Aircraft model manufacturing technology. Windshields for airplanes and helicopters to order How to make a lantern for an airplane

November 1, 2019 The next 17th virtual bench model competition DiSHow-2019 has started.

Preliminary schedule of competitive and non-competitive publications:
Monday - non-competitive works;
Tuesday-Friday - competitive works;
Saturday-Sunday - free days.

Depending on the number of works submitted to the competition, the schedule may change. We kindly ask authors to carefully monitor the publication of their works and check the nomination of published works. If you have any questions, please contact the administration immediately.

Good luck to all!

Two simple ways to make bindings on model airplane canopies.

Sergey Mashnov aka Sam Blake

viewing photos in a separate window
viewing photos in lightbox mode

One of the types of work when assembling aircraft models is the manufacture of glazing on the cockpit canopy.

There are several technological methods for this. I would like to introduce you to two of them, which in my opinion are the simplest. To do this, in the first case we will make masks on glass of a simple shape, in the second - on curved surfaces.

For the first (1) we need painter's, car or, best of all, special modeling tape and a very sharp knife. For the second (2) - BF-2 glue. It is advisable to take it in pharmacies and, most importantly, that it contains ethyl alcohol. It is advisable to check it before using it on an unnecessary transparent sprue. Now the Chinese can even forge the mausoleum on Red Square overnight, not to mention the glue recipe.
The glue itself is quite fluid, but I dilute it even more with alcohol for better spreading. However, in this case, you have to turn the lantern over so that the glue spreads evenly over the surface without accumulating at the bottom.

1. Cut off the adhesive tape and stick it onto the glazing, if possible, so that its smooth edges coincide with the binding of the lantern. It is also advisable to avoid applying another layer of adhesive tape. Using a toothpick, we draw lines along the binding, achieving maximum adherence of the tape. Then, with a pencil, we draw lines along the edges of the binding so that it is better visible where to cut through the masks.
2. Using a thin stick (I use pieces of stiff wire or a piece of an umbrella knitting needle for this), apply glue evenly over the entire surface of the glazing. We repeat the procedure after two hours, applying a second layer of glue.
Final drying requires at least three hours

1-2. Using a sharp knife, carefully draw along the drawn lines, trying not to catch the covered areas.

1-2.Remove the cut strips of tape and glue, exposing those places that should be painted over.

Acrylic products

Acrylic or organic glass has been used in aviation for almost a hundred years. The invention of this material occurred during the period between the two world wars. The unique characteristics of acrylic have become the reason for its increased demand in the field of military and civil aviation. The new material for the cockpit windshield had optical transparency, shatterproofness, and water resistance. In the post-war years, flight speeds and altitudes grew indomitably, and the industry developed at a rapid pace.

At the same time, acrylic glass manufacturing technologies were developing, and the properties of this material were striving for perfection. Increased demand for plexiglass in aviation is also observed in our time - acrylic is the only material that can withstand the most difficult operating conditions in the air. Today, only acrylic aviation plexiglass is used for glazing cockpits of combat and civil aircraft and helicopters.

Windshields for airplanes and helicopters: glazing of combat aircraft

Acrylic acts as a powerful force link along with the metal elements of the body structure. The safety of the crew and the success of combat operations depend on the reliability of the windshield of an airplane or helicopter, so we take full responsibility for the quality of our products.

- Highest impact strength. Strength is determined based on the most difficult operating conditions during combat operations. Acrylic glass for aviation withstands not only bird strikes, but also vibration loads associated with extreme maneuvering of the machine. The use of acrylic with bullet-resistant properties protects the combat vehicle from fragments in the most critical moments of the battle.

Civil aviation: custom windshields for airplanes and helicopters

Acrylic glazing is an excellent solution for making custom windshields for airplanes and helicopters. Acrylic allows you to create elite-class models, unique in their design. Regardless of who will use the aircraft - private individuals or official representatives of states - the requirements for such structures are very high. Airplanes and helicopters of increased comfort for VIPs must ensure absolute safety of transportation and at the same time have a high-class appearance. Acrylic allows you to solve these problems easily and without extra costs.

Excellent aesthetic characteristics. Shiny and perfectly smooth acrylic glass has a high light transmittance, the transparency of the material is maintained in all weather conditions throughout its entire service life.

