The part you can't buy can exist again.

Only if the campaign reaches its funding threshold. A pledge places a card authorization — the deposit amount ($15–$50 depending on the part) is reserved but not transferred. If the threshold is met, all pledges are captured at the same moment and development begins. Until then, no money has moved.

It doesn't fail on the spot. A campaign that falls short at close first enters an extension — your pledge rolls forward, still just an authorization, while the community works to close the gap. If the extension also falls short, the campaign closes and every authorization is released automatically. You don't need to request a refund because there's nothing to refund — the money never left your card.

We borrow a good reference part from a pledged owner (prepaid, insured shipping both ways), 3D-scan it, reverse-engineer a CAD model, validate it against the original, and manufacture. Everyone who pledged receives progress updates through development.