EP3094431A1

EP3094431A1 - Method for producing three-dimensional sculptures

Info

Publication number: EP3094431A1
Application number: EP14777584.5A
Authority: EP
Inventors: Elmar Westhoff
Original assignee: Otto Junker GmbH
Current assignee: Otto Junker GmbH
Priority date: 2014-01-17
Filing date: 2014-09-29
Publication date: 2016-11-23
Anticipated expiration: 2034-09-29
Also published as: WO2015106843A1; WO2015106843A9; DE202014011185U1; DE102014100513A1; EP3094431B1

Abstract

The invention relates to a method for producing three-dimensional sculptures according to an original object, in particular according to a living model. The individual machining steps are to be coordinated such that the complexity of the production is significantly decreased without having to reduce the quality of the final product. The method is characterized by the following steps: - scanning, i.e. scanning and/or photographing or filming all the dimensions of the object in order to generate a virtual three-dimensional image, - modeling, i.e. processing the individual scans and photos or films into a realistic virtual copy of the original object, - producing a model bust or characteristic parts of the sculpture in a 1:1 scale, - designing and producing the casting model or the casting models, - producing the mold or the molds using the casting models, - casting the mold(s), - aftertreating the cast part or the cast parts, and - optionally welding the individual molded parts in a formfitting and bonding manner. Alternatively, it is also possible to produce the mold or the molds immediately after the modeling step by means of a rapid prototyping process using the ascertained SD data and a corresponding computerized simulation process.

Description

Method for producing three-dimensional sculptures

The invention relates to a method for producing three-dimensional sculptures according to an original object, in particular to a living model. It has long been known to make models of living or deceased humans, but also of animals or other three-dimensional designs in order to obtain them permanently, in order to collect or pass through them

To enjoy remembrance. The choice of materials for the production of such models are virtually unlimited. Depending on the material, however, the production of corresponding sculptures is sometimes quite costly, especially if the models are correspondingly large, since sculptures made to such an original scale 1: 1 or, if necessary,

corresponding enlargements must be made from a variety of individual sub-forms. Individual necessary processing steps, such as scanning and the calculation of virtual images or 3 D objects from such scans have been known for a long time. The problem here, however, is that a variety of different steps is necessary, all of which require the most diverse know-how in various technical fields. It is the complete manufacturing process from the idea to the final finished sculpture therefore requires a variety of different expertise and a corresponding number of involved people and processing locations.

The invention has therefore set itself the task of demonstrating a manufacturing method for producing three-dimensional sculptures, which is a perfect

Coordination of the individual processing steps includes to achieve a manageable effort with an optimal result. Such Vorf ⁱ h "n cnii ™ .riccor moderation" take place under one roof ". This task is initially solved by the following steps:

Scanning, d. H. scanning and / or photographing or filming all

Dimensions of the object to create a virtual three-dimensional image,

Modeling, i. Processing or editing the individual scans and photos or films into a realistic virtual copy of the original object,

Making a model bust or characteristic parts of the sculpture in the

Scale 1: 1,

- design and manufacture of the casting model or casting models,

Making the mold (s) using the casting models, casting the mold (s),

After treatment of the casting or castings

if necessary, positive and cohesive welding of the individual molded parts.

Another teaching of the invention provides that after modeling a

miniature 3D model is made. This is - especially for larger ones

Sculptures - useful in order to exclude "unpleasant surprises" in the finished product if possible.Faulty and / or incomplete scans can be detected in this way in time, so the position and expression of the sculpture can be defined and optimized in advance.

An alternative solution to the problem is described in the following steps: Scanning, d. H. scanning and / or photographing or filming all

Dimensions of the object to create a virtual three-dimensional image, modeling, i. Processing or editing the individual scans and photos or films into a realistic virtual copy of the original object,

Making the mold or molds by means of rapid prototyping

Use of 3D data from modeling and computational

Simulation process, Casting the mold (s),

After-treatment of the casting or castings,

if necessary, positive and cohesive welding of the individual molded parts. In particular, the alternative method is characterized by an extreme time and cost savings, since all the steps from the first scan to the

Manufacture of the molds can run fully automated. Through the 'Rapid Prototyping', the data obtained during modeling can be used to directly produce a negative mold made of sand on appropriate devices, into which the casting can then take place. Of course, it is also possible with this method, after modeling first to produce a 3D model, especially in more complicated forms or sculptural judgments.

A further embodiment of the invention provides that the production of the model surface milling by free-form or by .Rapid Prototyping 'is done. The odell can preferably be made of plastic, for example by means of an SD printer. However, it is also a production of metal or wood possible. The model bust or characteristic parts or the miniaturized models are preferably provided with a special plastic / metal coating, in particular if the finished sculpture is to be made of stainless steel and / or mirror polished. In this way, a realistic impression of the finished sculpture can already be achieved.

