How to disassemble a watch caliper compass. Caliper - an indispensable assistant in the work

The caliper got its name due to the main element of its body - the rod, but the compass we are used to is a little far from this tool with its device. To understand a subject full of mysteries, we will try with the help of this article, consider its structure and principle of operation.

Caliper device - the main components and their purpose

The device of the caliper does not look complicated on the surface, but its parts are so compact and optimally composed that they make this device easy and convenient to use. And it can do a lot, and the measurements that are performed with its help are very important in many areas of industry and construction. When using a caliper, we get linear dimensions objects, both internal and external. And the accuracy, which in some models reaches an enviable level, makes this simple tool more and more in demand.

The purpose of the caliper is to measure the length, diameters, depths, but what provides this opportunity, we will analyze using the simplest type of this device as an example. The main node is the ruler, which is called the bar, giving part of the name to the tool. The divisions on it are usually 1 mm, and the total length is usually 15 cm, but individual models may be longer. The ruler determines the maximum size that this tool can measure.. This means that the maximum length or diameter of an object should be no more than 15 cm.

At the end of the ruler are sponges, or rather their halves, and the second halves are located on a movable frame that moves along the ruler, measuring the size of the object being examined. Sponges are internal and external, in the first incisors look outward, in the second - at each other. Therefore, the former are inserted into the object and moved apart to fix the internal geometric parameter, and the latter move apart widely, and then approach each other in order to fix the object under study among themselves. To accurately measure or transfer it to another surface, the movable frame can be fixed with a special screw located on it.

On the main ruler, we can see the integer value of the desired size, but the vernier scale, which is applied to the bottom of the frame, to be exactly under the main ruler markup, will help clarify the result. The vernier has ten divisions, each of which measures 1.9 mm, the entire scale is 1.9 cm long. These are the parameters of a conventional household caliper, on other models this ratio changes. Having found the vernier division, which coincides with any division of the main scale, you can refine the desired value to tenths of a millimeter. The use of a caliper is not limited to internal and external dimensions, you can also mark the depth of the holes, for this there is a tail that extends from the ruler. This is the depth gauge.

Caliper - classification and marking

The measuring tool caliper can be of 3 types and about 8 sizes, in any case, according to domestic regulatory documents. Moreover, when buying any precision instrument, it is important to focus on the standards by which it is made and calibrated. It is divided into types depending on the indicator of the measured value, from which we take the desired numbers. This can be vernier (ShTs), dial (ShTsK) and digital (ShTsTs) calipers. In the first case, we will have to go over both scales ourselves with our eyes, count the divisions and report the result. In the second case, we will see the numbers on a mechanical scale with a moving arrow, but in the third case, we will be shown the finished result on the display.

Within these species, subspecies can also be divided depending on the design and length of the main ruler. For example, you can divide tools by the type of material from which they are made. ShTsT-I can serve as an example of a hard alloy tool. There are differences in the arrangement of sponges or accessories. So, ShTs-I and ShTs-III differ in the location of the jaws, in the first case it is two-sided, and in the second - one-sided. But in ShTs-II there is a micrometric feed frame, which will make marking easier if you need to transfer your measurements to another plane. It makes no sense to discuss the differences in standard sizes for a long time, one has only to say that the larger the ruler, the greater the error in the values ​​obtained.

How to measure with a caliper - instructions for beginners

Most technically developed people it is intuitively clear how to use a caliper, so we briefly recall the main points.

How to measure with a caliper - step by step diagram

Step 1: Fixing the Part

First, check the tool for serviceability, to do this, reduce the sponges without a part to zero, look at the clearance, how correctly they are connected, and also look at the scale to see if the zeros on the two scales coincide. After a positive result, you can start working with the part. It is most convenient to work when the tool is in your right hand, and the part to be measured is in your left, or it is completely fixed somewhere. If you are left-handed, then the ratio is, of course, the opposite. To measure the outer dimension, spread the jaws of the caliper, place an object between them and connect them. They should rest against the edges of the part being examined. If it is hard, you can lightly squeeze the lips for a firm touch. If the part is soft, do not do this, the results will be distorted.

