How to mark the holes on the flange. Division of a circle into any number of equal parts. Marking and punching centers before drilling holes

The process of marking metal consists in applying markings (lines or scratches) to the prepared material. These markings will define the boundaries (contours) of the flange blanks, that is, future parts that will need to be processed in the future.

The surface of the material must be prepared before marking. The choice of workpiece must be carefully approached. It must be checked for scratches, holes, chips, cracks, and so on. Such a blank is not completely suitable for the manufacture of parts, but if there is a clean part, then it can be used for a future blank. Now preparation begins: cleaning from rust, from scale, cleaning from dirt and other manipulations. As a cleaning agent, brushes made of metal are used, and construction sandpaper. Next, the main marks are applied, and with the help of special tool a complete marking of the contours of the future part is done.

After defining the boundaries, the workpiece or the future part is painted. They are usually painted with a solution of alcohol varnish (shellac) or a solution of copper sulphate. In factories in special industrial premises industrial means are used. One of these is a specially prepared product from a solution of chalk and wood glue. Fuchsin (a special dye made from greenish crystals with a metallic sheen) is added to a solution of alcohol varnish (shellac) to give color. For uniform distribution, it is better to apply the solution mutually perpendicularly, and dip the brush into the paint only with the tip.

If the flanges of GOST 12821 are made of steel, then it is necessary to prepare a solution for painting with a different composition. For example, a solution with the addition of copper sulfate. But it must be taken into account that blue vitriol refers to poisonous chemicals therefore, special care must be taken and a respirator mask and gloves must be worn. When the surface is completely dry, start marking. When marking, the following rules are observed: horizontal lines are made first, vertical lines are made second, then lines are applied at an angle. The final step will be the application of rounded lines and arcs. For straight lines, a scriber is used. The scriber leans in the direction where its movement will be directed, and it is deflected from the ruler in the opposite direction. When applying the risk, the angle of inclination of the scriber does not change. The line is drawn out only once, so if it is not very noticeable, then the risk is covered with paint, they wait for the paint to dry, and they do this process again.

GOST 12821 flanges made of aluminum sheet are marked with a simple pencil. Use squares, protractor and compasses. A center punch is also used, they determine the center for drilling holes, which is calculated using measuring instruments. Kerner must be taken in left hand 3 fingers and set with the point in the center of the hole. In the process, it is tilted and pressed to the center, and then transferred to vertical position and lightly strike vertically downwards with a hammer. The hammer is taken weighing about 200 grams.

Today in the post I post several pictures of ships and schemes for them for embroidery with isothread (pictures are clickable).

Initially, the second sailboat was made on carnations. And since the carnation has a certain thickness, it turns out that two threads depart from each. Plus, layering one sail on the second. As a result, a certain effect of splitting the image appears in the eyes. If you embroider the ship on cardboard, I think it will look more attractive.
The second and third boats are somewhat easier to embroider than the first. Each of the sails has a central point (on the underside of the sail) from which rays extend to points along the perimeter of the sail.
Joke:
- Do you have threads?
- There is.
- And the harsh ones?
- It's just a nightmare! I'm afraid to come!

In December, in a couple of weeks, the blog turns a year old. It's scary to think - it's been a whole year already! When I started blogging, I had a good stock if I had a dozen topics for future posts, and there were no written posts in drafts at all, which, from the point of view of serious blogging, was no good. It turned out, I acted according to the principle - First we get involved, and then we'll see. And here's what happened. To date, my readership is represented by 58 countries. But I would really like to know more about who comes to my blog and for what purpose, how the blog materials are used. This is very important so that I can evaluate the usefulness of filling the pages and, next year, at a new round of development, take into account the wishes of a respected audience (in zagnulJ). I developed a questionnaire consisting of 10 questions with a multi-choice, i. You must select one of the suggested answers. If there is something that you would like to express, but it was not included in the list of questions, write to me by e-mail or in the comments to this post ...

1. Set the outline on the edge of the workpiece and fix it at a distance equal to the distance to the bend or cut.

2. Draw a line from the edge of the sheet (draw the outline parallel to the plane of the sheet) (Fig. 24).

Marking and punching centers before drilling holes

1. Mark the centers of the holes of the upper seam in a checkerboard pattern according to drawing 1 (Fig. 25).

2. Punch the intersection points (Fig. 26).

The centers of the holes are punched before drilling sheets, parts and assemblies.

Marking with a thickness gauge

1. Mark a square on the end and on the side surface of a round steel billet (Fig. 27).

2. Place the steel bead on the prism.

3. Mark the axes:

1) install the thickness gauge arbitrarily, fix it in draw on the end of the roller short line(Fig. 28);

2) turn the roller 180 ° and, without moving the scriber, draw a short line parallel to the first one on the end of the roller

3) halve the distance between two parallel lines, set the thickness gauge along the marked middle and draw through the middle center line(Fig. 30);

4) turn the roller by 90 °, align the vertical position with a square and, without moving the thickness gauge scriber after drawing the first center line, draw the second center line

rice. 30. (Fig. 31 and 32);

5) mark the center and outline a circle with a diameter of 11 mm (Fig. 33).

