Foil braiding of the canopy of a model airplane. Windshields for airplanes and helicopters to order. Windshields for airplanes and helicopters: glazing of combat aircraft

Hello, dear and beginning modelers.

While reading the articles, I noticed that many modellers have problems making cockpits for their models. Often the cabins in the photo are either missing, or cut out from a bottle, and do not have a very aesthetic appearance. Modellers do not want to make a mold for the manufacture of this very cabin, considering this work to be labor-intensive and not necessary for the manufacture of one model. I want to convince you of the opposite - everything is very simple. And it's not expensive at all.

We will need: a hair dryer, a pine block, a hacksaw, a plane and an empty plastic bottle.
We start by making templates for the future form. First we make the template for the top part.

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Next is a side view template.
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Well, and of course, a template for the front and back of our future form. We place these templates at angles according to the side view.
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We're done with the templates, let's start making the mold.
We take a block, or maybe a package of boards connected with screws or glue, and transfer our side view onto it. Cut off the excess.
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We transfer the front and rear views to the corresponding planes.
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For ease of work, we attach a block to the bottom of the mold. We clamp it in a vice and use a plane to remove all excess.
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Our form is almost ready, all that remains is to process it with sandpaper. We spent two hours on everything.
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It's all about the bottle. I advise you to use blue or colored ones - transparent ones look worse. We stuff our form into a bottle and heat it with a hairdryer. If necessary, secure the bottle to the mold with screws.
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Cut it out and try it on.

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Everything fits. We secure the cabin with aluminum tape. Using a thin tube we imitate rivets.
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As I said, it's simple.
Good luck to everyone in the buildings and flights.

A beautiful transparent canopy of a model airplane without a “vacuum”? - Easily!

Why make your own glazing for a model airplane?

High-quality glazing of the cockpit and other transparent parts in an airplane model plays a vital role in the visual perception of the finished model - after all, the canopy of a fighter plane or the glass of the pilot's cockpit of an airliner is most often the first thing the viewer's gaze stops on (as in communicating with a person, his eyes are the first thing what the interlocutor's gaze stops at). Therefore, poor-quality glazing can immediately set a lower level of assessment of the model, which is difficult to correct with an elegantly executed chassis or many small details inside the cabin - which, moreover, will also be difficult to see through a cloudy canopy.

To the cardboard models produced by leading publishing houses, as an optional addition, ready-made lanterns and other glazing parts are increasingly being offered, which can be purchased without the hassle of making them yourself. However, firstly, ready-made glazing parts are not offered for all models available for sale, and secondly, many models are offered for assembly in an “electronic” version for self-printing - in this case, count on the opportunity to purchase ready-made glazing parts for the model It’s not necessary at all.

As a rule, a cardboard model includes patterns of glazing parts. These patterns allow you to make a cockpit canopy or parts of it from pieces of transparent film. It is usually possible to make a faceted canopy in this way, consisting of flat glass or single-curvature glass (such as that of the German Bf.109 fighter), and it looks no worse than the real thing:

However, if the canopy or its parts are formed by surfaces of double curvature (such as the convex canopy of the American P-51D fighter), it will no longer be possible to make a believable canopy from a flat film: noticeable cuts and joints of flat sections of the film will spoil its appearance and make it unattractive and inadequate faceted shape:

If there is no opportunity or desire to purchase a ready-made lantern for the model, and if the glazing patterns included with the model for cutting out of flat transparent film do not allow you to get a beautiful lantern, all that remains is to make it yourself - this is what I usually do.

Hot hug method

The only acceptable and accessible home method for making a transparent lantern from a polymer film is to heat the film to a softened state, in which the film easily changes shape, but still remains a film (that is, does not melt) and then give it the desired shape. To give the film the desired shape, a pre-made punch - a “blank” - is used, which has the exact shape of a lantern. At the same time, there are two ways to give the film the desired shape:

• usage vacuum chamber(see, for example, the website of one of the well-known manufacturers of vacuum equipment and the illustrations on it);
• simply covering the “blank” (punch) with heated film, the so-called "hot tight".

The first method is universal, but requires a vacuum chamber, the design of which is relatively simple, but which requires skillful handling. The versatility of the “vacuum” method lies in the fact that it allows you to cover a punch of almost any shape with a heated film (except, perhaps, a closed one), including those with concavities, on which the heated film will lie being “sucked” by the vacuum created by the film connected to the camera. hood.

