DIGITAL MACHINEDESIGN DESK / DFM-03

Thin walls & material behavior

Review the whole wall: height, thickness, support and material condition.

DESIGN INTENTDimension wall height and thickness together.
01Tall, slender section
Section of a 30 mm high, 1 mm thick wall rooted in a base. Height H is measured above the base and thickness t across the wall.

H = 30 mm / t = 1 mm

02Shorter, thicker section
Same-scale section of a 10 mm high, 2 mm thick wall rooted in a base. Both height and thickness are dimensioned.

H = 10 mm / t = 2 mm

WORKED EXAMPLE / mm

Geometry ratio = unsupported height / thickness

30 / 1 = 30 | 10 / 2 = 5
03Support the free span

A rib or thicker root can help support a wall. Preserve clearance and mass targets; check loads, fatigue and stress concentrations.

CAD: shorten spans or add a permitted rib.

04Provide a stable grip

Thin features can move under clamp force and spring back when released. A supported gripping area helps the workholding plan.

CAD: leave accessible support and grip faces.

05Avoid needless one-sided cuts

Residual stress and asymmetric removal can move the part. Review stock condition and the roughing/finishing sequence with the shop.

CAD: remove only the material function needs.

06Specify the material state

Alloy/temper and polymer grade matter. Temperature, moisture and stress relaxation can change dimensions after machining.

CAD: define grade and measurement condition.

WHAT THIS DOES NOT PROVE

H/t describes slenderness. It is not a stiffness calculation, a vibration prediction or a universal pass/fail limit.

BEFORE RELEASE Protect fit, loads, sealing and required material sections when changing geometry.
  • Dimension height and thickness together.
  • Show where supports or ribs are permitted.
  • Identify critical free-state dimensions.
  • Specify alloy, temper/hardness or polymer grade.
  • Review stock stress and asymmetric removal.
  • Agree measurement temperature and conditioning when relevant.