As some of you know, my primary hobby is building and driving radio-control cars and trucks. My primary area of interest is a highly specialized type of vehicle known as rock crawlers, which as the name implies, drive very slowly over rocks.
In competitions, the truck bodies, which are made of vacuum-formed Lexan, are allowed to be trimmed to 70% of their original size, to allow for tire clearance, etc.
The question is, how does one measure something as irregularly shaped as a truck body to an exact spec, in the field? The difference between a 70% trim and a 71% trim could constitute enough of a competitive edge to disallow a truck in a competition, so precision is necessary for the measurement. Speed is also an issue, with 40 or 50 trucks to measure a tech inspector could be all day on body detail.
The bodies are painted with different kinds of paint, and more or less paint affects the weight of the body. Therefore, simply weighing a pristine body (as I proposed) and using that as a baseline leaves plenty of room for error. A competitor could run an "illegal" body with a couple of stickers to make legal weight.
The weight itself is not the issue. The issue is having a body that still has an intact cab and fenders, but allows the wheels to travel without rubbing. This is the "spirit" of the rule. Many competitors cut the doors off halfway down so the body will not get snagged on the ground, and thus does not look like a truck anymore, at least not one that's above water.
Defining the 70% rule has been the subject of much debate here:
http://www.rccrawler.com/forum/showthread.php?t=20478
but we are still a good ways from a definitive answer.
I thought I would tap some of your keen and penetrating minds, since you like to measure things. Let's see how you do with an irregularly-shaped three-dimensional object.
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