A screw stamping press converts rotation of a weighted handle into vertical screw travel through a fixed nut. The animation shows this motion; the separate calculator compares rotational energy at two selected speeds for unchanged inertia. It does not calculate stamping capacity.
Rotational Speed and Kinetic-Energy Comparison
Compare selected flywheel speed drop and relative kinetic-energy change for unchanged inertia.
Equation Used
- Flywheel inertia is unchanged between the two selected speeds.
- The entered speed drop is a selected comparison, not a predicted cycle result.
- The displayed screw advance is normalized and does not represent a machine dimension.
- Absolute energy, force, stroke, losses, tooling and material forming are excluded.
The connected press visual uses normalized illustrative screw advance, not a calculated stroke.
Weighted handle and fixed nut
The weighted cross-handle and screw turn together. The fixed nut in the C-shaped frame converts that rotation into vertical travel of the pressing head; reverse rotation raises the head. Brown movement 105 illustrates this screw-press arrangement.
The illustration uses an arbitrary screw lead and stroke, with a gap above the stock at the lowest position. It explains the motion without simulating impact or material deformation. The selected calculator speeds do not control the hand-operated stroke.
What the calculator determines
Select a reference flywheel speed and a percentage speed drop. Outputs are selected post-drop speed, retained speed fraction, retained kinetic-energy fraction and kinetic-energy reduction, assuming the same inertia before and after.
No flywheel inertia, absolute energy, screw lead, torque, force, stroke, die load, material work or machine rating is calculated.
Relative kinetic-energy identity
With E = Iω²/2 and unchanged I, E₂/E₁ = (ω₂/ω₁)² = (N₂/N₁)². Here N₂ = N₁(1−d/100), retained speed is 100N₂/N₁, and kinetic-energy reduction is 100[1−(N₂/N₁)²].
Selected-input arithmetic
For N₁ = 400 rpm and d = 10%, N₂ = 360 rpm, retained speed is 90%, retained kinetic-energy fraction is 81%, and the relative reduction is 19%.
What the comparison can tell you
Absolute flywheel energy requires inertia; press motion requires screw lead and kinematics; stamping requires force–displacement work, machine stiffness, tooling, stock and losses. None are entered here.
A percentage energy reduction alone does not tell you the energy delivered to the workpiece. Use machine-specific data for setup or diagnosis.
Questions
Why does energy scale with speed squared?
For fixed inertia, rotational kinetic energy is Iω²/2.
Is the 19% example energy delivered to a blank?
No. It is only flywheel kinetic-energy reduction relative to the selected initial speed.
Does the animation show the selected stroke?
No. Its advance is normalized because lead and stroke are absent.
Can this size or operate a press?
No.
References & Further Reading
Henry T. Brown, Five Hundred and Seven Mechanical Movements, movement 105: screw stamping press with weighted cross-handle.
- Wikipedia contributors. Screw press. Wikipedia
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