According to a further embodiment of the invention, it is provided that for the design of the casting model mathematical Formfüllungs- and solidification simulations

be carried out to determine the optimum casting technique.

With the help of the casting model (s), the casting mold (s) are / are molded or directly from the 3D data of the modeling and the computational simulation by means of rapid prototyping, a process known per se, in which the molding base material is applied in layers with a suitable binder system , directly without model geprintet. Subsequently, the mold (s) are (are) sized. Preferably, the finished mold (s) are heated to a predetermined temperature for a defined period of time so that the optimum mold temperature and a minimum of residual moisture in the mold are set immediately prior to casting in the mold.

A further teaching of the invention provides that a quality assurance takes place after the casting aftertreatment. This can take place, for example, in a surface inspection by the dye penetration method, so that a corresponding

Post-processing of the defects can be done.

According to a further embodiment of the invention, the sculpture is made of stainless steel in order to achieve a high quality and a long life. As already mentioned, a special embodiment of the present invention provides that the finished sculpture is mirror-polished. In addition, the sculpture can then be coated with lacquer or powder coating so that the polish finish remains intact. The exact sequence of production is described in detail below:

Preference is given to the production of cast in stainless steel and mirror-polished sculptures for living (or a deceased) role model. The size of the finished sculpture is variable, depending on the actual size of the prototype, a scale of 1: 9 to 3: 1 is possible.

The first step is to create a virtual three-dimensional image of the (usually) living prototype (so-called "scanning") .The scanning can be done either by scanning and / or photographing or by filming used to create the 3D data. Photography / Scanner: For this, the living object becomes from all perspectives

photographed / scanned so that all dimensions of the object are captured. In addition, lighting effects must be exploited so that the surface contours become visible.

Film / Scanner: For this, the living object becomes from all perspectives

filmed / scanned so that all dimensions and surface contours of the object can be captured.

For example, scanning can be done simultaneously with multiple (typically 8 to 12 cameras) scan cameras. These cameras are evenly adjusted to the object to be scanned around the object so that all areas can be scanned optimally. At the same time, photos are also created with these cameras. Undercuts are additionally photographed with a high-resolution camera, as they can not be detected by the positioned scanners. Advantage of this system is that even moving objects, such as

For example, animals can be scanned and the 3D model can be processed directly in the computer. Modeling now processes and merges the processed scanner data with the additional photographs. The virtual lifelike, real image of the captured object can only be created from the combination of data (scanner, photography and film) and modeling. In the subsequent "modeling" the photos / scans and or

The film / scan of the living (or decaying) role model on the computer is processed, modeled and networked in such a way that a realistic virtual copy of the living (or decaying) role model emerges. Together with the customer, the position, posture and position of the future sculpture during computer modeling are defined and the characteristic features

worked out. The computer modeling and virtually realistic replication is done by iterative optimizations and comparison with the photo, scan and film material. Preferably, especially for larger models, after the final virtual computer modeling, a model is milled on a reduced scale or manufactured by "Rapid Prototyping". For this purpose, the computer data is converted into corresponding processing data. By free-form surface milling or by rapid prototyping preferably a plastic model of the virtual model is made. This model can be coated with a special metal coating so that the visual effect of the later sculpture can be simulated.

After the model has been manufactured and released, will be at the first

Alternative of the method according to the invention made a bust or a characteristic detail on a scale of 1: 1 and coated with a special metal / plastic coating to ensure that the essential details of the living (or deceased) prototype are accurately formed and the

Traits that are essential to the client, even in the later

Execution are clearly recognizable, and comply with the ideas of the client.

After adjusting the model and the bust with the photos and / or films as well as with the computer models, the final production release for the stainless steel casting takes place. Before the casting model production, mathematical form filling and filling are now

Solidification simulations performed to optimize the mold filling during casting and thus to avoid defects in the casting.

In casting model production, the following conditions must be taken into account: a. Plastic or wood model: Dimensional accuracy must be ensured when taking the model.

b. Model Division: The casting model must be divided so that the

Model divisions run along the natural contours (wrinkles, neckline, leg lug, etc.).

c. The casting model must be developed so that the casting mold is rising

can be poured.

Based on the results of the computational simulation, the

Cast iron models made. In the second alternative of the invention

Procedure, the 3D data of the modeling together with those of the

Computational simulation prepared so that records arise with which

Molds by rapid prototyping by layering printen of

Mold base and binder can be produced. If the molds are produced by means of casting models, a plurality of casting models and core boxes may be needed, depending on the complexity and size of the model / living being. Depending on your size, the sculpture must be cast in individual segments. The mold is made in such a way that the cast half forms a shell and does not warp when it solidifies because the sculpture is hollow after completion.