Effort is controlled simply, if you try to move the lips relative to the object, then they should do it reluctantly, but if you also need effort for this, then you obviously squeezed it.

Move the frame more conveniently with your thumb right hand, while holding the barbell with the rest. Check the position of the caliper relative to the object, if there are any distortions (the sponges should be at the same distance from the edge of the object on both sides), it is better to raise the structure to eye level. To see more clearly, it is better to hold the object in the plane behind the instrument with the left hand, and not in front. Now you should carefully tighten the mounting screw, index and thumb, while the rest should continue to hold the bar. When the value is fixed, the part can be put aside and proceed to the study of the next step, how to measure the resulting number with a caliper.

Step 2: Remove value

It is best to read the readings also at eye level. First of all, we write down the value of the main scale, i.e. integer. To do this, we are looking for a stroke on the main rod, which is closest to the zero value of the vernier, this is an integer number of millimeters. You can remember, or you can mark it somewhere on a draft. Now we are looking for a stroke on the vernier that is closest to its zero, but also exactly coincides with some division on the bar. Its serial number should be multiplied by the division value of the vernier used (usually 0.1 mm). If you are not sure that you know this value, look in the passport of this caliper.

Now the matter is small, you just need to sum up these numbers, and the result is ready. For example, on the bar you had a value of 35 mm, and on the vernier you counted 4 more divisions, then general meaning equals 35.4 mm (3.54 cm). After work, the tool is wiped (degreased), the sponges are slightly pushed apart (by a couple of mm), the clamp is loosened and placed in a case. If storage is planned for a long time, then you can lubricate it against corrosion.

The main defects of the caliper tool that can be eliminated during repair are errors in the divisions of the vernier, curvature of the guide edge of the rod, pitching and skew of the frame, non-parallelism of the measuring surfaces, their damage, wear of the base, etc.

Checking the correctness of the ribs of the rod and the measuring planes of the jaws is carried out using blocks of end measures clamped between the measuring planes when the frame is moved every 10 mm of the length of the rod. In any position of the frame on the rod, the pressing force of the measuring planes on the block must be the same on the entire plane of the measure. If the touch of the measuring planes with any block of sharp and blunt jaws is different in different positions of the frame, this means that the rod is bent. If, at any position of the frame, the solution of sharp jaws is less than the solution of blunt ones, or vice versa, then the caliper jaws are faulty.

To fix the rod, its working edge is checked for paint on a test plate, and the bulges are removed with a personal file or fine-tuning. Then the second rib of the rod is made strictly parallel to the working rib, also with the help of a file or finishing. After that, the measuring planes of the sponges are finished.

To finish them, the caliper is fixed in a vise with lead jaws (Fig. 177, a). Finishing is carried out with a cast-iron lap (Fig. 177, b). The lap is clamped between the jaws, for which the frame is brought close to the lap and the micrometric feed of the frame is fixed. The lapping must without special efforts move back and forth between the lips.

Fig. 177.
Fine-tuning of the jaws of the caliper.

Sponge skew is easy to install. To do this, it is enough to clamp a block of end measures between the jaws and if one of the sides of the block moves away from one of the sides of the jaws, then the skew is set. The misalignment of the working planes of the sponges with respect to the rod is corrected by grinding on a surface grinder. After grinding, both sharp and blunt sponges are polished with a coarse GOI paste and polished with glass laps with a thin paste. The finishing of the jaws is considered complete if the lapping passes with the same force at both ends.

After finishing the jaws, the coincidence of the zero division of the rod with the zero division of the vernier is checked. To do this, the jaws tightly shift and clamp the movable frame of the caliper. After making sure that there is no gap between the jaws, they release the screws that fasten the frame with the vernier. Then the frame with the vernier is moved in one direction or another so that the first and last division of the vernier coincides exactly with the first and other corresponding division of the bar. Also pay attention to the fact that the second and third risks from the beginning of the vernier are located equally with the second and third risks from the end of the vernier in relation to the corresponding risks on the bar. After that, the screws are fixed and, after checking once again the coincidence of the divisions, the installation of the vernier is considered complete. In the event that when installing the vernier it is not possible to move it due to the gap in the screw holes, the holes are expanded with a needle file.