The second method is not so universal - it does not allow the heated film to be shaped with concavities, since it does not use air rarefaction (vacuum) and there is no way to “press” the heated film into the concavity of the punch. In a nutshell, the method consists of covering a punch that defines the shape of the required transparent part with a heated transparent film so that the film fits tightly to the punch over its entire surface. The cooled film retains the shape of the punch. In this case, a vacuum chamber or any other means is not required that presses the film against the punch during the cooling process - the film fits around the punch solely due to its own tension. The method is suitable only for convex shapes and, accordingly, for fitting convex punches - more precisely, not necessarily convex, but necessarily non-concave - without sections of negative curvature in two directions simultaneously.

I often practice this method and in this article I offer a description of the process of making a lantern using the “hot-fitting” method the way I do it.

So, I'm building a model and I need a convex canopy for it. Usually this is a model on a scale of 1:32 or 1:33, the canopy has quite “tangible” dimensions - from 1 cm in each dimension (the “smallest” are the canopies of the Soviet Yaks and MiGs of the war years, but they are not less than 1 cm in these scales, counting from the “rails”). The sequence of my actions is as follows:

• make a punch ("blank"),
• choose a suitable transparent film,
• prepare the punch and film for tightening,
• heat the film to a softened state and cover the punch with it,
• Allow the film to cool without removing it from the punch, then separate the formed film from the punch and clean it.

I then cut out the canopy made in this way, mark the places where the binding will be glued and glue the binding, do the final finishing and install the canopy on the model.

Punch making

First of all, I take out the materials from which I will make the punch:

• good hard cardboard about 1 mm thick for making a frame, PVA glue for gluing and priming and soft wire 0.5...1 mm thick for reinforcing the frame,
• gypsum (alabaster) for the initial filling of the frame,
• latex or acrylic water-based putty for “finishing” the plaster punch,
• spray acrylic for final finishing of the punch.

The most expensive product in this set is the spray acrylic; Below I write that it can be replaced with the same PVA or any available transparent varnish - acrylic is needed in order to obtain a smoothly ground hard surface of the punch, so any suitable replacement is possible. Next in price comes PVA - you can use a quality that is not as good as shown, but you should not buy it in office supplies - it is very bad there; It's better to buy a jar at a hardware store. Putty and plaster cost the price of a bottle of good beer.

I make the patterns for the punch frame using the available prototype drawings, also taking into account the installation location of the finished lamp on the model and the related parts (binding). As an example, this is what my patterns made for the P-51 (A.Halinski, Military Model 5/2005, 1:33) and Yak-3 (GremirModels, 1:32) look like:

The principle of the frame structure is simple: a central longitudinal former, forming a longitudinal contour; transverse formers along the edges of the canopy; intermediate transverse shapers along characteristic sections. Frame patterns take into account the thickness of the film (I usually use a film 0.1 mm thick) - that is, the contours are made with an indentation “inside” by the thickness of the film, so that in the future the resulting lantern has exactly the outer surface that is needed.

These are examples of patterns that I had to make myself. However, some cardboard models include frame patterns for such a punch - an example is the Fw.190D model from GPM:

Making the punch frame from these patterns is not difficult - although in this case I would add a couple of the aforementioned cross formers along the edges of the canopy.

I glue the frame cut out of cardboard and pass a piece of wire through it as reinforcement (it subsequently prevents the plaster from falling out). I grind the edges of the frame and paint them with a colored marker - this is necessary so that later, when grinding off the excess plaster, I can stop in time. Finally, the frame is completely primed (coated) with PVA - to give it some water resistance.

When the frame is ready, I spread the plaster and fill the frame - with some excess:

You should not feel sorry for the plaster - it sets quickly, so it is better to immediately spread more and so that the entire frame is filled. There is no need to remove the excess - all the excess can be sharpened later. The frame filled with plaster is left in a warm place until it dries completely - visually this will be noticeable by how the initially wet and dark plaster lightens and takes on a “dry” appearance. Typically, at room temperature, a medium-sized punch dries out in a few hours.

