Direct Part Marking, refers to permanent marking of a part. using a dot peen system. Many industries demand permanent symbols be affixed to parts, that are not removable.
Part numbers, serial numbers and even shift numbers for traceability of critical parts, are demanded.
The pneumatic dot peen is computer driven and can satisfy these requirements, as well as being easily adaptable to robotics engineering and is very fast in operation.
A small, private, business, with less than 50 employees, had a part to be marked and therefore was looking for direct part marking equipment.
Their basic business, is importing flexible conduit and designing and manufacturing special wiring harness assemblies.
A lot of these assemblies, require special fittings, that are manufactured, in house, on CNC machine tools.
All of these fittings require direct part marking. This was being accomplished, by using a simple, roll type date stamp, that required daily digit changes and was limited in character selection. Parts ranged in size, from 0.59 in. (15mm) diameter x 0.59in.(15mm) long, to 6.0in (152.4mm) diameter x 4.0in.(100mm) long. Material was aluminum, stainless steel, brass or carbon steel.
Shapes could be round, square, hexagonal or any shape.
It was essential that the marking be visible, after plating and desirable to be able to mark the company logo, on the part.
The owner of the company, thought that laser marking, was a possible solution and we were hired to find the ideal method, for this particular customer. Annual production was approx. 50,000 pieces.
The methods applicable, were really only two, namely a laser mark or pneumatic dot peen marking
Cost wise, the laser would be more expensive - maybe by a factor of 4 or 5,but the quality and speed would be first class.
However, the dot matrix technology, enabled us to do almost as much as the laser, but at a much reduced cost.
The unit finally chosen, was as shown in the photo above.-A Telesis Tmp6100/90 complete with a rotary axis, on which multiple small, cylindrical parts, could be simply assembled.
For smaller parts, a simple fixture was constructed, that allowed multiple parts to be assembled on a shaft. The shaft was then gripped in the chuck and the direct part marking unit was then programmed for multiple parts.
Note that on circular parts, the part rotation is timed with the marking head, to minimize character distortion.
Note that with this system, the dot peen is programmed via a computer, so the days of manually changing the type, on a daily basis, are over!
A computer is now dedicated to the workshop and it is much easier to change the code and part numbers.
The system has been installed for almost a year and is performing well.
The total cost of the system was less than $20,000.00 and the consulting hours, ( by the writer) were less than 50.