Any design. The technological capabilities of acrylic make it possible to create aviation products from acrylic of any configuration without minimal damage to strength and reliability.

Self-cleaning surface. The possibilities of acrylic in ensuring the ideal condition of glazing are quite wide. Thanks to a special dirt-repellent coating, the surface of the glass always remains clean and shiny, and therefore does not require intensive care.

Noise and UV protection. Special technologies make it possible to produce custom-made windshields for airplanes and helicopters with protection from the negative effects of solar radiation and noise. Staying in the cabin becomes as comfortable as possible, while natural light remains at the maximum level.

Frost and heat resistance. Acrylic glazing of aircraft is designed for operation in a wide range of temperatures - from the scorching southern heat to the burning northern frosts.

The AkrylChik company has a powerful technological potential that allows it to work with complex aircraft glazing in accordance with the stringent requirements of state and international standards.

Polishing aircraft and helicopter glazing

In order for aircraft glazing to serve for a long time and without failure, it is necessary to periodically perform polishing work. Polishing allows you to remove the smallest abrasions and scratches that could appear due to contact with birds, insects, dirt, and precipitation. Smooth polished surfaces do not retain the smallest particles of dirt, moisture, or ice. A self-cleaning effect occurs on the surface. Timely contacting our specialists for service is a guarantee of long-term operation of aircraft glazing. Regular polishing improves not only the performance, but also the aesthetic characteristics of the machine. High-quality polished glass provides an excellent overview and clearly conveys colors and shapes. Glossy surfaces emphasize the presentable appearance of the aircraft and serve as an attribute of the high status of the aircraft owner. By entrusting the glass polishing to us, you will make a profitable investment in the durability and reliability of the aircraft. Polishing work is carried out by high-class specialists. A team of craftsmen can go to a site in any city in Russia and perform a full range of turnkey polishing work on aircraft or helicopter glazing.

Aviation plexiglass

Technical characteristics of aviation plexiglass according to GOST 10667-90:

Aviation plexiglass GOST 10667-90. A wide range of organic glasses has been developed for glazing air transport. Let's consider one of the most popular options - aviation plexiglass (acrylic), which is produced in accordance with GOST 10667-90. The thickness of such glass varies from 1 to 50 mm. Dimensions of sheet blanks: 1170x1340 mm and 1500x1700 mm. Other sheet dimensions can be ordered from manufacturers upon individual request. Aviation plexiglass brands: SO-95A, SO-120A. The abbreviation CO means “organic glass”, the subsequent number is the softening temperature at which the thermal molding of plexiglass is carried out, the letter “A” indicates that the material is intended for use in aviation, namely for glazing airplanes and helicopters.

Aviation plexiglass GOST 10667-90 has excellent performance characteristics. Fire safety indicators comply with GOST 12.1.044. The material does not emit toxic substances at operating temperatures.

Technical characteristics of aviation plexiglass PLEXIGLAS GS:

Aviation plexiglass PLEXIGLAS GS. Evonik, with whom we have been cooperating for many years, also offers a line of organic glasses for aviation applications. In particular, plexiglass of the brands PLEXIGLAS GS 249, PLEXIGLAS GS 245, PLEXIGLAS GS 241 is used for glazing aircraft. These materials have excellent optical properties, mechanical strength and fracture resistance, low weight and surface rigidity. Additional intermolecular bonds make plexiglass resistant to environments that cause cracking.

The material is produced in both colorless and tinted transparent versions. Thickness - from 2 to 85 mm. Plexiglas for aviation PLEXIGLAS GS is certified in accordance with aircraft industry standards. The main area of application of aviation plexiglass PLEXIGLAS GS:

- glazing of ultralight aircraft;
- glider lights;
- glazing of helicopters;
- airplane lights;
- glazing of commercial aircraft cabins;
- lights and windshields of fighter aircraft;
- multi-layer windshields of aircraft.

Technology for manufacturing aircraft models from various materials and instructions for their processing.

Everyone enjoys prefabricated airplane models, but they are not always affordable yet. This circumstance may seem annoying to some, but this is only at first glance. A rather interesting and original tabletop model of an airplane can be made even from paper, and if you use wood or plastic, you can learn to make models no worse than “branded” ones, because no one requires them to fly.

