0733 892665 info@prosilas.com
Design tolerances in 3D printing

Design tolerances in 3D printing

Tips & Tricks: What are design tolerances?

Exploring design tolerances in SLS 3D printing

Design Tolerances

Let’s continue our journey into the world of tolerances, this time delving into the concept of design tolerances.

What are they, and how should they be managed? In this exploration, we will unveil the crucial role of tolerances in engineering, design, and the production of mechanical components.”

Why using tolerances?

The use of tolerances is a common practice in various industries, and their role becomes particularly evident in ensuring the flawless coupling of components.

But what exactly are design tolerances?

When designing or manufacturing a component, achieving precise dimensions in every unit produced can be a challenge.

Materials, subject to variations in temperature and other factors, can expand or contract. This is where tolerances come into play, defining the limits within which a specific dimension can vary without compromising the functionality of the part.

Prosilas Contribution

At Prosilas, our expertise in manufacturing processes, tolerances, and materials allows us to provide valuable input during the design phase.

Our targeted advice supports engineers and designers in achieving optimal results, ensuring the proper functioning of the parts

Managing Tolerances in 3D Printing

When dealing with the 3D printing of two parts intended to mate, recommended tolerances typically range around one-tenth to two-tenths of a millimeter. These targeted specifications ensure precise mating/fitting, eliminating potential issues of unwanted play.

If the component involves movable sections or joints and requires integrated printing, suggested tolerances increase to around three-tenths of a millimeter.

This distance takes into account the presence of unsintered powder between surfaces and the heat generated by the machine, preventing unintended fusions between moving parts.

Rapid prototyping and 3d printing

Rapid prototyping and 3d printing

The first physical output of a project

Rapid prototyping constitutes the initial phase of the physical production of a project, leveraging advanced technologies such as 3D printing.

Prosilas stands out as a leader in the field of rapid prototyping and additive manufacturing for over twenty years.

Prosilas stampe tridimensionali in carbonmide per prototipi rapidi

Photo courtesy : Bimota 

Photo courtesy : Armotia

Prototype: Definition and Utility

A prototype is the physical realization of an idea or project, an initial model created to evaluate both the aesthetic and functional aspects of an application.

What is Rapid Prototyping?

Rapid prototyping is the process of quickly creating a physical model of an idea or project.

This model, called a prototype, provides a tangible and visual representation of the application in the development phase. 3D printing has become a key technology for rapid prototyping due to its ability to rapidly translate digital designs into physical objects.

The primary purpose is to expedite the development process, enabling a comprehensive assessment of the performance and form of the product.

In Which Cases to Use Rapid Prototyping?

It is particularly useful in the early stages of designing and developing new products.

It is ideal when there is a need to quickly assess aesthetic aspects, optimize geometries, improve production cycles, and evaluate functional aspects.

Furthermore, it is valuable when exploring different iterations of a design without having to invest in expensive molds.

Advantages

  • Reduction of Development and Production Times: 3D printing allows for the rapid translation of designs into physical prototypes, significantly reducing development times.
  • Cost Reduction: By eliminating the need for expensive molds, rapid prototyping with 3D printing helps contain costs in the design and development phase.
  • Improvement of Product Quality: The ability to assess aesthetic and functional aspects in an early phase enables continuous improvements to the final product’s quality.
  • Production Evaluation: With the initial step of prototyping, subsequent steps for mass production can be evaluated, allowing assessments of timelines and costs.

3D Printing Technologies for Rapid Prototyping:

There are various 3D printing technologies suitable for this service.

Among these, SLS (Selective Laser Sintering) and SLA (Stereolithography) are often used for creating prototypes with precise details.

Other approaches, such as using filaments or metal powders, offer different options based on the project’s requirements.

We provide our technological offerings based on project needs and assist the client in choosing the best solution.

Photo courtesy : Bimota 

Case History Bimota

Bimota utilizes rapid prototyping in collaboration with Prosilas to expedite the development of its new motorcycle models.

Thanks to 3D printing, the design and testing process has become more efficient, reducing the time required to transition from the idea to the prototype from approximately 12 to 4 months.

Dimensional Tolerances

Dimensional Tolerances

Tips & Tricks: What are Dimensional Tolerances?

Dimensional Tolerance in SLS 3D Printing: Management and Control by Prosilas

 

 

Dimensional Tolerances

3D printing has revolutionized the way products and components are manufactured, offering unprecedented flexibility and customization.