The molds are made manually or using a 3D printer (rapid prototyping method). As molding material, various natural as well as synthetic sands are used (quartz sand, chrome ore sand, zircon sand, etc.). As a binder system is a special known per se

Cold resin method applied, which is characterized in particular in steel and stainless steel casting by high surface qualities. The binder system envelops the mold base material and gives the necessary after curing of the mold

Dimensional stability. The surface quality of the casting is significantly influenced by the molding material in combination with the subsequently applied size. When the molds are finished, fan heaters with a prescribed temperature are connected to the molds for a defined period of time. These

Fan heaters extract moisture from the molds. In this way, the

Gas pore formation (so-called 'pinholes') avoided in the later casting. A defined time before casting the heaters are removed from the molds and the casting takes place immediately.

All molds are designed so that the molds are poured downwards and thus impurities, which are on the surfaces of the melt or in the melt, can flow into the feeders or into overflows. All process steps are designed for maximum purity and process reliability with regard to maximum casting quality. The material used for the melt and alloy are special stainless steel alloys characterized by the following "decisive"

Characterize properties so that the polishing of the sculpture surface creates a uniform, flawless mirror surface:

The material must not form precipitates during solidification

The material must have a low segregation behavior.

The material must be characterized by a very low gas absorption

The material must be mirror-polished and must not be polished after polishing

Shades / discontinuities due to structural differences or visible

Grain boundaries, precipitations, Seigerungsphänome or the like.

The melt guide is the quality-critical process step. So that no impurities and gases adversely affect the quality during the solidification of the casting, the melt must be subjected to a vacuum treatment. In addition to the carbon, the vacuum treatment reduces the gases such as nitrogen, hydrogen and oxygen below the Boudouard equilibrium required standard values. These otherwise melt-dissolved gases would precipitate upon solidification and form intolerable pores, oxides or carbides on the surface. Following the melting process, the actual casting takes place. For this purpose, a pan, in which the melt is transported to the mold, flooded with a protective gas, so that even when tilting the melt from the furnace into the pan almost no gas absorption can take place. The pan is a stopper pan, allowing the melt to flow directly into the mold via a bottom outlet. The distance between the mold and the floor outlet is max. 10 cm to also minimize gas uptake of the pouring stream during casting.

The demolding of the castings takes place exactly after 24 hours, in this way reproducible and uniform structural properties of all cast halves are formed. This is further supported by the fact that the castings are shell halves with a uniform wall thickness. This is the only way to avoid metallurgical inhomogeneities. The wall thickness of the sculptures is calculated and adjusted on the basis of the sculpture size, the material properties and the necessary static sculptural properties.

For cast aftertreatment (cast brushing) after demolding the

Guss halves or castings carefully sanded. Blasting with blasting grain or the like is avoided because hardening of the surface by blasting results and the polishing ability decreases. Subsequently, the casting and

Removing the feeder system by sawing or cutting, so that a heat input into the component, which can lead to a structural change, is avoided. Carefully, the casting skin is removed by grinding with permanent temperature measurement. A previously defined component temperature must not be exceeded in order to avoid microstructural changes. After the post-treatment the quality assurance takes place. This begins with the surface inspection. Here, the dye penetration test is chosen as the test method. Defects that are invisible to the human eye become visible and must then be sanded out with fine special sanding heads. Subsequently, the defects with the lowest possible with an approved for the selected casting material electrode / welding wire

Heat input welded _» added and inspected.

Afterwards, the segments are measured and welded to each other accurately fitting and checked again by means of dye penetration test.

The mirror polishing must be performed expertly, this will be in a specializing in the mirror polishing operation all casting halves form and

cohesively welded. It is essential when welding that the welds are no longer visible after polishing. The microstructure of the welds must match that of the casting and together form a homogeneous, uniformly polishable surface. In this way, a finished sculpture can be formed from any number of individual pieces of sculpture. After complete assembly of the sculpture it is preferably mirror polished by a special grinding and polishing process. This process takes place in several steps: rough grinding, fine grinding, polishing and

Mirror polishing. It is essential that the removal of the surface at all points of the sculpture is uniform, so that the dimensional proportions and tolerances do not change.

After polishing, finally, a sculpture surface is created, which the

Mirror effect achieved and on the sculpture surface with the human eye no discrepancies can be seen. The sculpture can also be coated with coatings, paints or powder coatings such that the gloss of the polish is maintained.

The method according to the invention will be explained in more detail below with reference to a drawing which merely illustrates preferred embodiments.

In the drawing show

1 shows the sequence of the individual sequential steps,

Fig. 2A shows the representation of a used for the scanning

cylindrical coordinate system,

213 shows the representation of a half-spherical coordinate system used for the scanning,

3A to 3F different views of the model or the sculpture and

Fig. 4 is a nachzubehandelnde sculpture in three-dimensional

View.