I grind the dried workpiece with a rather coarse file until the ends of the frame appear. Then I sharpen it with a smaller file:

When the workpiece has accepted the required form, I cover it with a thin layer of putty, dry it again and sand it with medium-grit sandpaper until the final shape is obtained. Then I cover the workpiece with several layers of aerosol acrylic and sand it with the finest sandpaper (“zero”). The punch is ready:

Instead of aerosol acrylic, you can use any other transparent varnish, and you can cover the workpiece with a brush. You can also coat the workpiece with PVA glue instead of varnish. In all cases, several layers should be done with intermediate and final sanding. This is important: the unevenness left behind will definitely “imprint” unsightly on the finished lantern in the most visible place.

Selecting Transparency Film

To make the lantern, I use polyester film, which is used to make many things these days - plastic bottles, various types of packaging, and so on. Other types of transparent film (polyethylene, lavsan) are not suitable for this purpose. The film selected for the manufacture of the lantern must have the following properties:

• be absolutely transparent, free from unevenness and scratches,
• as the temperature rises, transition as gradually as possible from a hard to a soft state without melting;
• have a thickness of approximately 0.1 mm.

The first requirement is obvious; the second requirement is important because I heat the film over a gas burner, where the softening of the film can only be controlled visually. If the film quickly goes from a softened state to a molten state, it is difficult to work with.

The first and most accessible is films from some packaging. Such films always satisfy the second condition - as the temperature rises, they soften gradually and there is no danger of “overheating” the film until it melts (this is due to the fact that packaging films do not contain additives that increase their strength or thermal stability).

The first condition is worse: finding packaging that is clean and not scratched is quite difficult. However, I use film from the packaging of Korkunov candies - boxes with these candies, the lids of which have “windows” with film glued into them, are additionally packaged in cellophane, so the film from these boxes is protected from dirt and scratches and is usually perfectly clean and transparent :

This film also has just the right thickness - just over 0.1 mm.

Apparently there are other things packaged this way that can provide good clear film. However, considering that my family buys candy more often than I build models, I am provided with excellent film for years to come.

If you find a suitable package that is not flat, you can “release” it by gently heating it over a gas burner:

The heated packaging will quickly take a flat or almost flat shape, because it was made in some factory from a flat sheet of polyester - just the vacuum molding method mentioned above. This remarkable property of polyester film - to take the shape into which it was cast (most often, as in this case, the shape of a flat sheet) - will be further noted in connection with the ability to “pull” a lantern several times from the same segment films).

However, you should evaluate the “released” film for cleanliness and the absence of scratches - during the “release” process they may become apparent.

Second option - films used for bookbinding:

These films are usually clean and quite flexible and seem to be suitable for use (although I have not had to use them). In addition, when searching on the Internet, I did not find any offers for such a film thinner than 0.2 mm - and this is a bit too much. I think films thinner than 0.2 mm are simply rare - for the simple reason that this is too small for a strong binding ("crust"). Although, perhaps, somewhere there is a thinner binding film.

Third option - films used for printing transparent materials:

Although these films are high quality and clean, they have two drawbacks.

First, they have a layer on them designed to hold ink or paint while printing. This layer makes such films not completely transparent; it must be removed. From transparent film intended for inkjet printing, this ink-receiving layer is washed off with warm water, but you have to remove the remnants of this layer with acetone - which is not very favorable for the film.

Secondly, these films are manufactured for use in projectors, and therefore contain additives that increase thermal stability. Because of this, such a film does not immediately soften when the temperature rises, but it easily passes from a softened state to a molten one - it is quite difficult to keep track of this. As it heats up, it happens that the film warms up, heats up, heats up... and then at the moment when it seems to be soft and begins to ripple, it suddenly melts in the very middle. It looks something like how a jammed and stopped film in an old movie projector is instantly melted in the middle by a beam of light.

After the first experiments, I do not use such films - although they have an ideal thickness of 0.1 mm.

Preparing the punch and tight-fitting film

Preparing the film involves cleaning it from debris and dust; It also makes sense to wash it with detergent (in other words, soap). You should also choose a piece of film so that you can grab the edges with both hands and have enough space between your hands (for the examples below - approximately 10 x 10 cm), that is, the ideal length is 20 x 10 cm or slightly less.

Preparing the punch consists of covering it with some substance that would prevent the heated film from interacting with the surface of the punch (in other words, so that the heated film does not stick to the punch during hot tightening and is easily separated from it after cooling). For this purpose I use paraffin - an ordinary candle. I take a candle and rub the punch with its end so that it is completely stained with paraffin. Then I rub the paraffin with my fingers so that a smooth waxy layer of paraffin comes out to the touch, and I lubricate and shake off the excess paraffin - you need to leave a minimal layer, no lumps. It is best to rub it with your fingers, since the temperature of the finger softens the paraffin and easily smears (and the excess is smeared). You can hold the punch over a gas burner with low gas - so that your hands are hot, but no more.

