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Module07
Title

Machine parts

Synthetic Course: written to test the Site template, from no Professor's material

Worked examples

TopicMachine parts
Title

The volume of a flanged hub

ExampleW07.1
Step1 / 4
Mode
Given
Given

A flanged hub is a flange of diameter 80 mm80\ \text{mm} and thickness 10 mm10\ \text{mm}, with a hub of diameter 40 mm40\ \text{mm} standing on it to an overall height of 30 mm30\ \text{mm}. A bore of diameter 20 mm20\ \text{mm} runs through both, and four bolt holes of diameter 8 mm8\ \text{mm} pass through the flange. Find the volume of the hub.

  • flange ∅80 mm\varnothing 80\ \text{mm}, 10 mm10\ \text{mm} thick
  • hub ∅40 mm\varnothing 40\ \text{mm}, overall height 30 mm30\ \text{mm}
  • bore ∅20 mm\varnothing 20\ \text{mm}, through
  • four bolt holes ∅8 mm\varnothing 8\ \text{mm} through the flange
Scaled
measured off a drawing: overall height 30 mm30\ \text{mm}
Assumed
supplied here, not in the Materials: bolt holes ∅8 mm\varnothing 8\ \text{mm}
Each primitive's volume V=π4d2lV = \frac{\pi}{4} d^2 l, added or taken away
PrimitiveddmmllmmVVmm3\text{mm}^3
Flange8010
Hub4020
Bore2030
Bolt holes, four810
Total

Split it into primitives

The hub is two cylinders that add (the flange, and the hub standing on it) and two kinds of hole that take away (the bore through both, and the bolt holes through the flange). None of them overlaps another, so their volumes add and subtract exactly. The hub stands 30−10=20 mm30 - 10 = 20\ \text{mm} above the flange.
3D part

The flanged hub

The hub of W07.1 as an exact solid: a flange with four bolt holes, a hub, and a bore through both. Turn it to see the holes from below.

Drawing the part…
The part's dimensions, in millimetres
DimensionmmRead as
Ø80stated
10stated
Ø40stated
30scaled off the drawing
Ø20stated
Ø8assumed
60stated