Production instructions mean full description and instructions concerning raw material, operating conditions, and process to be employed for the manufacture and assembly of the product. This includes also skills and tools needed for manufacture and assembly.
Technical documents provide the source needed to study and replicate a hardware design. In contrast to project documentation and community building, technical documents for OSH are quite specific, but can be considered analogous to what source code is for software. Depending on the project, technical documents may include technical drawings, images describing electronic schematics, computer-aided design (CAD) files, or assembly instructions to replicate the design. A thoroughly documented project will have all types of documents. It may also include code (firmware and software) necessary to run the hardware. The source files (like CAD files) are best accompanied by textual and multi-medial documentation, such as guides for manufacturing, assembly, maintenance, and development.
Production usually starts with the sourcing of material, and a bill of material (BOM) is required. It describes all the components and their references. If the component is to be purchased, one should find all the information required to buy the part. If the part is to be manufactured, one should find all the descriptions of the manufacturing instructions, as well as all the components needed for this manufacture (for instance, The BOM should report the amount of PLA needed when parts are 3D-printed).
Relation to structural modeling
Technical documents include both the structural modeling and the production instructions, they provide the source needed to study and replicate a hardware design. In contrast to project documentation and community building, technical documents for OSH are quite specific, but can be considered analogous to what source code is for software. Depending on the project, technical documents may include technical drawings, images describing electronic schematics, computer-aided design (CAD) files, or assembly instructions to replicate the design. A thoroughly documented project will have all types of documents. It may also include code (firmware and software) necessary to run the hardware. The source files (like CAD files) are best accompanied by textual and multi-medial documentation, such as guides for manufacturing, assembly, maintenance, and development.
Following the guide for structural modeling, one should share both raw and derived source files. For instance, 3D object designs should be shared as print-ready files (.stl file for instance), but also as modifiable 3D objects (the format of these files will depend on the software used). It is necessary to provide the raw files to enable modification, even if they can often only be opened in proprietary software, and their use requires specific skills. The derived versions are used to build the hardware, but often are not suited for modification. Users with access to the tools that can read and manipulate these raw source files can update and improve the physical device. If they wish, they can proceed to share such modifications.
Production instructions
Production instructions should include:
A bill of material (BOM): it gives an overview of all the material that needs to be sourced and/or manufactured, and describes all the components and their references: Section 8.4
Manufacturing information: they can guide the makers to follow a process for replicating a product, and mean full description and instructions concerning raw material, operating conditions, and process to be employed for the manufacture of the hardware parts.
Assembly instructions: they can guide the makers to follow the process of assembly or disassembly of components of a product, and illustrate visually and with words and text how to assemble or disassemble the mechanical and electrical components of the product.
If relevant, the electric and electronic plan should be provided (Section 8.7). Note that firmware and software installation (described at Section 8.8 ) may be included in the assembly sequence.
Helping workflow and software
It is sometimes easier to create a guide for manufacturing and assembly. For instance, using the Gitbuilding software, one can write the manufacture and assembly instructions, and when using specific tags for tools and material, the software creates BOM, part lists and tool lists for each step and for the whole project.
A bill of materials (BOM) is a comprehensive list of parts, items, and other materials required to create a product, as well as instructions required for gathering and using the required materials. If the component is to be purchased, one should find all the information required to buy the part. If the part is to be manufactured, one should find all the descriptions of the manufacturing instructions as described below.
A bill of material usually includes:
Part number
Item name
Manufacturer part number
Digi-Key part number
Description
Manufactured part (link to manufacturing instruction)
Purchased part (link to seller website)
Quantity
Price
Manufacturing standard lead time
Packaging instruction
BOM notes
Modularisation
When there are multiple parts, it is best practice to have a BOM for each part, and one BOM for the whole hardware. For complex project, it is therefore best to create BOM automatically. Some software are meant to created BOM from the CAD files (CAD-coupled documentation, https://doi.org/10.5334/joh.56) or from the assembly instruction (using Gitbuilding).
Summarise what materials have been used to construct the hardware and what methods to process the materials (as well as the assembly). Provide more details or references where important materials or methods are non-standard, not globally available, or produced only by one manufacturer.
Here comes the elements that were more briefly described in Section 5.3. Since software/firmware development follows different practices that often needs a more detailed version control system, they are usually developed independently of the hardware.
Any code or firmware required to operate the hardware should be shared. This will allow others to use it with their hardware or modify it along with their modifications to your hardware. Document the process required to build your software, including links to any dependencies (for example, third-party libraries or tools). In addition, it is helpful to provide an overview of the state of the software (for example, “stable” or “beta” or “barely-working hack”).