Paraffin acts as a lubricant between the punch and the film - it ensures that the cooling film does not stick to the surface of the punch. In addition, due to its low thermal conductivity, paraffin does not allow the heated film to cool quickly when applied to the punch - if it cools quickly, it will not have time to take the shape of the punch.

It also plays the role of another leveling layer, but this is not so important if the surface of the punch is already smooth and clean.

Warming up the film and wrapping it around the punch

To heat the film, I prepare old warm leather gloves, a gas stove divider and a wooden block. I put the divider on the burner of the gas stove and turn on medium gas, letting the divider warm up.

At this time, I place the punch on a vertical wooden block - so that I can completely wrap the punch with a soft film with my hands. Correct installation can be checked by holding the edges of a piece of polyethylene of the same size as the selected sheet of film with both hands and pulling it onto the punch. If there is still some headroom left at hand to stretch the hot film, everything is fine; if not, you should choose a higher bar.

I take the sheet of film by the edges with gloved hands and begin to heat it over the burner. The moment the film softens during the heating process will be clearly visible - the film will begin to stretch elastically in your hands, and its surface will begin to warp and ripple. To increase the temperature, I lower the sheet lower to the burner, to lower it, I lift it. At the moment of sufficient softening of the film, I quickly transfer the film to the punch standing on the block, put the hot film on the punch, lower the edges of the film from left to right below the punch and pull the edges down until the film completely lies on the surface of the punch - that is, I wrap the hot film around the punch film. As soon as this is achieved, I freeze and start blowing on the film so that it cools down faster. A minute or two is enough for this.

This technique may not work the first time. No problem - I remove the cooled film from the punch, "release" the film over the gas back to the flat state (see above, which shows how this is done to "release" a non-flat package), and do the tightening again. This can be done as many times as necessary - until you get a perfectly covered punch, and you can use the same piece of film several times - until it is worn with paraffin and distorted to an unacceptable state. In this case, you should monitor the sufficiency of paraffin lubricant on the punch - its surface should be waxy to the touch. If necessary, paraffin can be added.

Cooling the film, removing it from the punch and cleaning

The film should be kept on the punch for one or two minutes so that it cools completely. Then I remove the cooled glass from the punch (usually not much force is required if it is well lubricated). After this, I wipe the glass with a soft rag (without scratching!) or cotton wool and wash it with detergent (soap) to remove traces of paraffin and other dirt that may appear.

The lantern is ready - now you can cut it out, glue the necessary parts, bring it to perfection and glue it in place.

Addition: the “hot hug” method from Andrew Inwald

A freely available Spitfire Mk.Va model kit by Andrew Inwald recently appeared on the KARTONBAU.DE and PAPERMODELERS.COM forums:

An absolutely wonderful part of the kit is the original way of drawing a lantern from film, and the kit itself contains all (or almost all - with the exception of putty) the parts needed for this (more precisely, the patterns for these parts).

The author offers patterns for the punch in the set - not only the frame, but also the casing of the punch:

According to this idea, gypsum is not needed at all, and at the same time, due to the frame corresponding to the geometry of the model, the resulting punch will have almost exactly the shape that is needed. The process of making the punch and then the lantern is illustrated by the following pages of instructions (I have reduced them and drawn the explanations in Russian):

Agree, everything is simple and logical. It is enough to lightly putty and sand the glued punch - and you need to sand it until the casing appears (this is important, because the joints of the punch casing determine the desired shape of the glass and an extra layer of putty will distort it). Next, from the punch (on the sheets I called it “assembly”) a simple but original device is made, which allows, firstly, not to burn your hands when heating and tightening, and secondly, to fix the cooled glass on the punch - it’s not only needed in order to give shape to the glass, but also in order to glue binding strips along its edges.

True, I must say that my first (and only) attempt to use this method was unsuccessful - pulling the film up is not very convenient, and gloves will be required anyway. Nevertheless, the method deserves attention.

In contact with

About dummies, matrices and lanterns
or Street of Plaster Lanterns

This article was originally dedicated to my most successful project - Kamikace Compact. By that time, I had already mastered making a lantern (on the Phoenix Bird project), but alas, I could not capture the process in photographs (everything was spontaneous, by trial and error), therefore, when making a dummy and a lantern, respectively, for Kamik, I captured the process in detail.

