Stackrange

A one-dimensional interval notebook

Add up
the limits.

Enter nominal dimensions and their lower and upper deviations. Follow every added or subtracted contributor to an exact worst-case interval.

Asymmetric deviations · Exact unit changes · Local reports

THE ENTERED GAP

100 − 60 − 39 = 1 mm
0.5 mm1.5 mm
Both endpoints retained.

01 / Define the stack

One direction.
Separate contributors.

A lower deviation is subtracted from its nominal size; an upper deviation is added. Enter both as nonnegative magnitudes.

Optional entered acceptable interval

Enter both bounds or leave both blank. Signed bounds are allowed. Equality at either boundary counts as contained.

1–30 rows; up to 12 decimal places. Each nominal/deviation ≤ 1,000,000 mm equivalent; physical minimum ≥ 0. Criterion endpoints within ±60,000,000 mm. Software bounds and model limits.

01

Build each interval.

A 70 mm nominal with lower deviation 1 and upper deviation 2 spans 69–72 mm.

02

Reverse a subtraction.

Subtracting that same interval contributes−72 to−69 mm. Both endpoints change roles.

03

Read the envelope.

Add signed lower endpoints for the minimum and signed upper endpoints for the maximum.

Keep the closure assumption visible.

You supply the one-dimensional add/subtract relationship. Stackrange does not establish whether a physical assembly follows it, or how often its limits occur.

Work through the housing / insert / spacer example →