We need two original shark species, each in two production sizes:
Species Sizes Notes
Great White Shark (Carcharodon carcharias)1 oz, 2 oz The universal shark icon; maximum recognition and consumer appeal
Great Hammerhead (Sphyrna mokarran)1 oz, 2 ozIconic distinctive silhouette; the "T-shaped" head reads instantly even at small scale
The two sizes per species are not just scaled versions. The 1 oz model can be a slightly stylized/proportioned version, while the 2 oz can be a more anatomically realistic version of the same species — your choice, but the two sizes should clearly be the same "personality" of shark.
Lead density: 11.34 g/cm³.
1 oz model: 28.35 g target → internal solid volume ≈ 2.50 cm³ (±3%)
2 oz model: 56.70 g target → internal solid volume ≈ 5.00 cm³ (±3%)
The cavity will be machined into a Do-It Molds Aluminum Blank — a standard 3" × 5" × 1.5" two-piece aluminum block, milled by a CNC shop using your CAD as the toolpath source. This means:
Single planar parting line. The shark must split cleanly along one flat plane (typically the vertical centerline running snout to tail tip). Anything that requires a curved parting surface or a side-pull is rejected.
No undercuts relative to the parting direction (perpendicular to the parting plane). Every surface must release straight away from the parting line.
Draft angles ≥ 1.5° on all faces transverse to the parting plane. Vertical fins, gill slits, eye recesses — all need draft.
Maximum bounding box per cavity: 75 mm long × 35 mm tall × 25 mm wide for the 2 oz; 60 mm × 28 mm × 20 mm for the 1 oz. (These leave room in a 3"×5" Do-It Blank for two cavities + sprue/vent network.)
Minimum wall thickness anywhere in the casting: 4 mm. No thinner fins, tail filaments, or details that would freeze before lead fills.
Smooth concavities — no sharp inside corners below 2 mm radius. Lead pours need flow-friendly geometry.
Each shark needs a way to attach to fishing line. Preferred approach: a recessed cavity for a press-in brass eyelet (Do-It part: #1 Brass Eye)
Aesthetic Direction
Stylized realism, not cartoon. Anglers should recognize the species at a glance. Children-friendly cuteness is not the brand.
Dynamic, predatory pose. Mouth slightly agape is welcome; full open-jaw is not (no mold-friendly way to do that). Slight body curve is welcome.
Surface detail at scale. Gill slits, eye, lateral line, dorsal fin, tail flukes should be visible but not so fine they won't cast cleanly in lead.
Belly slightly flattened so the weight has a stable resting orientation on the bottom and won't roll unpredictably during retrieval.
Deliverables
For each of the four finalized models:
STEP file (.step / .stp) — for CNC toolpath generation
STL file (.stl) — for visualization and verification
Solid native source file (Fusion 360, Rhino 3DM, ZBrush ZTL, or Blender .blend — whichever you used)
Volume-verification screenshot showing the computed solid volume, to confirm we're on weight target
One marketing render per model (PNG, 2000 px wide, transparent background, 3/4 view)
A combined CAD assembly file showing both 1 oz and 2 oz cavities of one species positioned within a 3"×5"×1.5" Do-It Blank, with sprue and vents drawn — for our CNC partner
IP & Ownership (Critical)
This is a work-for-hire engagement. AC Metals will own the copyright in all designs, source files, and renders the moment final payment is made.
You may not post the work to Thingiverse, Cults, GrabCAD, ArtStation, your portfolio, or any public site without written permission. (We will likely grant portfolio rights once SKUs are publicly launched, but we want to control the timing.)
The designs must be original — no derivative work from existing CAD files, including any Thingiverse, GrabCAD, or scanned-figurine sources. By accepting this contract you certify your work is original to you.
Total timeline: 4 weeks from kickoff.
Budget
$500 USD total for the two species / four finalized models, 50% deposit/50% final payment at receipt of final files.
If we're delighted with the result, we'll commission additional species and animals.
Who We're Looking For
3D modeling experience with organic / character / sculptural subject matter (please share at least 2 portfolio examples)
Familiarity with manufacturing constraints for cast metal or molded parts — draft, parting lines, undercuts, sprue/vent design. If you've done designs for jewelry casting, miniatures, fishing lures, or injection-molded toys, you're well-positioned.
Comfortable working in STEP-compatible CAD (Fusion 360, Rhino, SolidWorks, etc.) for the engineered features, even if the sculpting happens in ZBrush or Blender. We need a clean STEP for the CNC shop.
Communicates clearly and meets milestones.
In your proposal, please include:
2–3 portfolio links showing organic/sculptural CAD work
Your software pipeline (e.g., "ZBrush sculpt → Fusion 360 for engineering features → STEP export")
Confirmation that you can hit the volume tolerances and mold-friendly geometry constraints in Section 3
We will provide necessary requested reference materials as needed. Inspo photos of desired shape, existing Do-It Molds product references