I make lanterns exclusively from PET bottles. Beer houses or shops that sell kvass. At least 2-3 liters and preferably brown. In extreme cases, you can do transparent ones, but then you will have to paint the inside with car paint from a can (a little bit to fog up in the light) because a completely transparent canopy on an airplane is pornography and it is not visible in the sky at all.

Styrofoam dummy

The lantern, according to the technology of gypsum products, begins with a foam block.

It is not ball or similar granular that is used, but red Penoplex or blue foam, used in electric aircraft. Penoplex is preferably the densest one available. Using 30mm plates we create a prototype of a dummy. The height is 70mm according to the drawings, so we glue 2 pieces together and glue the bag on top of the 10mm thick stubs. You can glue it on thick Henkel PVA or on Titan. On Titan the bag dries for three hours, on PVA overnight.

I advise you to have a cutting string for foam plastic - it helps a lot! However, you can use a knife to cut a 10mm (preferably with a margin) plate.

The tools used to make the primary block are a construction blade knife, coarse sandpaper, thinner sandpaper, and a very useful thing - both types of sandpaper glued to 2 sides of the plywood. It turns out to be a very convenient file. I mainly use it in sanding the blockhead.

I immediately advise you to make the blank blank longer than the cockpit plateau. 10-20 mm longer. This is necessary in order to then properly trim the edges of the stretched bottle and cut off possible folds (I’ll talk about this below).

First, we cut off the scraps from the blockhead, bringing its future appearance closer to the required shape. I’ll say right away that I make lanterns by eye. I don’t do anything exactly along the side profile. It is best to have a drawing in front of your eyes and approximately reproduce its shape. This will make it easier and there will be fewer mistakes and mistakes.

We stupidly cut off the layers of foam and get this blank:

The main part of the work is done with a plywood “file” and coarse sandpaper. Movements are circular and along the lantern. We try not to lift the foam. When more or less a shape is formed, we finish it with the other side of the “file” with finer sandpaper.

If you can’t get to it with a “file,” then take a piece of sandpaper (“flexible”) in your hands and, pressing it with your finger, carefully process the desired area. I had one like this at the transition of the forehead of the canopy into the edging repeating the shape of the cabin lid.

We constantly try on the bobblehead to the fuse to achieve the closest possible shape to the front part and especially to the gargrot.

At the end of all sandpaper work, we go over the entire surface with “thin flexible” sandpaper in order to smooth the surface as much as possible. As a result, we get something like this:

I always make these add-ons from scraps:

I glue the add-ons using droplets of slow cyacrine with an activator.

Preparing for casting

Well, here comes the most difficult part of the lantern making operation and at the same time the dirtiest.

At the hardware store I bought a painting bucket with a handle and a basin for something childish.

A 6 or 8 liter bucket (I don’t remember) will serve as a container for the matrix. The bucket is rectangular with a slight taper. A very good purchase for 95 rubles!

This is what the foundry looks like when it is 100% ready:

We glue the blockhead using Titan glue to a piece of cardboard that is the same size as the flat part of the bottom of the bucket. First, we put a 50-liter garbage bag in a bucket and put a block of cardboard in it (you can see it in the photo). The cardboard straightens the circumferential bottom space around the blockhead and prevents it from floating in the solution (this has happened).

We dilute alabaster in a basin. Important note!!! You need to understand that you can’t fill the matrix all at once; as a rule, you won’t calculate the volume of the solution and it will probably turn out thick. Therefore, as a rule, I fill it in 2-3 batches.

In this case, the solution needs to be liquid. The consistency is approximately the same as liquid sour cream or yogurt:

Casting technology

First, we pour water into a basin and pour alabaster into it (I use a glass made from a bottle), constantly stirring with a stick. Cooks roughly imagine the process. When you get the desired consistency (not water or thickness, but liquid sour cream), without waiting for anything, we begin to pour it into the bucket. First we pour over the block itself, and then we form the walls of the matrix. It is very important. In the first step we make some kind of shell around the blockhead, and in the second we modify the walls to a large thickness (which is determined by the size of the bucket and the blockhead itself). As a rule, during the breeding of the second pass, the first one has already solidified. Remember - alabaster hardens very quickly!

