Prototyping suitable for serial production

Delivery in 3 to 4 weeks!

CIREX uses several prototyping techniques for steel parts, tailored to individual client demands. Our expert team has ample experience in the production of prototypes for various industries and applications:
A prototype should be more than just a replica of your component or 3D model. It must be able to easily withstand functional tests, through which requirements such as tensile strength, hardness and shape retention can be validated properly. A good and functional prototype is a fundamental step to reach a successful transition from concept/prototype phase to serial production. CIREX delivers your “Form – Fit – Function” prototypes in 3 to 4 weeks!

Prototyping techniques for the lost-wax process – any steel alloy is possible

The choice of most effective prototype process is determined by the desired mechanical properties that the final component must meet and the tests that it must pass. These requirements will reduce the number of prototyping options available. That is why CIREX offers prototyping techniques without the need for concessions: your product can be cast in any desired steel alloy. We use various prototype techniques that can be applied in the lost-wax process, as replacement for a wax injection mould, to ultimately deliver a steel prototype. These parts are cast according to the serial process, so that the mechanical properties are representative for the final serial production process.

3D printing wax models

If you are looking for an effective method to validate your 3D design (proof of concept), this technique is a solid option. CIREX uses printed wax models based on a 3D design. This negates the need to invest in wax injection moulds, as a result of which the start-up costs are significantly lowered. These wax models are then attached to the wax tree. The remainder of the production process proceeds as it would in the final serial production, resulting in a well-functioning steel prototype with high-quality mechanical properties.

Characteristics:

  • Quick turnaround – printed within a few hours;
  • High degree of dimensional precision;
  • High surface quality;
  • Suitable for small runs;
  • Product can be cast in any steel alloy;
  • Printing wax models is more expensive than injection moulding;
  • Limitation: our printers can process fist-sized and smaller parts.

3D printing PMMA models

Using our Rapid Prototyping printers, the printing of plastic polymethyl methacrylate (PMMA) models only takes a very short time. These PMMA models are an exact copy of the 3D model you provide. PMMA models are similar in structure to PLA models and are suitable for larger parts, even when these exceed the maximum dimensions of wax models and PLA. The PMMA models are given a ceramic outer layer, after which the models are burned out, leaving no residues in the ceramic mould.

Like 3D wax printing and PLA, PMMA is suitable to validate the 3D design using strength and/or endurance tests, for installation tests regarding fit and geometry, and to perform specific surface treatments.

Characteristics:

  • Quick turnaround – printed within a few hours;
  • Lower degree of dimensional precision than 3D wax printing;
  • Higher surface roughness than 3D wax printing;
  • Suitable for small runs;
  • Product can be cast in any steel alloy;
  • PMMA models are cheaper than printed was models;
  • PMMA allows printing larger models than when using wax models or PLA.

3D printing PLA models

Polylactic acid, also known as PLA, is a sustainable alternative for traditional plastics. PLA filament is made from biodegradable and renewable resources. As a filament type, PLA is easy to use and is suitable for printing very detailed objects.

We use an FDM 3D printer for printing PLA. With fused deposition modelling technology, a model is printed by an “extruder”, layer by layer. Because the models are not printed as solids, we can easily incorporate them in our process. The main advantage of this technique is the speed and the relatively low costs. This makes PLA models extremely suitable for functional testing of a casting. When a high dimensional accuracy or surface roughness is required, it is better to choose a different technique, such as printed wax models. PLA models show great similarities to PMMA models.

Characteristics:

  • Quick turnaround – printed within a few hours;
  • Lower degree of dimensional precision than 3D wax printing;
  • Higher surface roughness than 3D wax printing;
  • Suitable for small runs;
  • Product can be cast in any steel alloy;
  • PLA models are cheaper than printed wax models or PMMA models;
  • PLA allows printing larger models than when using wax models, but not as large as with PMMA.

3D printing SLA models

This technique is currently being developed at CIREX and will soon become available.

Injecting wax models using a silicone mould

In addition to printing 3D wax models, there is an alternative to inject wax models using a silicone injection mould. How does this work? We first create a silicone mould from a printed model. Warm silicone fluid is poured over this 3D printed master model. After solidification and cooling, the master model is removed from the silicone. An empty “negative” space is created: this is the silicone mould.

This silicone mould can be filled with liquid wax multiple times. When relatively large numbers of prototypes are required, making a silicone mould is a suitable method, as it can be reused after each casting.

Characteristics:

  • Quick turnaround – mould is available within a few hours;
  • High degree of dimensional precision;
  • High surface quality;
  • Suitable for small and medium-sized runs;
  • Printing wax models is more expensive than silicone mould injections, especially for greater numbers;
  • Investing in a silicone mould is necessary;
  • Product can be cast in any steel alloy;
  • Limitation: the master model mainly determines the quality and dimensions of the wax model.

