drill is a portable tool that is used to drill holes in walls and other horizontal and vertical surfaces. In addition to its basic function, the drill is often used as an electric screwdriver or construction mixer.

The principle of the drill is that the electric motor transmits the torque through a gearbox to the chuck, which fixes the drill. Thanks to the use of a speed-reducing mechanism, the drill rotates a little slower than the motor itself, but with increased force, so it does not stop when resistance is encountered.

In principle, all drills have the same design. all nodes and parts are shown in the photo. Impact models have additional stationary ratchets that interact with each other to make the drill progressive-impact movements for drilling particularly strong walls of reinforced concrete.

The principle of operation is quite simple: by pressing the start button, the user makes the current available to the brushes of the electric motor, which unwind the motor rotor to the necessary speed for operation. The torque is transmitted through the spindle to the gearbox. it ensures the rotation of the chuck with a drill clamped in a special device. The result of this interaction is a variety of materials that can be drilled.

A manifold motor has three main parts: the stator, rotor, and graphite brushes.

As a rule it is made of special kinds of electro-technical steel having rather high degree of magnetic permeability. Structurally, it looks like a cylinder with slots, where the winding of copper wire is placed. there are two of them and they are facing each other. The stator is rigidly mounted in the drill body.

It is called the rotor because it is in permanent rotation when the tool is running. The armature is a shaft with a pressed-in core of similar steel to the stator. Along the entire length of the rotor, special grooves are made at the same distance, in which the winding is placed. They are wound from solid copper wire and the leads are fastened to the collector plates. The whole armature is divided into segments, its collector is rigidly mounted on the shaft shank, the whole structure rotates during operation on bearings mounted on both sides of the shaft.

Special guides in the stator housing move the brushes with built-in springs when the motor is running. they transfer the voltage to the rotor, so there is constant sparking between them and the armature housing, indicating that all is normal. In the process of operation the body of brushes, made of pressed graphite, wears out because of the constant friction, so they are periodically inspected and replaced.