Cray Supercomputers was known for their computing power and unique physical appearance. Industry standard racks were not their style. Five companies were provided budgets to explore new appearances for their last Cray built supercomputer. Cray had several unique requirements. The dress panel had to be light enough that one person could remove it. The size of the racks were non-standard as were their processing boards. Each board had 1,500 pins all inserting at once making insertion force high, even for the low insertion force backplane connectors they specified. Power and cooling requirements were extensively high. Each competing company had to provide several appearance illustrations as well as justify weight, manufacturability and cost. We felt we could win the overall contract as our knowledge of design for manufacturability and understanding of costs were head-and-shoulders above our competition.
Manufacturing of the system rack and cardcages had been problematic. Historically, each rack and cardcage were built using enormous machined fixtures at great expense and that parts were fitted and match drilled before assembly. Even with these heroics, pins would get bent when inserting their massive and extraordinarily expensive processor boards into the cardcages.
Our team one the final contract. The dress panel was produced using pressure forming. For rigidity it needed to be produced as a twin sheet panel (2 panels formed simultaneously in one machine that bond to each other). While there are twin sheet forming machines on the West coast, none were large enough to produce this panel. One panel’s geometry gave it vertical rigidity and a second internal panel provided horizontal rigidity resulting in a stiff panel. We needed to devise a new manufacturing process where 2 panels could be separately formed and then accurately bonded together after the two separate forming operations. Our resulting process yielded a part that was so good no one could have predicted the tolerances would have been that accurate. This panel won industry awards that year.
The sheet metal custom rack mount frame needed to be addressed. We came up with a new method of manufacturing and assembly. Historically it would take 3 people nearly a day with drill motors match drilling parts clamped into enormous and expensive fixtures to produce an acceptable frame and cardcage. Our new design approach utilized both part geometry that would minimize tolerance stack-ups from both punching and forming. In fact it was this approach that utilized much of the accuracy of the CNC turret to remove multi-part and forming tolerances. The result was a single factory worker could assembly the entire frame and cardcages within 90 minutes – no fixtures and no drilling. The finished frame and cardcages were more accurate then any previous supercomputer that Cray had built.
Cray was acquired just prior to completion. The small system computers went to CGI while this supercomputer went to Sun Microsystems. We complete the final stages of this program under the direction of Sun. Sun changed the color scheme and maintained the mechanical design and manufacturing methods.
The image above was of the original Cray (color scheme) prototype.