Rubber testing - some info

From: <mkirda_at_sbcglobal.net>
Date: Wed, 14 Nov 2012 05:31:45 -0000

Greetings.

Jeff Annis sent me the spreadsheet he uses for computing the energy level of rubber.

After some false starts, I have learned a few things.

1) Three of the four batches of rubber are nearly the same at near 4000.
2) 6/12 Tan SS is the worst at 3400 at best.
3) A second wind immediately after the first may get you 200 more turns, but energy return is significantly (15%) less. With the Tan SS I have, you really run the risk of breaking the motor - which somewhat explains the problems I had earlier I thought were related to the o-rings I was using.

I have been winding ~.054" motors to .55 or so in-oz of Torque, then unwinding 20 turns at first, then 50, sometimes up to 100. After unwinding, it takes some time for the torque meter to steady. A light thump on the rubber seems to make is stabilize quickly. A lot of data points are involved.

I'll probably share the data after I compile some more.

Regards.
Mike Kirda
Received on Tue Nov 13 2012 - 21:31:47 CET