Alongside bringing about new ways to make products, additive manufacturing (commonly referred to as 3d printing) opens up new ways to design them. This article explores a speculative model and vision between HCI and Industrial design, where the use of modular and modifiable ‘CAD’ parts coupled with intelligent systems could be used within lay user/retail settings to enable non-designers to create custom functional objects, with limit prior knowledge. Leading to design outputs that can be fabricated by on-site and on-demand additive manufacturing technologies. This article reports on a design workshop where cycling enthusiasts, supported by industrial designers, utilised, configured and modified a range of ‘CAD parts’ to create custom-made functional objects for additive manufacture. The study findings indicate the practicalities and challenges of implementing an ‘HCI system’ for the production of novel functional objects by novice designers, and signposts further investigation. The article yields value to HCI researchers through design-led opportunities, based on technological review and workshop insights; developing sustainable, resilient and independent manufacture. The combination of digital manufacture, design opportunity and intelligent HCI systems offer; new HCI models, distribution, design file access, standards compliance, unique Intellectual Property and building functioning customised parts. The (current) Covid-19 context, reaffirms the researches study offering new and agile opportunities that HCI principles can support and build from. The article makes recommendations, forming a design-led HCI software ‘blueprint’. Including guidelines on: part design, their interoperability, the design to production process, and embedding expertise and failure limitation within this process.