Please enable JavaScript.
Coggle requires JavaScript to display documents.
L06 Engineering Design - Coggle Diagram
L06 Engineering Design
Clearance Fit and Interference Fit
In clearance fit,
there would still be an allowance for two parts to move, such as in a door hinge.
.
In interference fit,
it would be difficult to move (or remove) the two interfacing parts. Usually, a lot of force is needed to remove the two parts. Examples are shafts that are fitted through bearings, so that the shaft does not slip.
Dimensions in drawing
9 types of dimensioning
Parallel Dimensioning, Superimposed Running Dimensioning, Chain Dimensioning, Combined Dimensioning, Dimensioning Small Featured, Dimensioning of Multiple Features, Dimensioning of Radius, Dimensioning of Cicrle Arc and hole, Dimensioning Angles
Tolerances
Bilateral Tolerance
: allowed to vary in two directions from the specified dimension. Both directions need not vary by the same amount.
Unilateral Tolerance
: allowed to vary in only one direction
Limit Tolerance
: the upper and lower limits of the dimension are specified
Formula for Calculating Tolerance:
Tolerance = Upper limit – Lower Limit
Rules of dimensioning
Dimensions should not be duplicated, i.e. same dimension should not be repeated on different views, or the same information need not be given in two different ways
Avoid dimensioning to hidden lines and features
Dimension lines, extension lines and object outlines should not cross or overlap
Assembly Modelling
Creating joints, joint movement provides degrees of freedom.
Types of joint
Rigid, Revolute, Slider, Cylindrical, Pin Slot, Planar, Ball