The height of the fill cap above the crown of the blockhead is at least 2 cm. This will be the thickness of the bottom of the matrix.

This is what the fill looks like immediately after the second pass:

Let it dry for about an hour, pull the matrix out of the bucket by the bag and remove the bag and cardboard. Our fool is exposed:

Much later, the idea came up - when pouring the matrix, put certain elements - stress concentrators - into the space between the block and the walls of the bucket. Let's say the strips of cardboard are vertical, placing them flat and diagonal to the center. Then it will be easier to break them, because they violate the integrity of the matrix mass.

As a rule, it is not possible to pull out the blockhead intact, so it must be etched out. There is no need to completely etch out the foam - you just need to help it come out on its own. We take acetone and pour it along the edges of the blockhead to etch its surface. Using a screwdriver or something like that, we try to pull out the blockhead. As a rule, it rests somewhere there, so we add acetone around the edges and touch up the necessary places. In the end, he crawls out with a smack, leaving a puddle of melted water. We carefully pull out this kaka; if something remains on the walls of the matrix, under no circumstances do we pick it! Let it dry a little. The acetone evaporates and the fused foam hardens. Then carefully remove it in the form of a crust.

Unfortunately, I didn’t take a photo of the stage of filling the blockhead, so I’ll describe it in words. The separating layer can be used in different ways. For the Phoenix Bird lantern I used the same trash bag, but then there will be inevitable wrinkles. Therefore, we make a mixture of soap and use a brush to lubricate the matrix inside. After drying, a film is obtained. We put 2 layers of porridge, since the first one will absorb the plaster.

This time I used a different separator - vegetable oil. Overall not bad either, but much worse than soap.

The solution for the blockhead needs to be made a little thinner. This is extremely important! If you leave the solution in a basin, then the quality of the block will not be up to par and it will need to be puttied. Which is exactly what I had this time. :-(

After pouring the solution, wait for three hours and very carefully break the matrix. Using a chisel and hammer, we first try to chop off the end walls and then very carefully make a shallow groove at the bottom of the matrix (where the crown of the blockhead is located). Thus, the matrix will fall apart along this stress line. Next, by gently hitting the walls of the matrix with a hammer and chisel, we try to split the matrix in two (preferably by chopping off pieces from the walls). As a result, we get a seed:

Due to laxity, this blockhead had to be puttied with a very liquid alabaster solution and then actively sanded. Ideally, you get a relatively smooth block, which then needs minimal sanding.

Wrapping process

I also didn’t film the wrapping process (I had no free hands), so I’ll also describe it in words. We cut the pre-selected bottle around the bottom at its base. The bottle should preferably be cylindrical, without any narrowing in the middle or embossed patterns. In general, the bottle should be as smooth as possible. I found a cool bottle of kvass (back in the summer, when there was a lot of this stuff).

We put the blockhead into the bottle so that the neck of the bottle hits the front end of the blockhead and slightly below (the blockhead in the bottle will be slightly skewed). We insert pieces of wood into the space between the wall of the bottle and the bottom of the block to reduce the volume of the tightening (the bottle does not tighten indefinitely!).

Using a construction hairdryer, we first “close” the bottle, that is, we heat the “skirt” of the resulting structure so that the edges of the bottle are wrapped around the back of the block (this is so that the block does not squeeze out of the bottle when tightening the main part of the surface). And we try to warm the blockhead first from above, and then from below. This is to prevent wrinkles from forming (for me it turned out at the very top).

Next, we heat the main part, pulling the entire space of the bottle onto the block. The temperature of the hair dryer is not at maximum (my hair dryer heats with two temperatures - 300 and 600 ° C), but at medium (I heated at 300). The bottle may begin to melt if heated to the maximum.

In general, after smoothing the bottle as much as possible on the block, we cut off the ends of the bottle, cut off the turn at the back end and the neck at the front, and also cut the bottle from the bottom. We remove the lantern from the blockhead and here is the intermediate result!

Final photos of the result:

Alexander Niskorodnov (NailMan)

Quite often modelers are faced with a very unpleasant moment. Need to make a new onecabin glazing (flashlight).