In Fig. 1 the sequence of steps of the inventive method is shown, while the steps of the 3 D model production on a reduced scale and the

Mirror polishing marked as optional steps. 2A now shows that the model to be imaged, indicated in the example as a cuboid 0, has to be scanned and / or photographed and / or filmed by a plurality of camera positions K in order to obtain a sufficient data density over its surface density.

On the right side of Fig. 1 is an alternative manufacturing process

described in which the mold can be made by means of rapid prototyping immediately after modeling. This way is an even more automated Sequence of process steps possible. In this method too, it may be expedient to first produce a 3D model behind the modeling step, which in turn can be produced by rapid prototyping, in particular by means of an SD printer.

In the embodiment shown in Fig. 2A four concentric and equal circular arcs A, B, C and D are shown and with the reference numerals 1, 2, 3, 4 four are arranged evenly distributed over the circumference of the circular arcs

Camera lines shown, so that in the middle of the coordinate system formed in this way object 0, which in the illustrated

Embodiment shown as a cuboid, however, could be any three-dimensional object, such as a horse, is oriented so that the

Camera line 1 a scanning of the object from its right side, the line 2 it from the front, the line 3 it from its left side and the line 4 allows it from behind The individual K camera positions can be traversed in a motionless or dormant role model in succession. When scanning a live animal, such as a not completely stationary horse, a variety of cameras must be set to get many pictures of a currently ingested simultaneously state of the situation.

2B shows that other arrangements of the camera positions K are also possible, for example on concentric circles Λ ', Β', C and D 'within individual planes El and E2 of a semi-spherical arrangement with which, for example, an object O' is scanned can, whose top is of particular importance.

For a better explanation of the type of scanning, the respective representations of the object O, again a horse in the example, are shown in FIGS. 3A to 3F. Here, Fig. 3A from the camera angle B2, Fig. 3B from the

Camera perspective B3, the Fig. 3C from the camera angle B4 and the Fig. 3D from the camera angle Bl shown. To clarify are between the

Camera lines 1 and 2 in the exemplary embodiment each offset by 30 ° further Camera lines and 1 "so that, accordingly, Figs. 3E and 3F have been photographed from the camera positions Β and Bl".

Finally, FIG. 4 shows that defects detected in quality assurance on the surface of the finished sculpture 0 can be represented by corresponding methods, such as, for example, the dye penetration method, so that possible reworking can be carried out quite deliberately there.

Claims

P a n t a n s p r e c h e

Method of making three-dimensional sculptures after an original one

Object, especially after a living example, characterized by the following steps:

Scanning, d. H. scanning and / or photographing or filming all

Dimensions of the object to create a virtual three-dimensional image,

- Making a model bust or characteristic parts of the sculpture in the

Scale 1: 1,

- design and manufacture of the casting model or casting models,

Producing the mold or molds using the casting models,

- casting the mold (s),

After treatment of the casting or castings

- If necessary, positive and cohesive welding of the individual moldings.

Method for producing three-dimensional sculptures according to an original object, in particular according to a living model, characterized by the following steps;

Scanning, d. H. scanning and / or photographing or filming all

Dimensions of the object to create a virtual three-dimensional image,

Modeling, ie processing or editing of individual scans and photos or films to a realistic virtual copy d Making the mold or molds by means of rapid prototyping

Use of 3D data from modeling and computational

Simulation process,

Casting the mold (s),

- aftertreatment of the casting or castings,

- If necessary, positive and cohesive welding of the individual moldings.

Method according to claim 1 or 2,

characterized in that s

After modeling a miniature 3 D model is produced.

Method according to claim 3,

characterized in that s

the production of the model is done by freeform surface milling.

Method according to claim 3,

characterized in that s

the model is produced by rapid prototyping.

Method according to one of claims 1 or 3 to 5,

characterized in that s

the model bust or characteristic parts or the miniaturized models are coated with a special metal / plastic coating.

Method according to one of claims 1 or 3 to 6,

characterized in that s

for the calculation of the casting model arithmetical form and

Solidification simulations are performed. Method according to one of claims 1 to 7,

characterized in that s

the finished gestaltten / n form / s for a defined duration to a predetermined

Temperature is / is heated.

Method according to one of claims 1 to 8,

characterized in that s

Quality assurance takes place after casting aftertreatment.

Method according to claim 9,

characterized in that s

a surface inspection is carried out according to the dye penetration method.

Method according to claim 9 or 10,

characterized in that s

a post-processing of the defects takes place

Method according to claims 1 to 11,

characterized in that s

the sculpture is cast in stainless steel.

13. The method according to claim 9 to 12,

marked by

a surface treatment by mirror polishing the finished sculpture.

14. The method according to any one of claims 1 to 13,

characterized in that s

the finished sculpture is coated with varnish or a fulver coating in such a way that the polish shine is permanently preserved.