codygo wrote:
I can practically guarantee that there's no cost saving in that ugliness other than not having engineers that know how to design smooth organic surfaces. That kind of modelling is a very niche skill reserved for industrial designers (people who specialize in product and automobile body designs) but most mechanical engineers THINK they can do it, and the result is products like what you've shown here. I've seen more than my fair share of fugly CAD from engineers with many years of experience, but no training in this type of modelling. In the engineering realm it doesn't seem to throw up any red flags.
Another thing that may have occurred, is that it WAS originally designed by a group of industrial designers based on aesthetics, but once the surfaces were handed to engineering and they ran FEA optimizations the changes only propagated to the chainring interface with a positional constraint, and no consideration was given to realign the crank arm surfaces to have tangency (and G2, or even G3 criteria).
Looks more to me like there is a nice design there, but they are not correctly compensating for the shrinkage that occurs as the metal cools from the hot forging process. Aggravated because it is hollow. It doesn't shrink right at the edges of the chainring and spider because there's a bulkhead there, so you get some pull-back and change in angle behind the interfaces. In the spider arms you see some ripple, that definitely looks like shrinkage artifacts.
Brian
Gonna buy a fast car, put on my lead boots, take a long, long drive
I may end up spending all my money, but I'll still be alive