Very often there is a breakdown of the jaws of the caliper. When correcting this defect, one of the three decisions depicted in FIG. 178: shorten the length of the jaws (Fig. 178, a), remove one pair of jaws (Fig. 178.6) or make a cutout to insert a new sponge (Fig. 178, c). Sometimes a new one is welded in place of a broken sponge.

Fig. 178.
Repair and restoration of caliper sponges.

The correction of defects in light-weight calipers is carried out mainly by straightening, followed by fine-tuning of the measuring planes. So, if even when the working surfaces of the jaws are worn, the zero stroke of the vernier does not coincide with the zero stroke of the rod, then after fine-tuning the measuring planes, this error will be even greater.

Therefore, it is corrected by straightening. A fixed sponge is placed on a hardened bar, fixed in a vise, and hit on it in place a (Fig. 179) so that its spout goes down. Impacts are made on both sides of the caliper. The same is done with the sponge of the movable frame, hitting it in place b. The sharp ends of the sponges are straightened in places a and b.

Fig. 179.
Repair of a lightweight caliper (arrows show the places of impacts during straightening).

After straightening, the measuring planes are sawn off and the measuring planes are brought to coincide with the divisions of the rod and the vernier, and finally, the nicks are cleaned and all planes are polished with fine sandpaper.

Correction of the base of the height gauge is carried out by lapping on the lapping plate using grinding powders.

No plumbing work is complete without measuring one or another detail. Many products or some operations in the process of execution require control. One of the most universal means is a caliper (shts, shtangel).

This tool is necessary not only in the engineering industry, but also in the household when repairing a car, household appliances. With it, you can measure linear dimensions, for example, bearing diameters. This is a handy and accurate instrument.

Many in their lives have faced the need to use this meter, but most do not know how to use it correctly. How to make accurate measurements with this device?

For proper use and understanding, you must familiarize yourself with the device. All calipers, regardless of their type, class and measurement accuracy, consist of the following elements:

There are calipers different types. Depending on the measurement limit: shts-1, shts-2, etc.

By layout type:

• nonius (ordinary, most common and cheapest);
• electronic (on the moving part - a liquid crystal display showing the measurement results);
• pointer or dial (they have a “clock” mechanism on the moving part).

In mechanical engineering and aircraft building there are special rods. They differ from ordinary shts in special sponges.

Proper use of calipers

Before starting work, it is necessary to determine the integrity and serviceability of the measuring tool. The lower jaws should be tightly closed without gaps, notches and distortions.

In this position zero marks the rod and vernier must match exactly. There should be no dirt, corrosion, nicks on the surface of the barbell.

If necessary, it is necessary to wipe with a clean rag not only the barbell, but also the measured surface, otherwise this may affect the measurement error. Next, let's take a closer look at how to measure correctly with a caliper.

How to use vernier caliper 0.1 mm, shts-1

The bar must be taken in the right hand, spread the sponges to the required length with the thumb (there is a corrugated protrusion on the movable bar for this). Sponges to the measured surface should fit snugly, without distortions.

Strong force is not needed. The contact of the jaws should be light and completely adjacent. Next, we look at the indicators. The first division of the vernier shows, say, more than 7 mm, but does not reach 8. So, we are looking for a match on the vernier scale. Let's assume that we found a match at the fifth division. So the size is 7.5 mm.

When measuring, it is not necessary to tighten the fixing screw too much, as this can knock down the true size. You need to correct the backlash at the beginning of work, if necessary. A rigidly fixed body with a nonius is necessary when marking.

To measure the depth, it is necessary to bring the end of the gauge to the edge of the part. The butt should fit snugly, without distortion. With the thumb of the right hand, it is necessary to bring the depth gauge into the hole until it stops against the wall. The tip of the device should lightly touch the bottom. In this case, extrusion of the end of the rod should not be allowed. If necessary, you can fix the movable bar with a screw and read the readings, as with other types of measurement.

If you follow these tips, the measurement accuracy will increase significantly. They are suitable for all types of SC.

Care and storage rules

After work, the caliper must be wiped, cleaned of dust and dirt. It is best to store in the original box with which the device is sold.

