"Subdued" won't be a monstrosity like 2002's Jumping Mechanism, but
it will be the big machine of 2003.
This is nothing more than three four bar linkages.
The final linkage has an inverted follower bar which
will move the coupler almost 90 degress out of parallel.
This motion will cause the prop to face forward.
May 18, 2003
The photos (above) show the Subdued machine after the first stages of assembly.
The photo displaying the machine in it's retracted state was shot immediately after
the major frame components were assembled.
The second photo (displaying the machine extended) was taken after witnessing the
self destructive power of this assembly's sheer mass. The design improvements include a continuous
1' X 1" cross bar to which both pnuematic cylinders will attach. The single 1/2" crossed linkage
(push bar) was replaced with a pair of 3/16" X 1" flat bars.
This machine is terribly overbuilt. (I bought too much 1 X 2 tubing and not enough 1 X 1 tubing.)
It's heavy ... it's strong ... it's a monster.
As you can see in the "retracted" photo, the majority of the machines bulk rests above the rear
cross member of the base. This limits the available cylinder throw that can be used.
A longer base would solve this problem, but it would also increase the machine's total length.
After much debate, I decided to work with the machine "as-is" instead of
making a bigger mess. After installing pneumatic flow controls and carefully placed
extension springs, this machine will operate smoothly and safely.
Two pairs of extension springs are used with this machine.
The photo of the machine fully retracted (above, left) shows
a pair of 1" X 12" X .105" zinc plated extension springs. These springs
aid in the initial lift of the machine.
The second photo (above, right) shows the second pair of springs
at work. These are garage door opener springs rated for 130 pounds.
Fully relaxed, they are 21" long. When the machine is fully retracted, the
springs are under no strain. These are used as helper springs. They "engage"
during mid stroke and are used to soften the end-of-stroke impact while
helping the machine reset.
This spring combination greatly reduces the affects of the machine's weight
during travel. The springs seem to "cancel" each other at approximately
mid stroke.
The photo at right shows the Subdued
machine prior to painting.
All of the components nest within the layer below
them. The result is a machine with a wider
stance at the base and a narrower profile
at the top.
The addition of a prop will help balance the load
over the center of the base. It will also
change the center of gravity when the machine
is fully extended.
Despite the fact that most of the machine's weight
is directly above the base at full extension, the momentum
generated during travel causes the rear of the machine
to lift at full extension (at "full" speed)
The addition of pneumatic flow controls
will reduce this side affect - keeping all feet
on the ground.
Below are a few photos of the Subdued machine at completion.
Finished Prop Measurements
Retracted / Extended
high ..... 14" / 73"
wide ..... 70" / 70"
deep ..... 71" / 76"