Shuttle motion is reciprocating translation produced here by an ideal in-line slider-crank. Crank radius sets half the stroke, while a constant-length connecting rod closes between the rotating crankpin and guided shuttle.
Shuttle Motion Ideal Slider-Crank Reference
Explore ideal shuttle motion with a connected crank, constant-length rod and guided translating block.
Equation Used
- The crank rotates at constant selected speed.
- The guide passes through the crankshaft centerline.
- The connecting rod and crank are rigid and clearance-free.
- Loads, acceleration forces, torque, balance, friction, wear and ratings are excluded.
Mean speed is total shuttle travel per crank revolution divided by revolution time, not instantaneous speed.
Closed crank, rod and shuttle chain
The animation keeps the crankpin on a circle of selected radius, the connecting rod at selected constant length and the shuttle on a horizontal guide. The exact finite-rod geometry is used for every displayed phase.
What the calculator determines
Select crank radius, crank speed and connecting-rod ratio. The calculator reports stroke, ideal cycle rate, rod length and mean shuttle speed.
Ideal slider-crank reference
Stroke = 2r; cycles/min = N; rod length L = Rr; mean speed = 4rN/60,000 when r is entered in millimetres.
Selected-input arithmetic
For r = 50 mm, N = 120 rpm and R = 4, stroke is 100 mm, rod length is 200 mm and mean speed is 0.4 m/s.
Kinematic reference only
The calculation assumes an in-line rigid slider-crank at constant crank speed. It excludes offset guides, clearance, flexibility, acceleration forces, torque, friction, wear, balance, duty cycle and product suitability.
Questions
Is mean speed the instantaneous shuttle speed?
No. It is total travel per revolution divided by revolution time.
Does rod ratio change stroke?
No. In an in-line slider-crank, stroke remains twice crank radius; rod ratio changes the within-cycle position and acceleration relationship.
Primary and authoritative references
- NASA piston displacement geometry for the crank-slider formula — government technical report identifying the standard crank-slider geometry and piston-displacement relation.
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