Since the one in the set is either lost, broken or cracked, or has the wrong shape or Bad quality. Manufacturinglantern, and indeed transparent elements of the model, is a rather important moment. Since transparent parts cannot be puttied or built up if they are not manufactured accurately. The part must be done immediately and as accurately as possible. There are several ways to make lanterns. I want to focus on the classic, time-tested more than once. Pullcabin glazing made of plexiglass using a punch and a matrix. First we make a matrix, exactly along the contour of the cabin. You can make a small margin of 0.1-0.2 mm for subsequent adjustment, cleaning and polishing. For this I use pieces of getinax, fiberglass or something similar.

Afterwards, from a type of wood, such as beech, so that there are no fibers and it is quite hard, we make a punch. Moreover, all punch dimensions must be reduced by thickness cabin glazing. But it’s better to increase the height a little so that the lower edge of the lantern is above the plane of the matrix when the punch is inserted into it. It is also better to mark on the punch, for example with a pencil, the lower edge of the lantern plus a small margin for cutting.

For large scales, 1mm thick plexiglass may be suitable, but for something like 1:72, you need to look for something much thinner or reduce the thickness yourself.

By the way, thickness is one of the reasons why some companies, especially when producing models using LND technology, for the manufacture cabin glazing films are used. Nowadays, from a huge number of packages, you can select a blank of the required thickness. Personally, for a number of reasons, I don’t like these films, and I use plexiglass to make lanterns. But let's return to our manufacturing process. To reduce the thickness, I grind down one of the sides of the workpiece to the required thickness on a piece of sandpaper. Usually new plexiglass is protected with film on both sides. Therefore, we remove it on one side and leave the other side alone for now, so as not to scratch it during the grinding process.

After obtaining the required thickness of 0.5-0.6 mm, remove the film. If necessary, if you want to make the lantern open, it can be made thinner. The side on which the film was placed will be the inner side, as it is smooth and without scratches. Now, near the heat source, where we will heat the workpiece, for ease of work, you can make something like this kind of slipway.

Then we move on to the pulling process itself. cabin glazing. To do this, hold the plexiglass blank with tweezers or something similar and heat it until it begins to bend easily under its own weight. It is better to heat over an electric stove or over a gas stove so that the plexiglass does not fall into the flame, but is heated above it. After heating, you need to very quickly place the workpiece with the polished side on the matrix and press on the smooth side with a punch.

You may not succeed the first time. Therefore, another advantage of plexiglass is that it can be heated again and it will take its original shape. Then you can try again. Of course, this cannot be done indefinitely. After obtaining the desired result, hold the punch for several seconds until the plexiglass cools completely. Then we remove the workpiece from the matrix and carefully begin to cut out the lantern.

If you have previously marked the punch, then along the marking lines, using a file, for example from a blade or a special one, we cut out the desired part.

Then we adjust the lantern in place. Since the outer side was not processed after sanding, now you can slightly adjust the lantern to its shape. If necessary, sharpen the edges, because during the drawing process, sharp edges collapse. Then we clean the lantern with waterproof sandpaper of different grits. Afterwards we polish it with GOI paste. I’ll say right away that this process not easy, but after training you can get excellent quality parts.

This article shows the manufacturing process cabin glazing made of plexiglass for the LaGG-3 aircraft manufactured by Roden on a scale of 1:72. This is what the lantern ended up looking like. And this is how it looks on the model.

The vast majority of thin-walled parts for homemade aircraft models are made by molding from fiberglass, or by drawing from sheet thermoplastic plastics. Recently, the range of materials available for working on hoods, wheel fairings and similar parts has changed and expanded significantly. Simultaneously with the advent of polystyrene and ABC plastic, many of the previously popular technologies began to fade into the background. Thus, the range of use of composite materials was limited only to highly loaded parts (fuselages of cross-country gliders and large model aircraft, helicopter bodies). In mass-produced kits, all molded sheet “small things” became plastic.

Of the modern common thermoplastics, the most durable is ABC plastic, which is now easy to buy in some model stores. It has one important advantage - it is not soluble in acetone. But buying this plastic even in Moscow is not an easy task. It is easier to obtain polystyrene sheets 1-1.5 mm thick. It, although not as strong as ABC plastic, in most cases satisfies all the requirements of modellers.

Let us immediately note that commercially available polystyrene sheets have much higher viscosity and reduced fragility compared to conventional household polystyrenes, and also that they are excellently glued with cyacrines.

White polystyrene is usually used. For copies it is better to look for a silver one. Painted plastic parts of this color take on a very realistic appearance as the coating wears. For the manufacture of transparent parts, plexiglass with a thickness of 1-1.5 mm is still best suited. But here we can also think about transparent polystyrene, although its light transmittance is somewhat worse.

