Laser Used in Model Making

Model Making

A model is a 3-dimensional visual tool designed to answer questions and solve potential problems by making it easy for lay people to understand a complex project. Each completed scale model is considered a functional work of art by the maker, unique in details and recognized by its creativity and the quality of craftsmanship.

No two models alike, however, a number of companies produce ready-made pieces for “structural components” (e.g. girders, beams), siding, and “scenery elements” like figures (people), furniture, vehicles, trees, bushes and other features used in the models.

Who Makes the Models?

Architects do not make models; instead they employ a professional model maker or pattern maker to create models. While some of the larger architectural firms do employee model makers and have their own model making equipment in house, most work is outsourced to contract shops and individuals who specialize in making models and patterns.

A model maker is a craftsperson who creates a 3 dimensional representation of a design or concept. This "model" may be an exact duplicate of the design or a simple mock-up of the general shape or concept. Many prototype models are used for testing physical properties of the design, others for usability and marketing studies.

A pattern maker is generally thought of as one who makes originals of a design to be molded by some method. Patternmakers generally work in wood to make their parts. The original that is made might be called the model, master or pattern, depending on the industry involved.

A fabber (short for “digital fabricator”) use computerized equipment that makes things automatically from digital data. These fabbers use specialized equipment such as rapid prototyping machines that generate three-dimensional, solid objects you can hold in your hands by the process of selective curing, selective sintering or aimed deposition.

There seems to be some interchangeability in the use of the term “model maker” and “pattern maker”, but the work involved is general the same. The use of one term or another has more to do with the traditions of the industry involved.

Model makers or pattern markers are those most likely to use laser machines. However recently we have seen a number of fabbers that are purchasing laser cutters and laser engravers to enhance their finished product. These three skilled groups, the model makers, pattern makers and fabbers are those people most likely to have a working understanding of computer aided design (CAD) and computer aided manufacturing (CAM).

Materials Used

Traditional materials used for architectural model building include vellums, card stock, balsa wood, and basswood as well other woods. Recently it is more common to find materials such as Taskboard, a variety of plastics, wooden and wooden-plastic composites, foams and urethane compounds.

Basic Processes

There are four basic processes to create models:

Additive. This process can be as simple as adding clay to create a form, sculpting and smoothing to the final shape. Body fillers, foam and resins are also used in the same manner. Most rapid prototyping technologies are based on the additive process, solidifying thin layered sections or slices one on top of each other

Subtractive. Subtractive has been compared to the act of whittling a solid block of wood or chiseling stone to the desired form.

Formative. Material is neither added nor removed, but opposing pressures are applied to the material to bend, stretch, compress or otherwise modify its shape.

Hybrid. Processes from two or more of the above categories are combined. Sheet-based fabbers, which cut and laminate successive layers of sheet material, are hybrid subtractive/additive devices. A combination CNC punch press and press brake is a hybrid subtractive/formative fabber.

Cutting and engraving lasers

The cutting and engraving lasers that we sell are subtractive, progressively using the laser beam to remove material from a rough shape to get to the level of detail desired in the final model.

The cutting and engraving lasers that we sell are programmed using a computer software package software tool called EngraveLab. EngraveLab is a program that is generally similar to other CAD packages currently in use within the model making industry.

The challenge to the operator using and CAD/CAM tool lies in proper programming, in the creation of the CAD file format. The laser will faithfully reproduce any pattern that it is programmed to complete. This fidelity requires that the CAD file tool path must be cleanly produced, optimized and safely stored on the computer which is used to operate the laser cutting systems

Clean optimized tool paths are the major challenge for architecture models produced using this technology. We offers several solutions to make this optimization of tool paths easier.

When to Use a Laser

There are four criteria that determine whether a project is appropriate for a laser:

1. Low to medium volume

2. The profile of the end product is available as digital data in computerized form

3. The desired shape is complex

4. The ability to make rapid changes is required

In this list, the first two criteria are the most important. A laser cutter is not appropriate for direct high-volume production (although it can be used to make a “copy tool” called a mold or pattern which can then be used to make large quantities of a product or part), and it cannot be used without computerized shape data. The third and fourth criteria are optional but help determine the need for using a laser. The more precise, detailed and complex a shape is the more pronounced is the benefit of using a laser cutter or engraver.

Why Use a Laser

Some of the advantages of lasers over other means of subtractive processing are:

  • Direct generation of product based on digital data, without the errors arising from a tradesman’s interpretation of the designer’s drawings

  • Ease of repetition. Any part of the design can be changed as required and the object refabricated without the need to redo the entire design of the object.

  • Accuracy and repeatability of dimensions on the order of 5 to 15 microns (0.0002 to 0.0006 inch)

The advantages of using lasers in design and production applications can be dramatic. Manufacturers have typically realized time and cost savings of 50 to 80 per cent in product development, and even greater cost savings and schedule reductions are not uncommon.

Along with reduced cost and development time, the practical ability to rapidly create, control changes to designs always leads to improved final product quality. The ability to turn a new idea into a final product quickly can cause a stir of excitement and professional satisfaction in the product team. This in turn feeds back to high productivity and quality of performance from the individuals involved.