your cabin should be designed to fit your needs. Mounting to a Pedestal
For this particular simulator, I chose a pedestal
mounting system (Figure 6). This is nothing more
than a scrap automotive universal joint (as you
might find on a drive shaft) from a junkyard.
Usually, these cost little or nothing.
I hired a local welder for a few dollars to cut
and weld this shaft to a large metal plate. Looking
again at Figure 2, note that the pedestal is not
centered under the cabin. It should be mounted so
that it is far enough back on the cabin that some
weight will always be on the front pitch cylinder. By
keeping the cylinder under constant load, you will
always have control of your platform’s position.
The same is true for your side roll axis. As seen
in Figure 7, the pedestal mounts slightly behind and
aft of the rider and simulator’s center of gravity to
keep both the pitch and roll cylinders under
constant load. You will also notice in the photo that
I had two chains and springs attached to keep an
additional load on each cylinder at all angles.
You may or may not find this necessary, but
since I wanted a wild ride, I added the springs so
that the tilt of the cabin would be as rapid and
wide as possible on the return stroke of each
cylinder. The Electronics
Thanks to Weeder Tech — whose ads I found in
Nuts & Volts years ago — electronic connection of
the original simulator to the computer was
extremely simple. Let’s briefly talk about what the
electronics do.
The Virtual Flyer is a complete closed-loop
system, which is to say that the computer running
the simulation monitors the exact position of the
simulator platform and adjusts that position to
match events on the screen approximately 20 times
each second.
In order to accomplish this, your computer
simply needs an input/output module capable of
opening and closing the four air valves that move
the simulator. It also needs to read the position of
the platform via two feedback potentiometers.
Figure 6 shows the two feedback
potentiometers on the base of the simulator.
Attached to each potentiometer is a heavy
armature and a length of chain that attaches to the
base of the cabin.
One chain is attached to register pitch
April 2014 43
; FIGURE 7.
; FIGURE 6.