On Fri, 8 Jan 1999, Simpson, Joel wrote:

> I am considering a project to use pics to decode forcefeedback signals
> from a computer (video game)that are typically fed into a joystick and
> instead use the information to drive actuators attached to a "cockpit".
>
> My question is whether anyone knows what kind of actuators would work
> for such a project and whether anyone has experience with circuits for
> driving hydraulics or slides.

imho hydraulics are a pretty bad idea for this, unless you plan to cope
with serious trouble during development. They are POWERFUL. Shop air is
less bad and makes less of a mess (but more noise).

> I have found some helical hydraulics (used in excavators), which I
> imagine are far outside my personal budget.  The motion would be great
> for making the cockpit lean  forward, backward, and to the side, in
> response to the joystick position, if perpendicularly oriented.

Air cylinders that will move 200 lb with shop air pressures are availbale
and the price won't kill you. However you need to plan the power plant
(air) and the control system. Just turning solenoid valves on and off
won't do for your application, imho, and a proportional air control will
set you back a lot of money.

Probably the easiest way to go is to get hold of antenna positioners
(electrical linear drives) or those servos used by experimental aircraft
homebuilders for various duties. Electrical = no mess (oil), no air,
direct control.

hope this helps,

        Peter