A Proposal for
Happy Tank
Multi-Mode Mechanical Aquarium Feeder
Happy Tank & the Engineering Validation Engagement
The Narrow Path Sp. z o.o is a Polish-registered product business founded by Jonathan Agudelo, now based in Australia. Happy Tank is the company's flagship product: a fully mechanical, gravity-fed aquarium feeder designed to address overfeeding and food wastage in home aquariums, the most common cause of poor water quality and avoidable fish mortality.
The product is built around three components: a main feeder clip that mounts to the side of the tank, a frozen food defroster and rinser attachment, and a seaweed holder clip. The feeder is purely mechanical with no electronics, designed for tool-less assembly and intuitive use by the aquarium owner. Target retail is USD 24.99 with an annual forecast of approximately 10,000 units, distributed initially through large pet store chains in Australia ahead of broader online and retail channels.
Jonathan has progressed the product through the full concept and validation phase independently. A complete CAD model is in place across the three components, 3D-printed functional prototypes have been built and physically tested, and the retail packaging has been developed with a Chinese packaging supplier and produced as a physical sample. Two design refinements remain open: a magnetic clip mechanism to allow flexible mounting on top or side of the tank, and a flap or blocker to prevent fish entering the feeder body. One component requires a tooling strategy decision, and another requires engineering input to lock the configuration before production-intent design release.
C2W and Shield Works have been engaged to take Happy Tank through the engineering work needed to convert the existing functional concept into a manufacturable, tooled, mass-production-ready consumer product, with Shield Works as the manufacturing base in China. This proposal covers Phase 1 of that program, titled Engineering Validation, operating under the NDA already in place between our teams.
Program Targets
The following reflects the current working assumptions drawn from the brief and the discovery call. Pilot and first production volumes will be reconciled and validated through Phase 1.
| Item | Current working assumption |
|---|---|
| Engineering Prototype Quantity | 3 sets of validated injection-moulded prototypes (or equivalent first-shot tool samples) covering the three components |
| First Mass Production Run | 5,000 units (working assumption, to be reconciled in the Development Roadmap) |
| Annual Forecast Volume | Approximately 10,000 units per year |
| Target Retail Price | USD 24.99 per unit |
| Target Unit Cost | To be validated through the Phase 1 Indicative Quotation |
| Target Markets | Australia primary, large pet store chain distribution, online to follow |
| Timeline | No fixed client timeline; Jonathan expects full funding within approximately one month and is ready to start at that point |
| Funding Status | Self-funded startup, funding round expected within approximately one month |
Six Phase 1 Deliverables
Phase 1, Engineering Validation is the first paid engagement in the Happy Tank development program. The work is engineering-led: an independent engineering review of the existing CAD across the three components, focused engineering treatment of the two open design changes, a dedicated workstream on the injection moulding strategy and tooling feasibility for the feeder body, a DFM, DFA, and DFX engineering assessment across the full product, supplier engineering engagement with indicative pricing, and a Development Roadmap that consolidates the output into a costed phase-by-phase pathway to qualified mass production manufacture.
Duration: approximately 5 working weeks from confirmation.
Phase 1 consists of the following six deliverables.
A working technical session with the Shield Works R&D team, not an introductory call. We walk through the existing CAD across the three components, the functional 3D-printed prototypes, the two open design changes, Jonathan's commercial and retail goals, the proposed two-cavity moulding assumption, and the trade-offs across tooling configuration, materials selection, and consumer assembly, and agree the engineering priorities and workstreams before work begins.
Written, annotated engineering review of the existing STEP files across the main feeder clip, the frozen food defroster and rinser attachment, and the seaweed holder clip, with specific commentary on each component and a ranked list of recommended design directions. The two open design changes are addressed directly within this deliverable: a magnetic clip mechanism allowing both top and side mounting with reliable retention under normal use, and a flap or blocker concept preventing fish from entering the feeder body. Output: annotated engineering commentary, design direction for the two open changes, and a consolidated revisions schedule carried into Phase 2 for execution.