1. Mark the sides of the square at the end and on the side surfaces (Fig. 34 and 35).

4. Mark the length of the square (Fig. 36).

e) Marking when assembling units and installing them on an aircraft

Marking is done not only in the manufacture of parts, applying the outlines (contours) of parts to the material, marking the places of holes, etc., but also when installing parts and assemblies in place during their assembly.

To determine the location of parts and assemblies on the machine, it is necessary to measure and mark these parts and assemblies on the machine itself in accordance with the dimensions indicated in the drawing.

A. Marking the position of the clamp on the side member

It is required to install clamp A on the side member B. According to the drawing, the middle of the clamp should be at a distance

175 mm from axle vertical rack in the fuselage; clamp length - 36 mm, pipe diameter B is 20 mm (Fig. 37).

1. Determine the distance from the end of the collar closest to pipe B to the nearest point on that pipe. This distance must be less than 175 mm by half the length of the clamp and half the diameter of the pipe, i.e. less by

36/2 + 20/2 = 56/2 = 28 mm.

Then the distance from the end of the clamp to pipe B will be 175 - 28 = 147 mm.

2. Attach a meter to the side member so that its beginning rests against pipe B.

3. Make a mark with a pencil on the side member against the division of 147 mm.

4. Put a clamp on the side member so that its end, directed towards the pipe B, coincides with the mark.

In this case, the middle of the clamp A should be at a distance of 175 mm from the axis of the pipe B.

B, Marking the position of the clamp on the side member using a special template

1. Attach the cutout of the ruler of template A to the post and press the bracket of template B to the side member (Fig. 38).

2. Draw a line along the edge of the bracket to determine the location of the clamp on the side member.

B. Marking the axis of the fuselage on its skin

Draw the longitudinal axis of the fuselage on its skin. According to the drawing, the upper side of the spar in the area from the first to the third frame is parallel to the fuselage axis and is located at a distance of 490 mm from it (Fig. 39).

a) Place the heel of the square with a long shelf on the upper side of the spar so that the shelf of the square lies on outside plywood sheathing, closer to the first frame.

b) Draw a line along the pole with a pencil.

c) Draw a line in the same way at the third frame.

d) Measure along the drawn lines from the upper side of the upper side member 490 mm each and make marks.

e) Draw a line through these marks, which will be the axis of the fuselage (the fuselage tapers towards the tail along a curve and therefore

The center line can only be drawn with three help of a flexible metal ruler or a flexible wooden ruler).

The first worker applies one end of the ruler to the mark at the first frame, the second worker, located at the tail, firmly presses the ruler to the fuselage, and the third worker monitors

so that the ruler coincides with the second mark and instructs the second worker to raise or lower the end of the ruler. Supporting the ruler with his left hand, the third worker draws an axis with a pencil.

f) Mark holes or necessary points on the squares; squares have holes or cutouts on the shelf to mark the necessary points.

Basic markup rules

1. When marking parts and assemblies during assembly, remember that marking is always carried out from such points and surfaces, the position of which is quite definite on the plane. The main base for marking on an aircraft is the longitudinal axis of the fuselage or points and lines associated with it by certain dimensions.

2. When starting to markup, draw up a plan for yourself, that is, establish in what sequence to markup and with what tool.

3. When drawing lines, hold the pencil or scriber a little obliquely so that the line closely adjoins the ruler or square, which must be firmly supported with the left hand.

4. For marking, use a simple, not chemical pencil. When applying scratches with a scriber, you can scratch the material, which will degrade the quality of the product. So, for example, scratches on duralumin, which violate the integrity of the outer layer of the metal, reduce its strength and resistance to corrosion. Chemical pencil spoils duralumin, causing corrosion.

5. Remember that markup is much easier and faster if you use templates.

6. To speed up the marking of long lines, when great accuracy is not required, instead of drawing them, take a hinted thin cord and beat off the lines with it.

Marking parts with reedging

To obtain a primary skill in spatial marking with re-edging, hollow parts are used, for example, pipes, cases of feed boxes, gearboxes, aprons of lathes, etc.

This exercise looks at an example of how to mark out flanges on a nozzle that has flanges in different planes. It is desirable that the planes of the flanges are pre-machined.

1. They study the drawing, determine the correspondence of the workpiece to the dimensions in the drawing. The internal holes are taken as the base.

2. Bars are installed in each hole.
3. The surfaces of the flanges are painted with a solution of vitriol or varnished.

Installation and alignment of the nozzle on the marking plate (first position) are as follows.