It is better to keep the device in a dry and dark place, protecting it from falls and mechanical impact. Careful and careful handling will allow you to operate the measuring tool for many years.

It just so happened (at least for the author) that the accuracy of measurements is made: with a ruler up to centimeters and a half, with a caliper up to millimeters, but tenths and hundredths of a millimeter are “caught” exclusively with a micrometer. What prevents using a caliper to measure tenths of a millimeter, because it is intended for this, and it will be difficult to answer “offhand”. Often, even those who know the device of this measuring tool will be careful not to indicate the size fixed by a caliper to within tens - because the scale (vernier) is “responsible” for determining tenths of a millimeter. I admit that it is for this reason that part of the calipers began to be produced equipped with a dial scale and even equipped with an electronic display (electronic).

And what prevents you from upgrading the caliper already in use and thereby bringing the accuracy of its measurements closer to those of the dial and, for example, equipping it with a magnifying glass? I sat down to the computer and began to draw a device that had already visited the imagination.

Refinement scheme

The sketch was made in a section, where the number:

• 1 - the caliper bar is indicated
• 2 - movable caliper frame
• 3 - holder frame, it is installed on a movable frame
• 4 - screw fixing the frame to the frame
• 5 - a screw that secures a frame with a magnifying glass to the frame
• 6 - magnifying glass frame
• 7 - spring pressing the frame to the head of the fixing screw
• 8 - magnifying glass

In accordance with the finished sketch, I collected the most suitable components of the future holder “by the bottom of the barrel”.

In a textolite cube (in the past, some part of the body electronic device, and in the future frame of the holder) increased the existing groove with a file to the dimensions corresponding to the movable frame of the caliper and drilled a hole with a diameter of 3 mm in the center for the fastening screw.

On the side done threaded hole M4 screw fixing frame with magnifying glass. With the end of the manufacture of the frame, labor-intensive operations that require precision and careful fitting end.

A frame was made from a piece of soft plastic (in addition to the existing one). There are two holes drilled in the plastic plate. The smaller one is for the mounting screw of the frame, the larger one is for the existing frame (into which it is screwed along the thread, which makes it possible to adjust the sharpness).

Device assembled, according to the drawing, form. I didn’t specially cut the thread in the additional frame, it was made by the thread of the old (metal) frame during the first screwing. For this, a soft plastic plate was selected, and the hole was made 0.5 mm smaller than necessary. It is clearly seen that the risks of the vernier (the name of the scale for determining tenths of a mm) are increased to the size of a more comfortable observation. This makes it possible to confidently determine the measured size with an accuracy of "tens". And even more - now you can easily distinguish a wire with a size of 0.85 mm from 0.80 mm using measurement.

Procedure for taking caliper readings

1. count the number of whole millimeters, for this they find on the scale of the rod the stroke closest to the left to the zero stroke of the vernier;
2. fractions of a millimeter are counted, for this, a stroke is found on the vernier scale that is closest to zero division and coincides with the stroke of the rod scale - its serial number will mean the number of tenths of a millimeter;
3. add up the number of whole millimeters and fractions.

The fixture is easy to install and remove and can only be used when needed. Project author - Babay from Barnaula.

Discuss the article UPGRADE THE CALIPERS

The caliper is a universal measuring tool. It is intended for high precision measurements. It can be used to identify both external and inner dimensions details, hole depth, etc. It is one of the most common tools in the tech industry and is easy to use. It is used at the level with things like . Due to its mechanical structure, the device has practically no limits on its service life, since only deformations can bring it out of working condition. Despite the prevalence, many people do not know how to use a caliper.

Measurement with a caliper is used both in the industrial sector and in the private sector, since the device takes up relatively little space. One of characteristic features here is the vernier scale, which allows you to make measurements down to tenths of a millimeter. Design features allow you to fix the measured part, and both with inside, and from the outside, to reduce the likelihood of errors. No special training is required for use here and you can start working almost immediately.

The device and principle of operation of the caliper

The tool got its name due to the presence of a rod on which the main scale is applied. Nonius refers to an additional scale that helps to keep track of tenths or hundredths of millimeters, if the measurement requires it. The device contains the following basic elements:

1. Barbell;
2. moving frame;
3. The main scale located on the bar;
4. Sponges measurements of the inside;
5. Sponges measure the outside;
6. Depth gauge;
7. Vernier;
8. The screw that secures the frame.

