Free hand sketching in engineering graphics are a very critical part of any engineering project. It may be used at any stage of a project’s life cycle, whether it is the planning, execution or even end phase of the project, it is a way to convey critical information regarding certain aspects of the project.
What is a free hand sketch?
- A free hand sketch is a hand drawn sketch that convey information about the detail of a particular part or section of a project or component
- It aids in eliminating errors on the drawings later on by having a clear understanding about the details that must be drawn
- It is a “step” between the actual part that must be drawn and the completed drawing
The small bench
This is the actual small bench vice that needs to be drawn. The vice could not be removed from the workshop, because it is in daily use. More vices just like this one needs to be manufactured.
Measure and sketch
This is the free hand sketch that was made of the vice in the workshop. Measurements was taken of the vice as it was not a option to remove the vice and take it to the drafting office.
A 3d model was created from the free hand sketch. All geometry for the 3D model was taken from the sketch.
The drawing that was made from the free hand sketch. No dimensions and details has been added to the drawing yet.
Where and when are free hand sketches used?
- Free hand sketches are used during the beginning and early stages of a design when the designer illustrates certain configurations or fits to the draftsman
- Modifications or alterations can be indicated with a free hand sketch during the drafting or even manufacturing phase. Often times modifications are made and the modification is captured with a free hand sketch that is later incorporated into the drawing
- Often times a draftsman would visit the client to measure and make free hand sketches of equipment or components that must be drawn
- A sketch is made of what is required on a drawing
- The component may only be available for a short time, thus a free hand sketch needs to be made to use for the creation of a drawing
Requirements of a free hand sketch
- Free hand sketches should be made proportional. As in the example above, I used each block as a 5mm representation. This helped to keep the sketch of the different parts proportional
- Details should be indicated correctly, inaccurate information will translate to mistakes on the final drawing
- The free hand sketch should have as much detail as possible
- It should include all features that may have an impact on the design of the part/section
- It should be readable by someone else. Sometimes it may happen that someone else will be creating the drawings, so one should make sure that someone else can work from the sketch
- Neat and tidy sketches makes creating the drawings easier
- Complete with all the relevant dimensions. Missing dimensions will cause difficulties when the actual drawings are made.
- Correct and complete. Remember, the sketch is the main information where the drawing is created from, correctness and completeness is vital.
How to draw a free hand sketch
Paper to be used
If possible, use a page with blocks on (as shown above). It will make it easier to draw straight lines, draw in proportion and just the overall neatness of the sketch
If you do not have lined or blocked paper, blank paper can also be used. When using blank paper, draw the lines very faint first and then draw dark over it. It will help to keep sketches neat and with less mistakes
Circles, radii & ellipses
Circles, radii and ellipses are often difficult to draw . Instead of just jumping in and drawing a circle, make small marks on the paper to mark reference points of the circle. Then, just “connect the dots” and it can make a circle or radius look much neater.