Measurements

From TheBestCaseScenario

There's an old axiom: Measure twice, cut once. You can never be too careful when it comes to measuring especially when parts are bent, not rigid (enough) or it doesn't have a clear measuring "edge". Here are some tips:

• Use only one measuring system for your project, metric or imperial.
  • Conversions exist, but use them only when necessary
• All items have a "thickness" that needs to be taken into account
  • Only measure perpendicular from a surface
  • Measure from corners
  • Keep your measuring datums consistent
• Not everything fits exactly
  • You will require "space" between items (in planning)
  • Using floating elements or slightly oversize holes can help reduce problems
  • Back drilling or match drilling will help eliminate mismatched holes
  • Printed or supplied measurements for an item are not always represented exactly on a part (Don't count on three 70mm fans place end to end to equal 210.0mm)
  • Watch for tolerance stacking
• Moving parts can be tricky
  • Moving parts often have a bit of "play" in them, if not they're more costly
• Compare planned measurements to actual
  • Use things that about the same size to see if a layout or arrangement will work the way you planned
• Sheet metal bends always have a radius to them
  • Anything placed close to the bend must have relief built in to it