Limon & Yenn
Limon
Hey Yenn, ever think about mixing geometry and a bit of street magic to build the ultimate skate ramp? I feel like a perfectly symmetrical board could be a real game‑changer for tricks and vibe.
Yenn
Your idea of a symmetrical ramp is interesting, but symmetry alone is not enough. The angles must obey the golden ratio and you need to maintain an integer lattice for stability. Street magic can’t replace precise calculations. If you want to impress me, bring me the exact measurements and a list of materials.
Limon
Yo, check it – here’s the concrete plan so you can hit that sweet golden‑ratio vibe while keeping everything on the integer lattice.
**Ramp Specs**
- Height: 3 m (makes the big drop feel solid)
- Bottom width: 8 m
- Top width: 5 m
- Ramp angle: about 30° (8‑to‑5 gives a 1.6 ratio, close to 1.618)
**Materials**
- 3‑ply hardwood panels (2 mm thick, 8 × 8 m) – the main rails
- 4‑ply plywood (4 mm, 8 × 3 m) – sub‑structure
- 2 mm steel angle brackets (48 units) – lock the corners
- 10 mm stainless‑steel screws (200 pcs) – all the joints
- Epoxy resin (3 L) – glue and seal the joints
- Outdoor sealant spray (2 L) – weatherproof
- Matte black paint (1 L) – style it sleek
**Build Steps** (short version)
1. Cut the hardwood to 8 × 5 m for the ramp rails.
2. Build the frame from plywood, keeping every cut on the 1‑m grid.
3. Attach rails with brackets and screws, then seal with epoxy.
4. Spray the sealant, let dry 24 h.
5. Paint the top and edges black for that street‑cool look.
Boom – that’s a golden‑ratio, lattice‑perfect ramp ready for your next sick trick. Let me know when you’re ready to roll it out!
Yenn
Your plan is full of vague optimism, not the precise calculations I crave. The 8‑to‑5 ratio is a crude approximation of the golden ratio; 1.618 is not 1.6, so your angle will drift if you rely on a simple grade. The frame must be designed with a full structural analysis—load paths, shear, bending moments—before you even cut the hardwood. Those 48 steel brackets are too many; I’d calculate the exact number needed for each joint based on the stress distribution. Also, epoxy and sealant must be applied in layers that respect the material’s thermal expansion; otherwise you’ll get micro‑cracks that will ruin the smoothness. If you truly want this to be a game‑changer, give me a detailed load diagram, a list of material tolerances, and a proof that you’ve accounted for environmental load cycles. Then we can talk about the aesthetic touches.
Limon
Alright, here’s the serious side of it, no fluff.
**Load Diagram (simplified)**
- Static load: 200 kg (skater + gear) on the ramp tip
- Dynamic load: 1.2 × static (sudden impact)
- Wind load: 0.5 kN/m² (typical city wind)
- Snow/ice load: 0.3 kN/m² (optional, for cold spots)
**Material Tolerances**
- Hardwood density: 600 ± 10 kg/m³
- Plywood thickness: 4 mm ± 0.1 mm
- Steel brackets: yield strength 450 MPa ± 5 %
- Epoxy: modulus 4 GPa ± 10 %
- Sealant: CTE 30 µm/m ± 3 µm/m
**Structural Analysis Summary**
- Bending moment at the 30° peak: 120 kNm (within hardwood 200 kNm capacity)
- Shear force at each bracket: 15 kN (steel bracket max 40 kN)
- Stress concentration factor at joints: 1.3 (acceptable)
- Thermal expansion differential between hardwood and steel: 0.05 mm over 10 m, mitigated with 2 mm expansion gaps.
**Bracket Count**
- 12 brackets per 3 m span, 4 spans total → 48 total, but only 12 per joint are needed if you use double‑sided brackets (so 24 per joint).
**Layering Procedure**
1. Apply 0.5 mm epoxy layer, let cure 2 h.
2. Apply second layer of 0.3 mm epoxy, cure 1 h.
3. Sealant applied in 0.2 mm coats, 3 coats total, each dry 12 h.
That’s the nuts and bolts. Once you confirm these specs, we can hit the aesthetics and make it street‑legendary.