Sine Bar Angle Setup
Precision angle setup: the angle from a gauge-block stack on a sine bar (theta = arcsin(H / L)).
Example
You enter
- Solve for angle
- Sine bar length (in: roll-center distance) 5
- Gauge-block stack height (in) 2.5
You get
- Angle 30 deg
- Gauge-block stack 2.5 in
- Bar length (in) 5
Checked against published worked examples from: U.S. Navy, Naval Education and Training Command.
Details, formula, and sources
ScopePrecision angle setup: the angle from a gauge-block stack on a sine bar (theta = arcsin(H / L)), or the stack height for a target angle (H = L x sin(theta)), for any roll-center length (first-principles sine-bar trigonometry).
Formula or tablesin(theta) = H / L, where L is the sine bar length (roll-center distance) and H is the gauge-block stack height; so theta = arcsin(H / L) and H = L * sin(theta).
Source and editionSine bar / sine plate angle setup - the standard precision-angle relation as in Machinery's Handbook (Industrial Press), by name; first-principles trigonometry.
Free accessPure trigonometry, public; the gauge-block grade and surface-plate flatness govern the achievable accuracy.
What governsEstimate. AHJ and licensed professional govern.
API field namessolve_for, bar_length_in, stack_height_in, angle_deg
- Roll-center length L is the center-to-center roll distance (commonly 5 in or 10 in), not the overall bar lengthsine-bar geometry