Originally when designing Q1 I had planned to use a knife edge suspension as the
pendulum support. Instead, I decided to use a form of cross spring suspension known
as the C-Flex bearing. These suspensions are manufactured in many sizes and it originally
seemed like an excellent choice for the suspension because the pendulum movement
was limited to a few degrees and the forces on the spring were quite small.. Given
these parameters, the bearings should last forever. There is a small restoring force
associated with this type of suspension and I originally felt that the effect would
be minimal. After running the clock, my experience was that the restoring force,
although very small, affected the rate in an unpredictable way. It's possible that
there was a temperature component to the effect but I couldn't see any real pattern
and decided that my original idea of using knife edges was a better way to go. Late
in 2005 I changed the C-Flex bearing suspension to a knife edge suspension and almost
immediately saw an improvement in the stability of the rate. I also considered using
a Fedchenko style suspension but wasn't sure how it would work with a Schuler pendulum
and ultimately decided not to use it.
The new knife edge suspension for Q1 which replaced the C-Flex bearings.
The original crossed spring (C-Flex) suspension which created minor stability problems
in Q1.
Flex bearings are constructed utilizing flat springs which are locked and crossed
at a 90 degree angle and encapsulated in a cylindrical steel housing. A cutaway on
the left shows the construction of the C-Flex bearing. Using them seemed like a good
idea!
