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Ridgebotics

Elevator

Guide 3

Lifts against gravity the whole way, then slams into a hard stop. Shows steady lift force and holding current, then the tension spike at the stop without a soft limit.

Where the elevator's load goes

Example inputs; the calculator updates these with yours. Imperial first, metric in parentheses.

carriageHits the stop: 613 lbfJam spike: 613.8 lbf(2,730 N) with no soft limitStalled at 40 A: 204 lbf(909 N) rigging tensionJust holding: 24 lbf(108 N) · 6.3 A per motorLoad: 5.5 kg effective(carriage + ½ of stage)Spool hex: 175 lbf per corner(780 N)
appliedcalculatedwatchfailure point

Example inputs from the calculator defaults. Losses ignored.

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Hard stops spike rigging tension well past steady lift

  • Inputs
  • Joint
  • Calc
  • Check
  • Motor type and quantity
  • Current limit

Motor

  • Motor torque at limit and stall
  • Free speed
  • Calc
  • Gearbox ratio
  • Gearbox model

Gearbox

  • Torque per stage vs rating
  • Weakest stage
  • Check
  • Drum diameter or pulley teeth
  • Material

Spool or pulley

  • Bore corner force
  • Pass or fail
  • Check
  • Belt, chain, or rope
  • Cascade or continuous, and stages

Rigging

  • Rigging tension
  • Pass or fail
  • Check
  • Carriage and piece mass
  • Stage masses

Carriage

  • Lift force at stall
  • Travel speed
  • Calc
  • Shock factor at the hard stop
  • Soft limit, yes or no

Hard stop

  • Peak tension at the hard stop
  • Holding current at height
  • Check

What it teaches

Steady-state math says it is fine. The hard stop is where it breaks, and soft limits are a mechanical protection.

Session hook

Run the carriage into the stop at full and half speed and watch the current trace. Repeat with soft limits on.

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