When the library isn't enough

In BWF2 you built products by picking blocks off the shelf. But real products often need something the shelf doesn't hold — a new combination of blocks, a tighter cost or size target, or a shape no domain design covers. That's custom design, and it's where product development gets interesting.

Custom doesn't mean "on your own." Forge still helps in two ways:

• It composes custom circuits by combining many subcircuits into a product no single block describes.
• It offers a freeform / parametric path for enclosures and parts that don't match any domain design — geometry built to your dimensions rather than a preset.

What changes at this level is you. You stop accepting the first answer and start directing it: setting the requirements, reading the BOM critically, budgeting the power and the cost, and iterating the shape until it's right.

This module walks that arc — custom circuit, custom enclosure, designing for real manufacturing, iterating — and ends with a capstone where you take a product of your own from idea to buildable.

Amateurs start with a shape or a part they like. Professionals start with requirements — a short, honest list of what the product must actually do. Everything downstream is a consequence of it.

A good requirements list answers:

• Function — what must it sense, decide, and do? (The input → brain → output from BWF1.)
• Power — plugged in or battery? If battery: how long must it run between charges? (That sets a power budget.)
• Size & form — must it fit a pocket, a wall, a desk? Any hard dimension limits?
• Cost — what's the target price, in naira? This constrains parts more than anything.
• Environment — indoors, outdoors, wet, hot, knocked around?

Write these down before you open Forge. Then your prompt carries them ("...runs a week on a battery, under 20,000 NGN, outdoor") and the whole design is aimed at the target from the first pass.

Skip this step and you get a design that's a product — just not your product.