Question: An aerospace company
asked for ZERO's help in creating a relief pattern on the surface of a
ceramic plate. The pattern of evenly spaced bumps resembles an inverted
golf ball skin.
Most manufacturers
would turn to machining to produce this type of pattern, but the
high-tech ceramic plates proved too brittle for conventional CNC
machining processes.
The company
already had created its own templates and tried to manually blast the
plates to remove a precise amount of material while leaving the raised
bumps, but even the most experienced blast operators produced
inconsistent results.
The customer
needed to process fewer than 100 parts per year - one of the lowest
automation production requirements we've ever seen. Each plate was
valued at several thousand dollars, so the customer wanted to limit
rejects to as few parts as possible.
One
blast equipment manufacturer submitted a proposal that included an
indexing turntable and sophisticated computer controls to vary the
speed of the blast gun as it traversed the part. To get a consistent
depth of "machining" with this process, the nozzle must dwell longer at
the outer edge of the spinning ceramic plate, then progressively
increase speed (to decrease the dwell) as it nears the center.
The
customer had a few concerns about this proposal. The system was
expensive, and with so few parts per year to process, this
purpose-built machine would sit idle most of the time. But more
important, the customer feared the sophisticated, variable-speed nozzle
oscillator would not create perfect parts.
Solution: When is a circle not a circle?
This
customer needed to uniformly blast the flat surface of a disc - not the
edge. ZERO treated the disc as if it were a square, which changes the
very nature of the problem. So, how do you deliver consistent blast
coverage to a flat surface?
With the
system ZERO proposed, a motorized work car moves slowly through the
cabinet, while two automatic guns, mounted on an oscillating arm,
thoroughly and consistently blast a square area slightly larger than
the actual part. The overspray falls harmlessly through the perforated
surface of the work car.
Instead of
an indexing turntable with sophisticated computer controllers, ZERO
used a fixed-speed work car and a simple oscillating arm - components
readily available from our "Options-Plus" program. (The Options Plus
program allows ZERO to adapt custom-engineered components from one
system and apply them to another, similar application. By not starting
with a blank CAD screen each time, ZERO's engineers can save money,
reduce delivery time, and still produce a proven system.)
Sample
processing quickly demonstrated that the selected components would
work. To make matters even better, ZERO mounted everything in a
standard BNP 220 suction blast cabinet - with gloves, a manual blast
gun, and view window. When not needed to process the ceramic plates,
the cabinet can be used to manually blast a variety of parts, just like
the customer's other ZERO cabinets.
This
creative use of existing technologies saved the customer a bundle of
money and delivered a versatile cabinet with automated and manual
options.
Got a question about peening, cleaning, or sample processing? ZERO can help. Call 636 239-8130 or submit a request online.