Dedicated engineering workstream on the central technical question on the product. Jonathan's working assumption is that the feeder body can be produced in a single piece using a two-cavity injection mould with sliders. The internal geometry, the cross-bar pivot, and the curved scoop end at the base require this assumption to be validated under proper engineering review before any tooling commitment is made. The workstream addresses cavitation strategy, slider and side-action requirements, draft angle and parting line review, undercut treatment, material selection for clear injection moulding across the components (typically SAN, PMMA, or polycarbonate depending on optical and durability priorities), and the tooling configuration options across the three components with indicative tooling cost bands. Output: documented engineering position with the recommended tooling direction and indicative cost ranges for Phase 2 confirmation.
Written assessment covering DFM and DFA across the three components and the consumer-side assembly architecture, the tooling strategy carried over from the workstream in Deliverable 3, materials and finishes direction, tolerancing across the moulded components, the magnetic mounting interface, the consumer assembly mechanics between the feeder body and the side or top mount, and a structured risk register with mitigations. Preliminary at this stage against engineering analysis and supplier data; full DFM execution, drawing release, and supplier qualification testing sit in Phase 2.
Qualified supplier shortlist drawn from our Shield Works injection moulding supply chain and wider network, with first-round engineering engagement to confirm capability and capacity across the three components. Indicative unit pricing at the 5,000 first-run and 10,000 annual volume tiers, benchmarked across the shortlisted suppliers. Accuracy is subject to the defined level of readiness for manufacture; final unit costs are locked against specific supplier quotes as the Phase 2 development phases progress.
The 25 to 35 page consolidating document that carries the Phase 1 engineering output forward into Phase 2 and through to qualified mass production manufacture. This is the full Route to Market Plan for Happy Tank.
- Phase timelines and phase management costs across the full development program.
- Shield Works resource allocations and core deliverables across sampling, development, design execution, prototyping, pilot run manufacture, mass production, and scaled production.
- Consolidated written output of the Phase 1 engineering work, including the CAD and design review, the two design change directions, the injection moulding strategy workstream output, and the DFX assessment.
- Component-level bill of materials with material specifications and qualified supplier direction.
- Mechanical engineering and DFM plan across all three components.
- Tooling strategy and indicative tooling investment budget.
- Prototyping and iteration plan with validation gates.
- Integration plan with the existing packaging direction developed by Jonathan's current packaging supplier.
- Pilot run manufacture plan with QC gating criteria.
- Mass production pathway and scaled production goals.
- Risk register with mitigations and owner assignments.
Note: Phase 1 is the first phase of the Happy Tank development program. Phase 2 and subsequent development, tooling, prototyping, and production work is scoped and costed within the Development Roadmap for Jonathan's approval before any execution begins.
What Sits Outside Phase 1
The Phase 1 fee covers all six deliverables in Section 3, including engineering work, CAD and design review, the two design change directions, the injection moulding strategy workstream, DFX assessment, supplier engagement, indicative quotation, and the Development Roadmap. The following are excluded and would be scoped and costed within the Development Roadmap itself or handled directly by Jonathan.
once a supplier set is confirmed and production begins, C2W and Shield Works operate as Happy Tank's manufacturing partner. Jonathan receives a single unit cost for each unit that covers goods, assembly, quality control, supplier management, packaging integration, and logistics coordination. These are not billed as separate service fees. The Phase 1 Supplier Engineering Shortlist and Indicative Quotation is specifically designed to establish those unit costs with confidence before any production commitment is made.
Phase 1 Payment
| Stage | Fee | Payment Trigger |
|---|---|---|
| Phase 1, Engineering Validation | USD 4,000 | Payable in full on project confirmation |
How We Keep Phase 1 Honest
Why C2W and Shield Works
From Confirmation to Phase 1 Delivery
This proposal is non-binding at this stage and is intended to give Jonathan clarity on cost, structure, and what Phase 1 will actually produce. If you are happy with the direction, we can move to invoicing at your convenience and proceed from there.
Best regards,
Mark Jacobs
CEO, C2W Group / Shield Works
June 2026