On Thursday, January 30, 2014 2:02:14 AM UTC-5, Alan wrote:

it does seem like a rather severely limited lifetime. They
should be using better parts to make their releases last longer - a lot longer.


10,000 is obviously a NICE ROUND NUMBER that some engineer picked based on the limited facts at hand at the time. It does not mean that the release will fail at 10,001 cycles, or even 20,000 cycles. 10,000 accounts for the inability to foresee the effects of the worse case abuse experienced by the TOST release in the field.

When the service person takes a look at the release after 10,000 cycles, they might as well replace the parts that might someday fail especially if that makes the customer feel that they got something of value for the expense of sending the release in for renewal.

Does anyone know what happens to the old springs? Do they get sent back to TOST and are a random sampling of them then tested until failure? The results of that testing would confirm that 10,000 was a sufficiently short service life. I doubt that TOST makes that evaluation based on uncontrolled failures in the field.