In some models, there is a double scale, which can show calculations not only in millimeters, but also in inches. Other parts of the caliper generally remain the same.

During the movement of the moving parts, the part with the control division also moves, which will show the number of millimeters. Regardless of whether you want to measure external dimensions, internal or depth, the movements will be the same, only the control limit gauge is different. For this, there is a depth gauge that rests on the bottom of the object being measured. For ordinary sizes, the part must be fixed in the inner or outer jaws. After determining the value on the main scale, you can use the vernier for more accurate readings.

Rules for using a caliper

• During the measurement of the part, in no case should you allow the situation so that the jaws of the caliper are warped. After they reach the desired position, they need to be fixed with a locking screw in order to avoid the above troubles.
• While reading the readings of the device, you should keep it in front of your eyes directly.
• When using the device, safety rules must be observed, since the ends of the sponges are quite sharp and can cause injury.
• It should be stored in places where sawdust, shavings, water, dust and other negative factors do not fall. At the same time, you should not place it far from the workplace, as it is often used.
• After work and before starting it, the tool should be wiped with a clean cloth.

How to measure with a caliper

Before you measure with a caliper, you need to familiarize yourself with the basic rules.

• Measurement of external surfaces. In order to get information about external dimensions product, it needs to be fixed in the lower jaws of the tool. To do this, it is required to dilute it a little more than the measured workpiece itself, and then bring the lips to the stop. After that, you can take readings on the main and additional scales.
• Measurement internal surfaces. For this operation, the tool should be moved to the zero position, after which the jaws for internal measurement should be placed in the workpiece, parallel to the plane to be measured. Next, you should spread them all the way, which will help fix them in one position and avoid large errors. This is also suitable for determining the diameter.
• Depth measurement. Here the main part is the depth gauge. Measurement with a caliper is carried out by resting the end of the tool at one end of the part and immersing the depth gauge at the other. When he rests or reaches desired point, then you can take readings on the main and additional scales, since the vernier is still relevant here.
• How to markup. The marking is applied with direct risks from the base edges of the tool, located in parallel, or the surface of the workpiece itself. They also make serifs and can draw circles.

photo: external and internal surface measurement with a caliper

photo: measuring depth with a caliper

The main problem in understanding how to use a caliper is determining the exact result, as well as using the additional functions of the device. The situation is most simple and understandable with external dimensions, but the principle of removal is almost the same everywhere, therefore, you should learn how to use two scales. The first one, which is also the main one, shows whole fractions of a millimeter. Regardless of whether you are using a depth gauge, outer or inner jaws, all three parts move according to the measured distance. In order not to bring down the readings during the measurement, when everything reaches the control limit point, the device is fixed.

a) 6.45 mm; b) 1.65 mm

After that, it can be removed from the workpiece and brought closer to you. In this case, the readings remain the same as at the time of measurement. On the division bar, the divisions are immediately visible and the number of whole millimeters is immediately visible, in order to determine in more detail, you should use the vernier. It has ten divisions, each of which corresponds to a fraction of the whole. If the first division coincides with the value of the line on the main scale, then an even value is obtained. If the second division coincides with any line, then 0.1 should be added to the resulting integer value. To the third - 0.2, the fourth - 0.3 and so on.

There are verniers that show hundredths of a millimeter. The principle of measurement in them is very similar. The main thing is that the fixing element is always in working order, otherwise it will not be possible to obtain accurate data, since the position of the measuring device will constantly go astray.

How to properly store the tool

Knowing how to use a caliper is not enough, as you need to know the rules for storing and caring for the tool. It is best to store the instrument in the case it comes in. In any case, it should be a dark, dry place where dust, sawdust and other objects do not get in. Given that all models are made of metal, contact with moisture and accumulation of condensate are undesirable. Do not allow impacts and scratches, which can deform the instrument and reduce measurement accuracy. Wipe down with a dry cloth after each use. Careful handling allows you to use it for many years and even decades.

photo: storage of calipers in a case

How to use a caliper: Video