Even in this innovative technology, dimensional precision is a crucial aspect, and Selective Laser Sintering (SLS) stands out for its ability to produce parts with remarkable precision.

Dimensional tolerance refers to the possible deviation within which the printed part can vary from the original geometry.

Specifically, we are talking about +/- 0.3 millimeters for parts up to 100mm and +/- 0.3% for larger dimensions.

Photo courtesy Protototal Industries

Thermal Expansion

This difference between the nominal dimensions in the 3D file and the printed part is due to thermal expansion, an intrinsic phenomenon in SLS technology.

This printing methodology involves heating the materials to their melting temperature, such as 170°C in the case of polyamide.

During the subsequent cooling process, the part transitions from the melting temperature to room temperature, contracting by approximately 3%.

Our Approach

The parts are initially processed with larger dimensions, using scaling factors specific to each machine and material.

The determination of these factors occurs through the periodic production of samples, a practice that allows monitoring and maintaining control over the dimensional tolerances declared to customers

L'approccio di Prosilas consiste nel produrre parti inizialmente con dimensioni maggiori, utilizzando fattori di scalatura specifici per ciascuna macchina e materiale.

To achieve the highest level of precision, we incorporate this element during the job preparation stage.

Quality Standards

Thermal shrinkage is not entirely constant; hence, an average of the results is calculated and applied.  This phenomenon can vary depending on various parameters, such as cooling times, part orientation, shape, and thickness.

To ensure maximum precision, we integrate this aspect during the job preparation phase. Geometries are carefully modified in the software, taking into account the inevitable dimensional variations that occur during material cooling.

This proactive practice demonstrates our commitment to providing 3D-printed components that strictly meet the quality standards required by our customers.

Per garantire  il massimo della precisione, integriamo questo aspetto durante la fase di preparazione dei job.

The software undergoes meticulous modifications to the geometries, considering the inevitable dimensional variations occurring as the material cools.

BASF Forward AM + Prosilas: Validation of TPU88A in Ultrasim® Lattice Engine software

BASF Forward AM + Prosilas: Validation of TPU88A in Ultrasim® Lattice Engine software

BASF Forward AM + Prosilas Case History

A highly productive and longstanding collaboration has been established between Prosilas and BASF Forward AM over the years. This partnership has given rise to esteemed projects, including the research and production of Philipp Plein’s Skeleton Sole and the comprehensive Lube Volley Case Study.

When BASF Forward AM approached us for cooperation, we welcomed the opportunity with great enthusiasm.

Our involvement centered around the characterization of 3D printed lattice structures made of Ultrasint® TPU88A from BASF Forward AM. It aims to offer users pre-selected, validated lattices in Ultrasint® TPU88A on SLS machines to get a head start in their lattice application development.

For this, the validated lattices will be integrated into BASF Forward AM´s lattice ecosystem consisting of Ultrasint®TPU 88A Lattice Test Pads, Ultrasim® Lattice Library, and Ultrasim® Lattice Engine.

Prosilas will provide excellent print service with an in-dept know-how on printing lattice structures.

Prosilas successfully and expertly utilizes BASF Forward AM´s Ultrasint® TPU 88A. Annually, we process approximately 2000 kg of this TPU in our SLS machines.

Ultrasim® 3D Lattice Engine

What is Ultrasim® 3D Lattice Engine?

 

Ultrasim® 3D Lattice Engine, powered by Hyperganic, is a software application designed to efficiently populate geometric volumes with lattice structures. To achieve this, the software incorporates two key inputs: the STL file of the component requiring lattice infill and a pressure map for performance modulation.

Users can select the specific lattice structure type and hardness parameters from either the 3D printed Lattice Test Pad database or the Ultrasim® Lattice Library, a library containing all characterized lattice structures with in-depth mechanical data.

 

Upon making these selections, the software autonomously generates the chosen lattice structure within the specified volume. This process renders the file ready for subsequent 3D printing operations.

What is the Ultrasim® 3D Lattice Library?

All the results of the lattice characterization is stored in a library named Ultrasim® 3D Lattice Library. This library allows users to filter lattices by application (Footwear, Protection, Seating), by technical requirements and compare the strain-strain curves for different lattices structures. This way users can much easier find and identify the right lattice. Here you find more information about the library: Ultrasim® 3D Lattice Library​ .

