Graeme,
I'm building A198 - now moved with me to Market Harborough, and I've been
studying/worrying about the overcenter (OC) position and have come to the
same conclusion about the marginal amount of factory designed overcenter
provided. I believe this might be a compromise - as too far overcenter and
you fight the shock cord tension to raise the gear. While the machining of
the gear components is quite precise, I believe the stops are part of a
weldment - which is considerably less so.
Overcenter toggle clamps used for holding products being machined or
assembled in industry have adjustments that control the degree of tension
against the arm that puts pressure against the OC condition. There is an
adjustable nut to control this - Locking pliers the same way. Hit them hard
or vibrate these devices and they will open if the adjustment isn't such
that the lock is firm. The gear lock in the cockpit does not put pressure
into the joint, so while it helps, it's really a 'late' way to save the day.
It does not modify the geometry of the parts by forcing increased pressure
into the components.
When there is no weight on the wheel, pressure into the OC condition is held
in the static state by the shock cord. I would submit that the degree of
tension on the shock cord has a significant bearing on the integrity of the
system. And the criteria for shock cord tightness, is only the degree of
'effective assistance to raise the wheel' .
I am considering going further OC on my ship, however, that will require
repositioning the gear handle half the four bolt holes, or less, so will
likely require pinning. It also means that 'popping' it out of the OC
locked position will be more difficult when trying to raise the gear. Of
course a better solution is to put pressure into the system. This could
possibly be done inside the cockpit with an OC clamp on the gear lever -
with the slot modified to allow it to be pulled rearward.. The clamps I
referred to above come in a J-hook pull style, which could keep rearward
pressure on the Gear lever in the aft condition. Giving correct meaning in
the Mono to 'Gear down and Locked'.
Cleve Lee
A198 Mono XS Jabiru 3300
Wings closed, top on, sanding...sanding...sanding...
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