Throughout its evolution, our industrial economy has hardly moved beyond the linear consumption model of ‘take-make-use-waste’. Alternative systems, such as the circular economy, are suggested to overcome the challenges of the linear economy. It proposes a restorative way of consumption where materials, products and parts are kept longer in use and no waste is generated. Repair helps to slow down the resource loops, with the added benefit that the required investments are lower than for other recovery options. However, spare parts may not be available when the production of the products ceases as it is difficult to predict how many spare parts are needed and storing them in warehouses can be costly. To make spare parts more generally available, they could be produced with additive manufacturing. Printed spare parts can be stored online instead of in a physical inventory, reducing delivery time, costs, emissions, and material waste. However, to fully optimise printed spare parts, a better understanding is needed of the design considerations that are involved.

In this dissertation, we explore how additive manufacturing can be used to produce plastic spare parts for the repair of consumer products. By reviewing the repairs of consumer products in repair café’s, we estimate that around 8-29% of plastic spare parts are currently suitable for additive manufacturing. As most parts are currently unsuitable for additive manufacturing, the design of these printed spare parts needs to be aligned with the capabilities of the technology. This requires a better understanding of the specific design considerations. We need to find what design aspects are suitable for the use of additive
manufacturing and which are more difficult. This will help us to determine the design complexity and what the biggest design challenges will be. Also, we investigate how to design parts that facilitate the use of additive manufacturing. Since parts can be designed by either the consumer or the manufacturer, it is important to distinguish between design in consumer self-repair and in manufacturer-enabled professional repair. These design perspectives are explicitly included in this dissertation.... ... Read more

Using additive manufacturing for spare part production can ensure that spare parts are available for a long time. However, spare parts are currently not designed for additive manufacturing. This study aimed to find how the production of 3D-printed spare parts can be facilitated in the design of plastic parts. We used a literature review and illustrative case to find how the design requirements for standard injection moulded plastic parts relate to the manufacturing capabilities of additive manufacturing for spare parts. The design requirements were defined by assigning corresponding structural and material properties. These requirements were then used to construct and evaluate the capabilities of additive manufacturing compared to injection moulding. It was found that additive manufacturing is especially suitable for requirements like Accuracy, Heat resistance, and Chemical resistance. However, to fully enable 3D-printed spare parts, certain design challenges still need to be tackled. Designers should pay careful attention to the synergies and trade-offs between design requirements and the challenges that might arise from the combination of certain requirements. Also, designers should ensure products are easily reparable before considering 3D-printed spare parts. If we target these challenges in the design phase, we can facilitate 3D-printed spare parts that enable product repairability. ... Read more

The availability and storage of spare parts are the main barriers to product repair. One possibility would be to 3D print spare parts, which would also enable the repair of products not intended to be repaired. Besides manufacturers, 3D printing spare parts is an interesting option for self-repair by consumers. However, the digitisation of spare parts for 3D printing is a challenge. There is little guidance on how to make a 3D-printed version of the original part. This paper establishes a framework through a literature review and experimental study to describe how to use 3D printing to produce spare parts for repair. Additionally, qualitative data coding was used to find the influence of previous experience, process implementation, and part complexity on the overall success of the 3D printing for repair (3DPfR) process. Our study showed that the 3DPfR process can be described as an iterative design for an additive manufacturing process that is integrated into a repair process. Additionally, it was found that the incorrect implementation of process steps was the most important predictor of the repair result. The steps that were performed incorrectly the most were synthesising design concepts (64%) and validating print quality (also 64%). ... Read more

Spare parts availability is crucial for extending the life of consumer products. However, long-term availability could lead to high stocks of spare parts, which might not be used. Instead, on-demand manufacturing of spare parts with additive manufacturing (AM) is a promising alternative. This paper presents a method to evaluate parts on their eligibility for AM spare parts. The parts evaluation is based on AM technology accessibility as well as part requirements. This method was tested by assessing all parts of the Dyson V11 broom-stick vacuum-cleaner and validated by printing and testing a selection of parts. For this, both plastic and metal spare parts were made through fused deposition modelling (FDM), stereolithography (SLA), binder jetting (BJ), material jetting (MJ), selective laser melting (SLM), selective laser sintering (SLS), and multi jet fusion (MJF), using both desktop FDM printers and off-site service providers. Based on these results, we conclude that currently only a small number of parts can be replaced by additive manufactured parts without considerable redesign efforts. AM parts can compete on price with the current stocked parts, but may be more expensive for other products. We also identified additional functional requirements for evaluating the eligibility of a spare part for AM. ... Read more

The Sharepair project aims to decrease the waste of electronic and electric consumer products and increase their useful life, by supporting repair communities and scaling up citizen repairs through digital tools. One of the focus areas of this project is to support the discovery or manufacturing of spare parts. With a 3D CAD model of a part and a 3D printer, repair communities could manufacture spare parts. This paper discusses the possibilities of identifying repairs, within repair communities, that can be met through 3D printed spare parts. To understand and identify these possibilities, the repair entries expressed in the Open Repair Database (ORD) from the Open Repair Alliance were examined. The analysis aimed to identify documented examples of repairs that have broken or missing parts, and estimate how many may be suitable for replacement by 3D printed versions. The ORD includes 41,874 repair data entries from 229 repair communities (Repair Café, Restart Project, Fixit Clinic, and Anstiftung) in eighteen countries. Repair entries include information such as product category, brand, model, repair status and notes regarding the repair process and result, all in different languages. The analysis identified a list of the most commonly repaired product categories, brands, and models, as well as an estimate that between 7.5% and 29% of products in repair cafes that are not repaired today could be repaired with 3D printed spare parts. The analysis also showed that the data and information about the repairs is inconsistent, open to interpretation and often too limited to precisely pinpoint opportunities for 3D printed spare parts. Specifying the product parts that need repair or replacement and their functional requirements would be key to a successful identification. Thus, the study proposes recommendations to improve the process of capturing repair information that specifies the repair needs that can be met by the use of 3D printing. ... Read more

This guide takes the reader through the 3D Printing for Repair (3DP4R) process. It consists of guidelines and tools to create a 3D printable version of spare parts needed for a product repair. 3D printing a spare part is more than just printing the original part. Instead, it is an iterative process in which the part is analysed, redesigned, manufactured, and tested, in order to come to a final part. This guide will describe these four phases in detail. The guide is meant for anybody who is interested in trying to manufacture spare parts with 3D printing technologies, remakers, tinkerers, volunteer repairers, professional repairers, and everyone who is interested in repair initiatives. ... Read more