In factories and more or less equipped workshops, the vacuum method is most often used for drawing plastics. In modern times, all vacuum pumps that could be privatized have already been privatized, and what can be bought is expensive. Therefore, let’s consider the most “home” technology.

As a tool, first of all, you need a blank (punch). It is made from linden, balsa or dense foam. The balsa blank must be primed to harden the surface. A suitable primer composition can be prepared by adding talc (or baby powder, which you buy at the pharmacy) to the nitro lacquer. By increasing the talc content, a putty is obtained, with which it is easy to correct surface defects. If dense foam plastic is used, it is necessary to cover the blank with parquet varnish or epoxy resin diluted with acetone.

The working surfaces of the blank should be rubbed with stearin (candle) or polish, wait about an hour and lightly rub with a woolen cloth. In this case, the stamped plastic will slide more easily along the surface of the punch and at the same time the local thinning of the material will decrease.

There are several extraction methods, each of which requires its own additional equipment.

First way. Used for shallow drawing of small parts. (Hereinafter, it is assumed that the products have only positive curvature over the entire surface). The thermoplastic sheet is crimped from two opposite edges with strips of plywood 4-10 mm thick using screws. Using two pliers, the sheet is held over an electric stove, heated to a plastic state, and then the entire blank or part of it is manually covered with it. Instead of pliers, you can use clamps, or make special handles in plywood frames, which will allow you to apply more force.

It is advisable that during operation the air temperature in the room should not be lower than 20°C; at a lower temperature, the plastic quickly cools down and loses its plasticity. If, after contact with the blank, the material manages to harden even before the end of the drawing process, the punch can be heated in the oven to 50-60°C (this does not apply to foam plastic blanks).

The disadvantages of the method include the fact that when heated, the sheet narrows in the middle, and its edges turn up. This forces you to cut out the workpiece with large allowances.

Second way. A frame is made from plywood 4-10 mm thick so that a punch passes through it with a gap on the side equal to 1.2-1.5 times the thickness of the plastic. The working edges of the frame must be rounded and carefully sanded. The bars are nailed to the frame, which will serve as its base. The width of the plastic workpiece is taken to be three times the size of the hole in the matrix. The plastic is heated until completely softened (at the same time it shrinks greatly), placed on the frame, and the punch is pressed into the hole of the matrix with hands or a clamp. Without releasing the punch, the plastic is allowed to cool, after which the finished part is removed from the blank. General dignity this method- minimal thinning of the material.

Sometimes folds form on the product. This depends on the shape of the part, but can also be caused by an excessive gap between the die and the punch, or insufficient heating of the plastic.

Third way. In this case, two identical matrix frames are made. The stamped material is clamped between them, as in the first method. If the matrices with plastic are heated in an oven, then the frames can be absolutely identical. The temperature should be selected experimentally, starting from 70°C.

Sometimes, especially with small part sizes, it is more convenient to heat the plastic over an electric stove. This will allow you to observe changes in the state of the material. In this case, one of the frames (calibrating) should have a gap of 1.2-1.5 times the thickness of the material along the contour of the blank, and the second - about 7 mm (the matrix should be held above the tile with the frame facing down with a large gap). When the plastic begins to sag, it is ready for drawing. Strong evaporation of material from the surface is a sign of overheating. When installing the punch on the table, be sure to use stops to prevent excessive drawing depth (otherwise the part may turn out to be too thin). To reduce the thinning of the plastic, the tightening of the bolts holding the frames together can be reduced so that the material can be pushed out into the exhaust area.

Fourth way. It is used when the product has protruding elements or recesses (for example, ribbing on the hood). Again, it is necessary to make a matrix. Its internal dimensions should be greater than the dimensions of the blank-punch by the thickness of the material. Achieving this by processing using templates is not easy, so you can resort to a little trick. The blank should be covered with a separating layer (floor mastic, polish, stearin), and then rubbed until shiny. Using a brush or sprayer, apply several layers of diluted epoxy glue. The number of layers must be determined in advance on a prototype of any material so that their total thickness is equal to the thickness of the plastic after drawing (about half of its original value). After the glue has cured, the surface is covered with another separating layer, and covered first with thin and then with thick fiberglass, forming a hard crust. Then the resulting matrix is ​​removed and the “equidistant” epoxy resin coating is separated from the blank.