This approach greatly simplifies the matter for those who decide to devote their leisure time to the design and manufacture of desktop replica models. The main thing is to ensure that the model looks authentic on the outside, and what it is made of inside does not matter. Therefore, when working on a tabletop “air show”, a variety of materials will find their use: cardboard and paper, wood, plywood and polystyrene waste, various polystyrene food packaging.

First, try making a bench model of the famous Soviet Pe-2 dive bomber of the Great Patriotic War on a scale of 1:72. Figure 6 shows its main projections, templates for manufacturing the body and wing, and Figure 7 shows the manufacturing technology. In order to make a model, it is best to use soft wood: aspen, linden, poplar or small-grained spruce.

The fuselage is made of a solid wooden block, but if you want to make it hollow, then make the blank from two bars, which are glued with thick paper (Fig. 7, a). This is necessary so that the finished fuselage can be separated and hollowed out from the inside.

Start your work by transferring the projections of the model fuselage onto tracing paper. Then paste this tracing paper onto the workpiece and process it along the contour. In the same way, transfer the top view to the workpiece (Fig. 7, b). During final processing, check the correctness of the fuselage sections A-A, B-B, B-C (see Fig. 6) using templates (Fig. 7, c).

The wing is made of a solid board. If there are no boards of suitable sizes, then glue several bars together. Process the resulting workpiece in the same way as the fuselage. When profiling the wing, use the templates of sections G - D and D - D. To give the wings a transverse V, saw the joint of the center section and consoles, and then glue them at the required angle. Make the engine nacelles and tail surfaces in the same way. The cockpit canopy can also be made from wood. In this case, paint all glazed surfaces with black paint.

Let's take a closer look at making a transparent plexiglass lantern. It is transparent and almost does not change color when exposed to sunlight. As the temperature increases, plexiglass becomes plastic, which allows you to pull out parts of various shapes from it. The most favorable temperature for processing is 110-135°C. At higher temperatures, bubbles appear on the surface of the plexiglass, which leads to defective work.

The drawing method (Fig. 7, d) consists of drawing heated plexiglass in a wooden mold consisting of a blank punch 1 and a pass-through matrix window 2. The punch is cut from a piece of hard wood (beech) according to the drawing. Then it is coated with casein glue, dried and thoroughly cleaned with fine sandpaper so that the wood is not exposed. Casein glue can be replaced with epoxy resin or enamel, but in this case the glue is left only in microcracks, and the punch itself is completely cleaned to a shine.

Matrix 2 is cut out of 3...4 mm plywood so that the hole is 1.5 mm larger than the dimensions of the punch. The edges of the matrix must be carefully rounded and processed with sandpaper. Wooden blocks 3 are nailed to the matrix from below.

Plexiglas 1 mm thick should be approximately 3 times larger than the hole in the matrix. It is heated over a closed fire (electric stove) until softened. Then the workpiece is placed on the die and the punch is pushed into the die hole with a quick continuous movement. The force is removed after the plexiglass has cooled. The finished lantern is removed and excess materials are trimmed. In order to prevent wrinkles from forming on the lantern, it is necessary to make a clamping matrix 5 and, during drawing, press the workpiece against the main matrix. Sometimes imprints of unevenness of the punch or wood structure remain on the finished lantern. These irregularities are treated with fine sandpaper and then polished.

When assembling the model, special attention should be paid to the symmetry of the parts and their correct orientation. After the model is assembled, you need to carefully fill all the gaps between the parts. It is better to use epoxy putty, nitro putty

АШ -22 or АШ -30 or oil putty PF002. But you can prepare the putty yourself. To do this, the lumpy chalk must be wiped on a grid and diluted on enamel until the desired thickness is obtained. For a softer putty, you can add some nitro paint. Before painting, the entire model is covered with a layer of primer, then putty again and carefully treated with sandpaper.

This model is made from polystyrene in almost the same way. The necessary parts, say a wing, can be cut out of sheet polystyrene 2...3 mm thick, and then “finished” with needle files and sandpaper. The fuselage is glued together from a package of polystyrene plates. To cover the surface of the model, it is very good to use thin sheets of polystyrene from food packaging or glossy coated paper. Polystyrene finishing allows you to show the smallest details on the surface of the model, including even rivets. They are perfectly “stamped” (pierced with a dull needle) on workpieces from the inside. You can imitate the joints and seams of the skin, glue hatches and fuel fillers onto it, make blinds and radiator grilles, and covers for pilot lights. The small thickness of polystyrene makes it possible to effectively use it for fins of bombs and missiles.

