In 1999, we rebuilt Juggernaut to be
larger, stronger, and more dangerous than before. We abandoned our
traction technique and moved on to using a counterweight in a more
traditional form.
Juggernaut2 includes many more support triangles, a much heftier arm
(build now with long two-by-sixes), a winch, and a trigger mechanism.
Unlike the original, this was designed to fit into a full sized pickup
instead of my little Ford Explorer.
Here we are attempting to lift the original concrete counterweight
(estimated at 600lbs) in the air with a fairly simple arm. Look at
that bend. It broke soon. You can also see most of the old frame
still in use.
Next, we added more framework a bigger arm, and then created a
draw-down mechanism. It's quite simple (thank goodness.) A boat
winch into an 8 to 1 pulley hooked onto a slide-down cable. The
sliding cable idea was taken from pictures found on the net of
recreations of ancient machines. It also has the advantage of
minimizing the amount of cable which is needed to draw the arm down.
When the arm is up right, it doesn't take much to pull the arm a
little. When more force is needed, the draw down rope slips farther
out the length of the arm, increasing the leverage.
And here is our 160ft toss using approximately 180 lbs of counter
weight and a human-trigger.
When we loaded up the counterweight to a full 550 lbs, however, we
broke an eye screw holding our sliding cable!
So we fixed it with a 10$ eye bolt with a 2200 lbs working load
limit. Take that!
The next order of business was a trigger mechanism. Since we could
now draw down the 550 lbs, we needed a real trigger. This wheel
trigger is described in detail for ballistas in "The Book of the
Crossbow." The trigger line is looped over one tooth of the wheel
while the wooden lever prevents the wheel from spinning. To fire,
push down on the right side of the lever, the wheel spins, releasing
the arm. We originally used a bit of clothesline for the trigger, but
it stretched too much.
Juggernaut2 ready to fling a milk jug.
To see some more images of Juggernaut2, visit the
How To build a Winch page.
After all that preparation, check out my view of the
1999 Punkin Chunk which we attended.
Contains images of our machine, and some competitors which I thought
were interesting.
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