legodavee123 wrote:Arkov wrote:So if a mold cycle is 8 seconds it means that mold was running for a little over five years
I get 3.8 years-- 120,000,000 elements made = 15,000,000 individual runs = 120,000,000 seconds spent = 2,000,000 minutes = 33333.333 hours = 1388.888 days ~ 3.803 years.
Of course, I've got no idea how long that means in "real" years. I tried running some stats using BrickLink data, but there's just not enough useful information available to make a prediction. But probably safe to assume that a typical mold's lifespan is in the ballpark of 3-10 years?
Different molds wear at different rates, so some will last longer while others get retired sooner, but lets assume it's accurate for this one and not just made up for the tour. legodavee123's math is right: the working time for that mold was 3.8 years, assuming 8 seconds per cycle... but keep in mind that's a guess. An educated one of course, but still a guess. If that's off by even a second, that changes the lifespan by almost half a year. I'm not trying to be a total buzzkill but the fact is these numbers are anything but certain. Also, they're obviously not running any single mold continuously, 24/7, for it's usable lifespan, which is why the molds true lifespan is much longer than the time calculated here. This is worse than a guess because my memory isn't spectacular, but I seem to remember some interview stating that the molds tend to be replaced after 10 to 15 years for most parts, while rarer ones last longer (because they get used less frequently).
More interesting, using turtle's estimates of mold cost, if this one is a $5k mold that works out to .004 cents per part over it's lifespan. Even for a $100k mold at an assumed lifespan of 120M parts like the one above that's still only .08 cents per part. So even though we're spitballing here it's pretty clear they have the cost of molds covered easily from a line item point of view. Storage, handling and maintenance of them is another cost to consider but that too will be spread very, very thin considering the volumes LEGO produces.