Brief
What
is the Product?
The
product is a desktop computer controlled drill that drills holes in printed circuit boards (PCBs) or any similar sheet material. The drill comes with software that interprets HPGL (Hewlett Packard Graphics Language) files that are generated in a CAD package and sent to the drill via the interfacing software.
Design Intent Statement
"To
design a computer controlled printed circuit board drill that interfaces to the parallel port of any PC compatible and is simple to use, for a direct cost of less than £80"
What
makes the Drill Different to Existing Products?
The
drill's unique selling point is its low cost. Existing CNC solutions are very expensive, and appear to be treated by vendors as a specialist technology, whereas the fundamentals are quite straightforward.
The drill can achieve its low cost by:
· making the software perform most of the work, and keeping on-board electronics to a minimum
· careful design to include that which will only add value to the machine from the customer's perspective
· incorporating DFM and DFA in the design process
· using low-cost stepper motors in open-loop control
· using standard bought-in components wherever possible
· using identical X and Y drive modules for cost and assembly effectiveness
· incorporating design features only to meet customer requirements, manufacturing and assembly considerations
Printed
Circuit Board Fabrication
There
are several types of substrates available for prototyping such as stripboard, veroboard TM, wire-wrap, etc. but all of them come under pressure when the hole and component count rises above a few dozen components. Layout becomes very difficult, confusing and the chances of connection error are high. That is when printed circuit methods become beneficial. The low cost of electronic circuit computer aided design (ECAD), and the proliferation of PCs makes design with computer an accessible option. The 'traditional' design process for producing a prototype printed circuit board is shown in figure 1.1
Figure 1.1 - Typical PCB Prototyping Construction
Project Home
