"Jake" wrote in message
ps.com...

I can't remember the name but someone mentioned Legos and the Technic
pneumatic pieces - that's a stunning idea. I'll try that out as far as
prototyping goes to get the structure/design/frame figured out.

I would recommend you go in this direction before you invest some very
siginificant funds into something that could take years of work to get
going.


A couple of questions that just came to mind - or just one:

If you have two identical hydraulic cyclinders next to each other,
operating on the same object and working off of the same base, is the
net force just the sum of the forces of the two cylinders?
In other words, if I have a platform that is lifted by 4 hydraulic
cylinders attached at each corner, and each cylinder can exert a force
of 25 newtons, is the total force 25 newtons or 100 newtons? I think
it would be 100 newtons.

The only thing that matters is the area of the surface which is
perpendicular to your force and on which hydraulic (or pneumatic) pressure
is acting upon. In the case of a group of hydraulic cylinders, this is the
total area of all the pistons.

You should be aware of the forces you are (possibly) dealing with here.

Lets say a system pressure of 1500psi (~100 bar), a cylinder with a piston
diameter of 1" (~25mm).

F=pi*r^2*P

Whe
F is force in pounds
pi is pi (~3.14159...)
r is radius of pison (circle) in inches
P is pressure in pounds per square inch

F=pi*.5^2*1500
=1178lbs
(Which turns into roughly 5200N)

Obviously, this is a _lot_ of force. While it's fun to see rocks get
crushed, you may not personally enjoy the feeling. Hydraulic systems are not
designed to fail when they get bloody, so you really only get one chance
(and typing code without a full compliment of fingers must suck).

A guy at work recently got caught in an automatic surface grinder's
hydraulic feed mechanism. It nearly sheared his finger off.


Ok I'll let you guys comment now on how insane I must be to dream of
making something like this...

Well, at least you see what we're seeing. You should definately see what you
can do with this Lego Tecnics set (if it even exists). Anything that speeds
up the prototyping stage of development is going to be a _huge_ help.

You've got a lot on your plate...

Regards,

Robin