--- In Indoor_Construction_at_yahoogroups.com, "jabiruchick" <jabiruchick@...> wrote:
>
> Well I can imagine that the rubber stretches and expands and so if you strip off a length .050" wide and then wind it a few times, it wouldn't quite be the same width anymore, so mass would be a better way to express the amount of rubber.>>
Okay, but I presume you mean mass per inch, not overall motor mass. But even when you use weight or mass per inch, it still stretches after a few winds, and you're *still* not dealing with exactly the same cross section you start with. Therefore, I label a motor bag with its original (unstretched size) and don't worry about remeasuring, merely whether or not it's "broken in" or not.
BTW, I also often multiply my grams/inch label by 1.57. This will yield a nominal "micrometer reading," AS IF the rubber were a constant .042" or .043" (forget which thickness I chose to normalize with.) This works well enough for the measured density of my 5/99 supply. Other batches may require a different factor.
Mark F1diddler
Received on Tue Apr 27 2010 - 15:37:11 CEST
This archive was generated by Yannick on Sat Dec 14 2019 - 19:13:46 CET