My SimulatorEngland / Orchard Crafts

English Apple Press Simulator

Turn the handle. Discover the art of pressing.

Interactive 3D • Somerset

PRESS CONTROLS

Pressing force

Light180 N per handStrong

Juice collected0.0 L

Apples in basket 0 kgSupply 40 kg

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

Lab & science

Drag to orbit, wheel / pinch to zoom, tap a part to inspect it. Space = start / pause, L = load apples, T = turn screw, R = reset, ←→ = force.

Setup

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

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

T-bar arm length from the screw axis (a longer bar = more torque per push)

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, with the current friction and arm length, what axial force (kN) does a 250 N push by each hand 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 / (2 a)     (two hands push a couple, arm a = 0.5 m)
Force slider        P_target = 2 F_h a / (k A)   (F_h = push of each hand)
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.
Basket capacity 20 kg of mash, 2 kg per load; the jug holds 2 L and is poured into the cask when full (cask volume is not drawn). The screw is self-locking, so releasing the handle holds the pressure.
Scene is artistic; the barn, wall and trees are decoration, not a real location.
[assumption] At the default 0.5 m arm, 300 N per hand gives about 170 kPa; a longer bar (Lab panel) reaches higher pressures with the same push.

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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