This partial calculator assumes one handled item per equally spaced pocket per revolution and converts selected throughput, pocket count and pitch diameter into wheel speed, angular speed and pitch-circle speed. It does not predict dwell, capture, release, product stability or line capacity.
Star Wheel - Selected Pitch-Kinematics Ledger
Explore selected one-item-per-pocket throughput and pitch-circle kinematics.
Equation Used
- One handled item is assumed per pocket per revolution.
- Every selected pocket is assumed occupied for the throughput identity.
- Pitch diameter is an entered geometric reference.
- The speed reference is entered and is not a validated limit.
- Handling dynamics, product geometry, drive loads and safety are excluded.
The secondary figure shows equally spaced pitch locations, not designed pocket geometry or a validated guide path.
Selected pitch-kinematics ledger
Under the explicit one-item-per-pocket-per-revolution assumption, wheel speed is Q/Np. Angular speed is 2 pi n/60 and pitch-circle speed is omega D/2. The entered speed limit is only an arithmetic comparison reference.
What the calculator determines
Use it to inspect selected rotational kinematics and compare pitch-circle speed with an entered reference. Do not use it to rate a star wheel or packaging line.
Selected relationships
n=Q/Np; omega=2 pi n/60; v=omega D/2; entered-reference use=100 v/v_ref.
Selected-input example
At Q=250 items/min, Np=10, D=320 mm and entered reference speed 1.2 m/s, wheel speed is 25 rpm, angular speed is about 2.618 rad/s, pitch-circle speed is about 0.419 m/s and the arithmetic reference use is about 34.9%.
Not a handling-performance model
Pocket shape, product geometry, clearances, guide rails, acceleration, dwell, entry and exit timing, slip, collisions, drive torque, strength, hygiene and safety are excluded.
Questions
Does Q/Np always give operating speed?
Only under the stated one-item-per-pocket-per-revolution and fully occupied assumptions.
Is the entered speed reference a validated limit?
No. It is a user-entered comparison value.
Does the animation prove capture and release?
No. It shows only equally spaced pitch positions.
References & Further Reading
- Wikipedia contributors. Star wheel. Wikipedia
Building or designing a mechanism like this?
Explore the precision-engineered motion control hardware used by mechanical engineers, makers, and product designers.