1. The branch pipe is installed on two prisms so that the middle flange rests on the jack (Fig. 281, a).

2. Verify the position of the part on the marking plate. For this:

A) with the help of wedges and linings, they achieve a horizontal position of the hole in relation to the plate; the check is carried out with a thickness gauge along the upper or lower edge of the hole;

B) in the same way set in horizontal position middle flange hole;

C) finally check the horizontality of the holes on all flanges with a thickness gauge;

D) with a square with a heel, the perpendicularity of all planes of the flanges to the plane of the marking plate is checked.

Marking and applying risks in the first position is as follows.

1. Measure the diameter of the flange hole 2 with a caliper.

2. Vertical double ruler, based on hole diameter, determine the vertical dimension to the center line.

Fig 281. Marking the branch pipe with reedging: first position; b - second position

3. Apply this size marks A - B on all surfaces of the flanges.

4. On the horizontal risk of the middle flange, mark the center point with a compass.

5. Through the center point, draw a vertical risk V - D with a square.

Installation and alignment of the part after re-edging (second position) are as follows.

1. Unfold (turn over) the part at an angle of 90 ° (Fig. 281, b).

2. Verify the position of the part on the plate. For this:

A) apply a square to the plane of the flange so that the previously applied risk A - B is located perpendicular to the plane of the plate along the square;

B) repeat the method of checking the horizontal position of the hole on the plate with a thickness gauge.

Marking and drawing risks in the second position are carried out as follows.

1. Based on the diameter of the hole, determine the size along the vertical line to the center mark.

2. On the planes of the two flanges, mutually perpendicular risks are drawn, where the intersection points will be the centers of the holes.

3. Pierce the centers of the holes.

4. Compasses check the correct location of the center points in relation to the edges of the hole.

5. With a radius, circles are drawn on the planes of each flange (Fig. 282).

6. Using a table of chords or geometrically, the circle is divided into a given number of parts.

7. Pierce the centers of the holes for the bolted connection.

8. Two circles are drawn for holes: one with a radius R2 - d.12 and the other (control) with a radius R2 + 1 mm.

9. Pierce the risks of the main circles.

K category: Plumbing work

Planar marking

Planar marking consists in drawing on the material or workpiece contour lines (rises) - parallel and perpendicular, circles, arcs, angles, various geometric shapes according to given sizes or contours according to templates. contour lines applied in the form of continuous risks. To preserve traces of risks until the end of processing, small depressions are often applied to the risks using a center punch, located close to each other, or a control risk is applied next to the marking risk. Risks should be subtle and clear.

The following tools are used to mark, measure and verify the correctness of the manufacture of products; ruler, square, compasses, calipers, calipers, inside gauge, scale and curved rulers, protractor, scriber, center punch, marking plate and templates.

On fig. 1 shows the simplest marking and measuring tools, as well as measurement techniques.

The measurement accuracy with a millimeter scale ruler, calipers and inside gauge is 0.5 mm, with a caliper - 0.1 mm. For correct markup it is necessary that the tool be accurate and serviceable.

The correctness of the ruler is checked as follows. Draw a line along the ruler, shift the ruler on the other side of the line without turning it over, align the edge of the ruler with the drawn line, which in the correct ruler should coincide at all points with the drawn line.

The straightness of the sides of the square is checked with an accurate ruler. To check the correctness right angle the square is applied with one side to the ruler, and a vertical line is drawn on the other side. Then the square is shifted to the other side of the drawn line so that its top remains at the same point. The square is applied close to the ruler and a second vertical line is drawn. If the square is correct, both lines should match.

The correctness of the applied divisions on a ruler or meter is checked as follows: the legs of the compass are placed 2-3 cm and rearranged along the entire length of the ruler or meter.

Rice. 1. Marking and measuring tool and measurement techniques: a - scale bar; b - methods of measuring with a scale ruler; c - locksmith square and methods for checking the correctness of the angle, d - caliper and methods for measuring them; 1.9 - fixed and movable jaws for external measurement, 2.4 - jaws for internal measurement, 3 - inner size parts, 5 - screw for fixing the frame, 6 - movable frame, 7 - bar with millimeter division, 8 - vernier, 10 - outer dimension details, 11 - depth gauge; e - caliper and inside gauge and methods of measurement by them; e - curved ruler and methods for checking the surface to be treated with it

Steel scriber should be pointed, round section so as not to spoil the ruler and square. When drawing marks, the scriber should be pressed tightly against the edge of the ruler or square, slightly tilted forward. A clear thin risk should remain on the steel sheet. Brass scriber leaves a clearly visible mark on black steel.

The legs of the marking compass must be sharpened and hardened.

When marking thin sheet steel, one drawing leg should be sharply sharpened, and the other should have a slightly turned edge so as not to leave holes in the sheet steel.

