MY SIMULATOR

English Apple Press Simulator

Turn the press. Discover the harvest.

INTERACTIVE 3D

Virtual demonstration only — not instructions for building or operating a real press. Values are model values.

Apples 12 kg

Pressure 150 kPa

Juice0.0 L

Lab & science

Drag to orbit, wheel / pinch to zoom, tap a part to inspect it. Space = start / pause, R = reset, ←→ = pressure.

Setup

Grind fineness (finer mash gives more juice but drains more slowly)

Thread friction μ (greased < dry wood-on-iron)

Model-time speed

Camera

Graphics (High on every device; Low = fewer leaves, 1x pixel ratio)

Live readout (model values)

Missions

Mission 5: with the current friction, what axial force (kN) does a 250 N push at the lever end give?

The science

What you see

A wooden-framed screw press squeezes crushed apples (pomace) in a slatted basket. A lever turns an iron screw; every turn lowers the plate by one lead (30 mm). The juice runs through the slats, along the dished tray and out of the spout into the jug.

Equations

Plate pressure      P = F / A          A = pi R^2 = 0.102 m^2
Screw force         F = 2 pi eta T / p  (p = lead 0.030 m)
Torque for F        T = F [ (dm/2) tan(lambda+phi) + mu_c r_c ]
  lambda = atan(p / pi dm),  phi = atan(mu)
Hand force          F_h = T / L_lever   (L = 1.0 m)
Juice volume        V_inf = eta_x X m / rho_j
  eta_x = eta_max (1 - exp(-P_max / P0))
Drainage (Darcy-like) dV/dt = (V_inf - V) / tau
  tau = tau0 (h/0.2)^2 k_f exp(P / P_k)
Cake height         h = [ V_air0 exp(-P/Pa) + (m - rho_j V)/rho_s ] / A

Symbols: m apple mass (kg), X juice-bearing mass fraction (0.84), rho_j 1050 kg/m³, eta_x extraction efficiency, mu thread friction, mu_c collar friction 0.12.

Assumptions & honest simplifications

Square thread, one lumped friction coefficient; collar friction included; wood-frame flex, lever whip and crushing of the screw are ignored.
The pressure ramps at 6 kPa per model-second and the screw is turned so that the plate follows the cake height. Juice cannot flow back when pressure is reduced (P_max governs yield).
Extraction curve, drainage time and air-void constants are illustrative model values chosen to behave like a farm press, not measurements of one press or one apple variety.
Scene is artistic; the barn, wall and trees are decoration, not a real location.
[assumption] Pressures above about 250 kPa are not reachable by hand at this lever length (hand force passes 440 N).

Independent numerical checks

The same checks run in node: node check.js (second integrator RK4, wedge-force derivation, mass balance).

Sources

Textbook power-screw mechanics (Shigley-type machine design) and food-process-engineering treatments of pressing/consolidation; cider-press museum interpretation. Constants are model values [verify against a source before real use]. Not affiliated with any press maker.

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