Primed Design A Cast Iron CAD practice

Primed.Design · A Cast Iron CAD practice
HOME · 01/05
Situation · UK Amazon FBA · 2026

Engineered to outsell white-label.

You already run the business. What you don’t own is the product. We engineer one the factory can’t sell to anyone else. Or we tell you it isn’t worth the spend, and explain why.

Engineered product — CAD render, isometric view
Section 02 · The situation

Why your margins are dropping, and why procurement won’t fix it.

Five sellers ship the same product from the same factory under different brand names. Tooling amortises across all of them. As more entrants join the listing, your share of the tool does not shrink for you. It shrinks for them. The instinct is to negotiate the factory down. That is the wrong intervention.

March 2026 · Field Note

That missing 40p a unit is tooling amortisation. It will not come back.

The gap usually sits in one line of the cost breakdown: tooling amortisation, spread across every seller on the listing. The structural answer is engineering, not procurement.

Read the Field Note →
Section 03 · Qualifier

Is this built for sellers like you?

The practice is calibrated for UK Amazon FBA operators between £20k–£200k per month who already understand the business. We don’t explain Amazon to Amazon sellers. We do bring engineering, freedom-to-operate, and tooling economics that most listings agencies cannot.

For
  • £20k–£200k/month UK FBA operators
  • White-label SKUs in mid-tier categories
  • Operators who can read a margin table
Not for
  • Pre-revenue / idea-stage founders
  • Regulated categories: food, supplements, CE/FCC electronics
  • Operators looking for listing optimisation or ads
Section 04 · Recent work

What this practice has engineered.

Real Cast Iron CAD projects. Not every one was built for Amazon, but the engineering discipline is what transfers when an FBA seller moves off white-label.

All case studies →
CAD render of a bamboo-lidded pill splitter, closed, low front three-quarter view
Medical · Consumer
Bamboo-lidded pill splitter

Industrial design, CAD and design-for-manufacture for injection moulding with a bamboo lid insert. The finish-and-tooling control that turns a me-too SKU into an own-design product.

Polished metallic CAD render of a cast pebble pendant shell
Retail · Accessories
Cast pendant shell

Surface-continuity engineering and CAD for a pressure-cast pendant. Form control at this level is what stops a product being trivially cloned by the next seller.

CAD render of a black injection-moulded camera rear-frame bezel
Retail · Photography
Camera body moulding

Injection-moulding design and DFM for a precise camera frame. The tooling-grade discipline an FBA product needs to ship at volume and hold tolerance.

Section 05 · Methodology

How an engagement works.

Phase · 02 · 03 · 04 Weeks 01–03

Discover

Edge Sprint. Margin decomposition, freedom-to-operate scan, four-outcome verdict.

Phase · 06 · 07 · 08 Weeks 04–17

Engineer

Cast Iron CAD Design Phase. CAD development on tooling, supplier brief, cost-per-unit projections.

Phase · 09 Weeks 18+

Deliver

Manufacture, FBA inbound, post-launch advisory. The Manufacture Phase takes it from here.

Section 06 · The on-ramp

£1,250 + VAT for a 1–2 week paid diagnostic.

A published deliverable, not a sales call. Four-outcome assessment with the data behind it, including outcomes “remediate first” and “don’t proceed.” Three sprints per quarter.

EngagementEdge Sprint
Window1–2 weeks · next window Q3 2026
Fee£1,250 + VAT, paid at booking
Output14–18 page PDF dossier · signed
OutcomeA / B / C / D recommendation
Deliverable · what you get

On delivery, signed by Dave Lock.

  1. 01Margin decomposition on current SKUs
  2. 02Freedom-to-operate scan on category
  3. 03Engineering brief (if proceeding)
  4. 04Four-outcome decision strip with verdict
  5. 05Hand-off pathway to Cast Iron CAD
Section 07 · FAQ

Frequently asked.

How is this different from an FBA agency?
We are an engineering practice, not a marketing one. We work on the product itself: tooling, geometry, freedom-to-operate. Not on listings or ad spend.
What if the Sprint says don’t proceed?
One of the four outcomes is “don’t proceed”, and another is “fix your account health first”. Either way, you pay £1,250 + VAT and avoid a £6,000+ programme that wouldn’t have worked. The honest answer is the deliverable.
Who is the engagement contracted with?
Primed.Design is the trading name; the contracting entity is Cast Iron CAD Ltd, Companies House 07353071.
How long does a full engagement take?
One to two weeks for the Edge Sprint. Typically three to six weeks for the Design Phase once scope is locked. The Manufacture Phase is opt-in after that and runs to your category’s lead times.
Do you sign NDAs before the Sprint?
Yes, on request. The Sprint deliverable is operator-confidential by default; anonymised excerpts only ever appear in Field Notes with explicit consent.
What categories do you work in?
Home & kitchen, garden, pet, sports & outdoors, baby. We avoid regulated categories (food, supplements, electronics requiring CE/FCC unless the operator already holds them).
Section 08 · The practice

An engineering practice. For the operator.

Primed.Design is the trading name; the contracting entity is Cast Iron CAD Ltd. The first stages of Cast Iron CAD’s engineering process, packaged as a 1–2 week paid diagnostic. The hand-off to Cast Iron CAD happens when the answer is “yes, proceed.” When the answer is no, the operator pays £1,250 and avoids a £6,000+ programme that wouldn’t have worked.

Dave Lock runs the practice: 40+ product development projects across consumer, hardware and industrial categories, and a seat on the University of Brighton Industrial Advisory Board.

Dave Lock
Section 09 · Commission

Own a product the factory can’t sell to anyone else.

Three sprints per quarter. Next window Q3 2026. £1,250 + VAT, paid at booking.

Book an Edge Sprint →