In all cases, it is important to keep track of which version of the soft/firmwares are used with which version of the hardware.
Also indicate details on the operating software and programming language, and include minimum version compatibility, and dditional system requirements, like memory, disk space, processor, input or output devices.
The Airtrack hardware was developed using pixycam. The hardware and the software are developed in different repositories with different people involved. In 2025, as the pixycam was not produced anymore, a new version of the hardware was created, using the pixycam2 component. This had little effects on the hardware design, but, the firmware and software needed to be modified.
What is the specific knowledge a maker shall own to manufacture the different parts of the hardware ?
Product build: Manufacturing tool
Manufacturing tools means all the machinery, equipment, and processes used to manufacture products. Manufacturing technology guide to find the type of necessary technology to produce the part. In that case, it should describe the most suitable technology according to the context.
Type of machines
Type of machines used
CNC machine tools for machining metal or other rigid materials
The Manufacturing sequences refer to step-by-step machining and manufacturing processes in a target-oriented arrangement to enable manufacturing.
- The machining sequence should define for the manufacturing of each part.
- Process parameters are all those parameters that are inherent to any machining operation and should have a suitable finite value to smooth and efficient removal of materials.
- Manufacturing standard file formats support some of the manufacturing processes and the surface geometry of a design without the possibility of modification.
What does include the documentation of manufacturing sequences and instructions?
Name of the related machine of each step
Describing step by step sequence of the machining process - Machine - Type of operation - Tools description - Process parameters of each machining operation
Process parameters of 3D printing
Process parameters of Laser cutting
Process parameters of CNC machines such as Lathe, Milling, etc.
Process parameters of arc welding
Raw material (including size if relevant)
Manufacturing files (STL, SVG or G-code, …)
CAD files in an interchange format such as STL that is suitable for 3D printing
Nominal geometry and its allowable variation by using symbolic language on 2D drawings like SVG, JPEG, and PDF format that is suitable for laser cutting
Manufacturing export formats such as G-code, STEP-NC is suitable for CNC machining
Circuit board design formats such as Gerber RS-274X, excellon that is suitable for vector photoplotters 2D mechanical NC machines
To help others make and modify your hardware design, you should provide instructions for going from your design files to the working physical hardware. It is good to publish annotated photographs (or video) from multiple viewpoints and at various stages of assembly. If you do not have photos, posting annotated 3D renderings of your design is a good alternative. Either way, it is good to provide captions or text that explain what is shown in each image and why it is useful.
The Assembly sequence usually start with a description and list of each part that will be assembled, and then provide a step-by-step guide. One can think of instruction for lego objects (In these special case, the part list is identical to a BOM and placed at the end).
See Chapter 8 for information about software and dependence with guide for manufacturing.
Part list
The Part list for mechanical parts is a complete list of all parts needed to build the complete product. It is different from the BOM which list material needed for the manufacture of the parts, while this document list the manufactured parts.
It constitutes of : - Item numbers: are based on the assembly structure, that is, the order in which parts are displayed in assembly. - Part number or drawing number: which is a reference back to the detail drawing (refer to the BOM). - Description: is usually a part name or a complete description of parts. - Quantity is the number of that particular part used on this assembly. - Image (or STL render) of each part.
Sequence
The set of steps necessary to properly assemble the parts should be well described at each step.
The joining technology at each step should be clearly described: - Screwing - Bolting - Soldering - Gluing (or “gluing and screwing”)
It is good practice to design the parts such that the assembly is easier. One can for instance include the item number on the parts and make sure that it is difficult to assemble parts at the wrong step, for instance by designing asymetrical parts.
You may indicate any measures that have been taken in the design to make the hardware easy to build for other users (reduction of parts, features in the design to make the hardware assembly more reliable, …)
This document should provide information about the specific knowledge a maker shall own to assembly the hardware product, and what tools are necessary. For example, one can report how many people are needed to assemble the hardware.
Example of skills and machines:
Required skills for assembly
Operate drilling machine
Operate Band Saw/Dremel
List of the tools for assembly or disassembly
Mandatory
Allen Keyset
Imperial wrench set
Optional
Drill press
The skills can be listed by name and a description. In many case, it might be interesting to link skills with tools, as being able to operate each tool is a needed skill.
Example
To build the Airtrack, it is optional to use specific UV glue and its specific equipment. One should nevertheless have some experience in using plastic glue.