Injecting wax models using a prototype mould

If you are looking for a prototype process to produce a large quantity of parts with the same mechanical and physical properties, dimensions and tolerances as your final component, then a wax injection mould is the most efficient option. CIREX uses injected wax models that are based on a 3D design. However, it is necessary to invest in a wax injection mould. This increases the start-up costs, but prototypes can be produced at lower unit prices. The use of a wax injection mould is seen as the standard process for crafting wax models, rather than printing wax models or using a silicone mould.

The prototype mould is used to allow the quick and reliable crafting of the first products. After delivery, we receive feedback from the customer on whether any optimisations need to be made to the product design. Changes to this mould are often quick and easy to implement.

Characteristics:

  • Investing in an injection mould is necessary;
  • Long turnaround due to production of wax injection mould;
  • Used for larger-sized runs;
  • Favourable pricing at larger quantities;
  • Crafted from aluminium with manual control;
  • High degree of dimensional precision;
  • High surface quality;
  • Product can be cast in any steel alloy;
  • Injecting wax models is cheaper than 3D printing wax models;
  • Any desired dimensions can be injected using a mould.

Prototyping techniques without the lost-wax process

Besides prototyping that is suitable for the lost-wax process, CIREX also offers other prototyping techniques. In those cases, prototypes are not produced through casting but using alternative production techniques. This allows CIREX to offer a full range of Rapid Prototyping.

Mechanical machining from solid material

Mechanical machining from solid (bar) material is the fastest process for crafting prototypes and additionally offers high dimensional accuracy. This makes the technique more suitable for validating a 3D design for fit (geometry) or for performing mechanical tests, for example.

Prototypes can be machined from different materials. Aluminium is the preferred choice when speed is desired at an attractive price. This allows quick validation of the prototype’s functioning and to check whether the design needs further optimisation. In addition to aluminium, CIREX can also machine steel prototypes from solid material. This also includes stainless steel (SS). Customers often choose steel prototypes if the 3D design has to function under high mechanical loads and/or in an aggressive environment.

Direct Metal Laser Sintering (DMLS)

Direct Metal Laser Sintering (DMLS), also called Selective Lasering Sintering (SLS) or metal 3D printing, is suitable for prototypes with complex geometries that cannot be produced using a mould or machine tool. The products are constructed layer by layer using a 3D printer. The metal powder is applied in layers and sintered to the desired spot using a laser. By repeating this process over and over, the metal product eventually arises.

CIREX has a network of certified production partners for metal 3D printing, so that you can quickly verify your design. CIREX mainly focuses on single items, but serial assignments are possible as well. The advantages of metal 3D printing are the strength and light weight of the design as well as the absence of material loss. Metal 3D printing is widely used in the tooling, medical and aviation industries.

Several advantages of metal 3D printing:

  • Suitable for small runs;
  • Quick turnaround;
  • Complex shapes and complex internal structures possible;
  • Little to no limitations to the design;
  • Use of high-quality materials;
  • Short production cycle;
  • Reduction of weight;
  • Saves materials and energy.

CIREX uses DMLS. You must consider that with this process, the metal prototype does not have the same mechanical properties (i.e.: lower properties) as a cast product. This is due to the fact that the metal powder is sintered, which results in a coarse material structure. Lost-wax model castings use molten steel, creating a finer structure, which makes the mechanical properties a lot better. The photos below show the difference between a sintered and a melted part.

In short, DMLS is a good technique for the validation of the 3D geometry of a prototype, but less so for use in heavy functional tests. A DMLS part will only be able to withstand lighter loads without difficulties.

Get the most out of your prototypes!

One of the most important – and often underappreciated – steps in the prototyping process is to involve your supplier as early in the design process as possible. You preferably want a prototype design with optimal manufacturability. The best way to achieve this is to call in experts who are familiar with prototyping and the lost-wax process.

An expert team of CIREX engineers will meticulously guide your project and advise on the best options of Rapid Prototyping for your specific application. In just a few weeks, your ideas, insights and innovations can be converted into tangible models. This helps speed up your development process significantly. This approach also prevents unnecessary setbacks and design errors in the later stages of the production process.

CIREX will gladly help you with:
• Engineering of your product (function and manufacturability);
• Preparation of the digital 3D models;
• Selecting the most suitable 3D prototyping technique;
• Advice on choice of material;
• Production of 3D prototypes;
• Delivery within 3 to 4 weeks;
• Technical evaluation and optimisation.