# Simplified screw: axial thrust from torque and efficiency
torque = 3 N*m in 0.5..10
lead = 5 mm in 2..12
efficiency = 0.35 in 0.2..0.8 "Assumed overall"
turnRate = 300 rpm in 100..900
thrust := 2 * pi * efficiency * torque / lead [N]
linearSpeed := turnRate * lead [mm/min]
check load budget: thrust >= 500 N
scenario efficient: efficiency = 0.65