In defense of the 100G number... I'm not a mechanical engineer, but I am a Computer Science Engineer :) > I know nothing about rocket engineering, but I have trouble believing > your average off the shelf 2.5" hard drive can handle a medium sized > rocket launch of this magnitude. I imagine in addition to the G forces > associated with the launch there are all kinds of vibrations and heat. > My guess is that the 100G operating shock on a hard drive was measured > under very controlled lab conditions and doesn't carry over to a real > world rocket launch. Smaller items have less mass therefor the stress on them is less. The same hard drive made the size of the old Super Eagles (500MB drive that was 6U high and 18" wide) could not withstand the same accelleration. Basicly as the mechanics become smaller they become better. (They also become faster, less distance to move.) For instance, the arms the heads are on. When they are 9" long (for the super eagles) the force on the joint end is MUCH greater than when the arm is 1.25" While it is 100Gs done in lab conditions. Engineering specs like that tend to UNDER estmate what they really think it can do. Because if someone builds to that spec and it fails at 90Gs they can be open for losing some money. One princpal of engineering is to over estmate values you want to be small, and underestmate values you want to be large. Gives you some CYA room. Also the value of 100Gs is lacking a standard devation, ie 100G +/- 1%. > But I'm just hand waving and speculating, the biggest thing I've > launched is a 14" estes rocket in high school.. what the hell do I know. > :) Yea, the higest power Rocket I've ever done was D engines. johno
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