CNCCMV2/Structure/Techniques

=Point Marking with Datum Points and Edges=


 * Datum points and edges are points and edges of the workpiece that you measure from.


 * In most cases, 2 datum edges will be used. How to measure using 2 datum edges is shown in the diagram below.




 * When marking to drill, center punch the points so that that drill bit centers into the desired position during the operation.

=Match Drilling=


 * Match drilling is the process of drilling through multiple components at the same time so that the final assembly is aligned perfectly.


 * Match drilling works effectively with templates. For instance, a template can be placed on top of a component, then match-drilled; the template can be reused for other components which require the same hole pattern. This template multi-usage is useful when multiple components need excellent alignment but are too large or irregularly-shaped to be match drilled together.


 * A process similar to match drilling is to drill a workpiece before it is cut apart to separate components. For example, a 100cm metal rod can be drilled through, then cut in half so that the holes of the two 50cm metal rods align perfectly together.


 * Match drilled components mounted with a C-clamp are shown below. Those bronze rod-like things are called clecos; clecos hold the components aligned together during drilling (extra secure than just with the initial clamps), especially useful for large multi-hole operations.



=Mounting=


 * Rotating components such as drill bits and parts to be lathed require the use of a chuck.


 * A lathe chuck is shown below.




 * A drill chuck is shown below.




 * Stationary components such as those to be operated on by a drill press require the use of clamps, vises.


 * Drill press clamp below.




 * Drill press vise below.