Ever spend hours crafting a design, only to find a tiny detail missing later? We’ve all been there. That’s why a pre-flight check, or design review checklist, is your best friend. Think of it as a mission control for your drawings, ensuring a smooth launch into manufacturing.
This checklist is your co-pilot, guiding you through key areas to ensure your design meets all specifications. Let’s take a flight through the essential checks for both parts and assemblies:
Drawing Checklist
Part Drawing
- Specify cavity no. location (if applicable)
- Specify date stamp location (if applicable)
- Check draft angles for moulding and casting components
- Complete Drawing Template
- Correct Material
- Correct Title [include product descriptions, etc…]
- Date drawn
- Correct Sheet Scale displayed
- Latest updated details as “drawn by” and “designed by”
- Make sure all drawings are in 3rd angle projection
- Check Revision Block
- Tapped holes shown including tapping detail and tapping depth
- Critical dimensions shown as specified by designer/engineer
- Company logo on at least one visible part in the assembly
- Cavity Numbers and Logo needs to state if detail is to be raised or sunken.
- Correct Material to state its “grade” or “alloy”.
- Revision Block to state past and present info (e.g. what dimension was and what is now).
Assembly Drawing
- Check BOM and ensure numbers matches with BALLON Annotations
- Specify Grease grade, quantity of grease and surface required
- Specify Loctite grade, quantity and location
- Title includes product no. and applicable project numbers
- In BOM include kitting information if it is supplied in pack.
- Packaging details specified
- If a “Newton Metre” or “Torque” requirement is needed, this should be shown on the assembly drawing.
Drafting Checklist
Things to Consider
- All units are assumed to be mm.
- Dimension lines should never cross other dimension lines.
- Dimension lines should avoid crossing extension lines.
- Extension lines may cross each other.
- Longer dimensions should be placed further to the outside. (to avoid crossing).
- Try to avoid long extension lines.
- Dimensions should not be duplicated, or the same information given in two different ways, and no dimensions should be given except those needed to produce or inspect the part.
- Dimensions should be placed in the views where the features dimensioned are shown in true shape. This may require auxiliary views. (i.e. Dimension only to true lengths).
- Notes should always be lettered horizontally on the drawing.
- Make sure drawings are checked.
Tips
- Create dimensions from datum point, like bearing, dowel holes or center line instead of curved surfaces.
- Spreading out views on sheet is cleaner than squeezing in.o Specify Geometric Tolerances on sheet metal and machined parts as required.
- A dimension should be attached to only one view: extension lines should not connect two views.
- Notes should always be lettered horizontally on the drawing.o Avoid dimensioning to hidden lines.
- Avoid a complete chain of detail dimensions; better to omit one.
- Otherwise, add REF (reference) of brackets to one detail dimension, or to the overall dimension. This allows tolerances to determine the omitted dimension.
- Dimension lines should be spaced uniformly throughout the drawing. Approx. 10mm from the object, and 6mm apart.
- Dimension figures should be approximately centred between the arrowheads if possible.o No dimensions unless absolutely necessary.
- No hidden detail unless absolutely necessary.
- Keep number of views (projections) to a minimum.
- Three views are normal, the maximum (6 views) are extremely rare.
- Add centre lines and cross-hairs to holes.
By following this checklist and these pro tips, your designs will be ready to soar! Remember, a little pre-flight prep can save you a lot of time and frustration down the runway. So, fire up your design software and prepare for a successful launch!