Cutting sheets of sheathing can be done directly on the finished product, especially if you prepare cutters for polystyrene, shown in Figure 8. The largest of them (a) is very convenient to use a metal ruler to draw straight lines on the surface of polystyrene, along which it easily breaks into pieces.

It is advisable to make several such cutters, made from fragments of a hacksaw blade for metal (b, c, d) for each type of work separately. For example, to make a thin, shallow “joint”, the cutter needs to be sharpened at an angle of 30°, and for deeper and wider ones – at an angle of 55° and 80°. Particular attention should be paid to the precise penciling of the cutting lines that appear in the drawing. Round “joint” elements (for example, hatches) can be easily made using tubes of various diameters sharpened at the edges. When you lightly press the tube, a faint mark remains on the polystyrene; to obtain the required depth, you need to turn the tube 2-3 turns.

After all the cutting has been completed, the surface of the model is treated with fine-grained sandpaper, and individual defects are repaired using putty. Having completed all this work, you can begin painting the model, once again carefully reading our recommendations for performing this important operation.

One or two models made using this technology (drawings for this work are regularly published in such magazines as “Wings of the Motherland”, “Model Designer” and “Young Technician” along with an appendix) - and you will become a real model-copyist, and your “air show on the table” will begin to be replenished quite quickly with new aircraft models, chosen solely at your request.
At the same time, turning to various kinds of reference books, encyclopedias and special magazines will make you a real specialist in the field of aviation.

And a few words about organizing your work. In our opinion, it is rational, for example, to make several blanks of the same type at the same time, when the appropriate tool has been adjusted and manufactured, as they say, for this operation. This makes it very convenient to turn wheels, make propeller blades and stamp cabins. If there are several models, then it is more convenient to paint them: the work is simplified, the final finishing time is reduced, and paint is saved.

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 lantern 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 taken the desired shape, 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 a transparent film intended for inkjet printing, this ink-receiving layer is washed off with warm water, but the remnants of this layer have to be removed with acetone - which is not very beneficial 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 move 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 of 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

How to make a cockpit canopy at home and at minimal cost?
I thought that this topic had not been relevant for a long time, but if you take into account the number of questions received, I understand that I got excited. Therefore, I decided to devote a separate article to how I make lanterns on a model from a plastic bottle. What is pleasing about this process is that business is combined with pleasure. And the costs are really minimal and come down to the cost of the drink, the plastic bottle from which will be used as a material. I don’t know about anyone, but for some reason I like lanterns made from beer bottles the most. However, let's get down to business...

Actually, there’s not so much to do, you need to make a blank. To do this, we take a block, I used linden, it is more uniform and easier to process. First we process the side surfaces to obtain the desired shape of the bottom surface. Dimensions can be taken from the drawing, from the top view, or by directly measuring the fuselage. It should look like a trapezoid. Then, on a piece of whatman paper or cardboard, I copy the profile of the future booth from the drawing and make a pattern. I use it to mark the blank with an allowance along the length and bottom:

After this, naturally, the top of the blank is processed along the contour. There are many ways, first you can do this:

and then like this:

After 20-30 minutes you get something like this:

We apply markings to the ends of the workpiece:

I copied the contours directly from the fuselage onto the same Whatman paper and made patterns.
After this, I pre-processed the back of the blank:

Then he tore off the front:

Now all that remains is to refine our clumsy (in the literal sense of the word) work and give it a finished look. 20 minutes of sanding and we get a cool blank:

Now you will have to put your work aside for a while and rest a little, especially since this is simply necessary to continue working.
Having assessed visually (and maybe even instrumentally) the dimensions of our blank, we head to the store, where the largest possible range of drinks in large plastic packaging is presented. I don’t know why, but I prefer brown-tinted booths, so I was “forced” to look for a lantern blank in the beer section. The 2.5 liter bottle of Bolshaya Kruzhka beer was almost perfect in both form and content. Having used the contents of the workpiece for its intended purpose, carefully cut off the bottom and stuff the blank into it. To avoid having to shrink the plastic a lot, we somehow fix the blank inside the workpiece.