Exaples of Lattice structure

Lattice Test Pads

What are the Lattice Test Pads, and what is their purpose?

Lattice Test Pads are the 3D printed version of the are Ultrasim® 3D Lattice Library.

They are 3D-printed TPU blocks divided into sections that specify the cell size and beam diameter. Each section provides information regarding the structure classification and hardness.

These Lattice Test Pads come in three types: footwear, seating, and protection. Each type features a lattice structure suitable for its respective application, such as shoe soles, seat cushions, headrests, or various protective elements.

TPU: incredibly flexible material in every sense

It is a thermoplastic material widely utilized in SLS 3D printing due to its exceptional elasticity, rebound, durability, and resistance to tearing, fatigue, and abrasion.

Lattice structures are repeating patterns composed of cells, beams, and nodes that aim to replace foam applications using a single material but different shore hardnesses.

There are countless variations of lattice structures, each exhibiting distinct mechanical behaviors.

Based on an in-depth study of TPU lattice structures, BASF Forward AM successfully characterized and validated lattice structures based on their behaviour for various applications.

This validation allows to pre-select lattices application in various industrial sectors, namely Footwear, Protection, and Seating.

Three types of Lattice Test Pads :footwear, seating, and protection

Roberto Nasini, Senior Technician Prosilas 

Contribution of Prosilas 

Prosilas has been involved in the lattice characterization process, providing various prints of the 3D Lattice Test Pad samples that allowed BASF Forward AM to conduct in-depth studies. These data were essential for furthering the progress of the software.

To ensure that the software consistently delivers high-quality results over time, specific machine parameters have been established for the fabrication of these structures. These parameters have been designed to set a printing standard, ensuring that software users obtain consistent and reliable results. This commitment to quality and consistency is crucial for the success and effectiveness of the software.

About BASF 3D Printing Solutions GmbH

BASF 3D Printing Solutions GmbH, headquartered in Heidelberg, Germany, is a 100% subsidiary of BASF. It focuses on establishing and expanding the industrialization of 3D printing applications under the Forward AM brand with advanced materials, system solutions, components, and services in the field of 3D printing.

BASF 3D Printing Solutions operates in an agile structure to create customer value with complete 3D printing solutions, in collaboration with partners, for the most innovative applications. It cooperates closely with the global research platforms and application technologies of various departments at BASF and with research institutes, universities, startups and industrial partners. Potential customers are primarily companies that intend to use 3D printing for industrial manufacturing. Typical industries include automotive, aerospace and consumer goods.

For further information please visit: www.forward-am.com.

Marius Haefele, Basf Product Manager 

What are the NDAs?

What are the NDAs?

NDA: The Value of Confidentiality Agreements at the Heart of a Trust Relationship Between Service Providers and Manufacturing Companies

Confidentiality Agreements, commonly known as NDAs (Non-Disclosure Agreements), are legally significant in the manufacturing industry as they are designed to protect confidential and sensitive information.

NDA contracts are widely used in both the industrial and technological sectors, as well as in research and development, with the explicit goal of preventing the disclosure of sensitive data to third parties without the explicit consent of the information owner.

Managing Industrial Secrets at Prosilas

Prosilas works closely with companies, contributing to the development of projects intended to launch in the market within the next three years. In this context, safeguarding information plays a critical role.

Therefore, we provide support for both prototype component production and mass production, utilizing a comprehensive range of technologies, ranging from complex additive manufacturing and 3D printing methodologies to more traditional injection molding techniques.

Within the Prototal Industries group, we have privileged access to diverse technological resources, occasionally collaborating with external suppliers. This is precisely why it is crucial to extend confidentiality throughout the production chain when exchanging information with colleagues and partners.

 

Cybersecurity: Protecting Information Online

Information communication occurs through digital platforms or by transmitting files via email, emphasizing the relevance of cybersecurity issues.

In this regard, Prosilas consistently invests in enhancing its cybersecurity systems, ensuring adequate monitoring and protection of exchanged information.

Our staff also undergoes continuous specialized training to maintain high-level expertise in this field.

Dedicated Spaces: Protecting “Offline” Projects

Confidentiality is a fundamental pillar of our operations and is ensured through the use of NDAs. However, there are circumstances where a higher degree of secrecy is required. We have dedicated specific spaces within our laboratories, providing access exclusively to authorized personnel. Information security is an indisputable priority to preserve the trust and respect of our clients.