Setting out
Equal centres along a member
- where
- pitch (mm)
- length (mm)
- end margin (mm)
- points
- first position (mm)
- last position (mm)
Explain this equation
Positions a set number of points evenly along a length, keeping the same margin at each end. Use it for fixings, holes, brackets or setting-out marks.
L is the overall length and m the end margin, both in millimetres. n is the number of points. p is the pitch between neighbouring points. x1 and xn are the first and last positions, measured from the start.
Taking a margin off each end leaves L − 2m. n points create n − 1 equal intervals, so the pitch is that length divided by n − 1. The first point sits at m and the last at L − m.
1000 mm with 50 mm margins and 6 points gives a 180 mm pitch, at 50, 230, 410, 590, 770 and 950 mm.
Watch out: these are centre positions, not clear gaps. Check minimum edge distances for fixings.
Find positions with equal end margins and a chosen number of points.
Enter your values to see the result.
Good to know
Point positions, not clear gaps. For fixing layouts use the approved edge distances and maximum spacing.
Sources
- Geometry / arithmetic
This is a calculation aid, not a structural design or compliance certificate. Every default is an example, not a specification for your project.