When drawing circles on metal, the centers are marked with a center punch.

tricks planar markings on metal are shown in fig. 2. Parallel lines are drawn with a scriber over a square (Fig. 2, a, b).

Rice. 2. Techniques for planar marking a - drawing marks, b - drawing parade lines along the square with a scriber, c - drawing perpendicular lines with a scriber along the square, d - constructing a perpendicular line using a compass, e - constructing parallel lines using a compass, e - construction of a hexagon inscribed in a circle, g - construction of angles with a protractor, 3 - division of angles using a compass

Perpendicular lines are built using a square with one right angle.

You can lower the perpendicular from the point O to the line AB or restore the perpendicular to the line from the point M using a ruler and a square (Fig. 2, c). The ruler is aligned with the AB line, the square is tightly attached with one side to the ruler and moved along the ruler until the other side of the square is aligned with the O or M point, and then a line is drawn perpendicular to the AB line.

The perpendicular can also be restored and lowered using a compass (Fig. 2d). From point M on a straight line with an arbitrary radius, two serifs (short arcs) 1 and 2 are made. Then from points 1 and 2 with a radius, large cut 1-2, make serifs 3 and 4. The point E of the intersection of serifs S and 4 is connected to point M. The resulting line EM will be perpendicular to the line AB.

Parallel lines can be drawn using a square and a compass. To draw a VG line (Fig. 2, e) parallel to the AB line, from any two points of the AB line, for example, D and G, restore perpendicular lines using a square or a compass, on which equal segments are laid (in our case 6 cm) DE and JZ. Through points E and 3 draw a line VG, which will be parallel to the line AB.

Parallel lines can also be drawn using a ruler and square. If you move the square along the ruler, then all the lines drawn along the side of the square will be parallel to each other.

The marking of the circle on the metal is carried out using a compass, having previously marked the center O with a center punch (Fig. 2, f).

The distance drawn by the compass from the center O to any point on the circle is called the radius and is denoted by the letter R.

When marking out, it is often necessary to divide a circle into equal parts, as well as measure, build and divide angles. To divide a circle into two equal parts, it is enough to draw a diameter. To divide it into 4, 8, 16, 32 parts, first two mutually perpendicular diameters are drawn, which divide the circle into four equal parts. Then each part is divided in half, etc., and 8, 16 and 32 parts are obtained. To divide a circle into 3, 6, 12, 24 parts, etc., its radius is plotted on the circle, which fits exactly six times. By connecting these points through one, the circle is divided into three parts. Dividing the ‘/b part of the circle in half and into four parts, we get Vi2 and V24 of its parts.

Angles are measured with a protractor (Fig. 2g). With the help of a protractor, the construction of corners is most simply and correctly performed.

Angles of 90, 45, 60, 120, and 135° can also be constructed using a square, compass, and straightedge. An angle of 90 ° is built using a square and a ruler. An angle of 45° can be built by cutting a 90° angle in half. To do this, from the apex of angle A (Fig. 2, h), an arc 1 is drawn with an arbitrary radius, intersecting the sides of the corner at points C and D and the continuation of the side AG at point B. From points C and D, notches 2 and 3 are drawn with the same radius, intersecting at point D. The line connecting point D with the vertex of angle A divides the angle in half.

By drawing an angle of 45° to a 90° angle, an angle of 135° is obtained.

To construct angles of 30 and 60 degrees, you need to divide the right angle into three parts. One third of a right angle is a 30° angle and two thirds is a 60° angle.

To divide a right angle into three parts, an arc is drawn from the vertex of angle A (Fig. 2, h) intersecting the sides of the angle at points B and C. From these points, notches 4 and 5 are made on the arc with the same radius. The resulting points E and G connected to the apex of angle A. Lines EA and ZHA divide the angle into three equal parts.
Various geometric figures applied on the plane with the same marking tool: ruler, square, compass and protractor.
To speed up and simplify the planar marking of identical products, sheet steel templates are used.

A template is applied to the workpiece or material and pressed tightly so that it does not budge during marking. Lines are drawn along the contour of the template with a scriber, indicating the contours of the workpiece.

Large parts are marked on the plate, and small parts are marked in a vice.

If the product is hollow (for example, a flange), then they hammer into the hole wooden cork and a metal plate is fixed in the center of the cork, on which the center for the leg of the compass is marked with a center punch. The flange is marked as follows. The surface of the workpiece is painted with chalk, the center is marked and circles are drawn with a compass: the outer contour, the contour of the hole and the center line along the centers of the bolt holes.

Often the flanges are marked according to the template, and the holes are drilled along the conductor without marking.

It is necessary to mark accurately and carefully, since the quality of the product depends on the correct markup.

Marking tool must be stored in designated areas.