It is not as hard as you think Monty. I have solved most of those
problems.
It took me a while to catch on.  I had to or they would not work in
the stereo lithography machine. A lot depends on the order in which
you do things.
The books don't tell you that. That took me awhile to figure out.  One
of the tricks is to scale the part down and "difference" it from the
real part to form a shell. You scale the different axis's at different
rates.
I got so I go do these things in a few hours.

Here are some complete solids in Rhino. All my castings had to be
complete
solids or they would not work in the SLM. It would be nice if there
were
a shell command in Rhino like found in Solid Works.

Also the people at Rhino told me they have made improvements
for some of  those problems in the later versions. I have been so busy
upgrading my NC mill lately I have not got around to upgrading.
I am still using version 2. There is no doubt in my mind with a little
more development on Rhino's part that it will do what solid works does
eventually and with a much better and easier to learn user interface.


Paul Lamar

Paul,

It's not really a question of whether or not it can be done. Building solids
in Rhino from surfaces is the way you used to have to do it in UG. So I have
plenty of experience doing it that way. In UG most of this effort is
automated. For instance to make the shell I would model a solid then hollow
it out. If I want ribs I extrude and add them. Then put a blend around the
rib. If I move the construction curve in UG the whole thing updates, with
the rib in the new location. Or I can replace the construction curve and the
rib takes the new shape automatically, blends and all.  That same task in
Rhino would see me deleting the rib and blend surfs. Then untriming the
shell surf. Then creating that geometry all over again. Then re-joining all
the surfs to make a solid.

 What if I want to make the part .08 in thick instead of .1. I would have to
rebuild everything. In UG I just change the thickness parameter, everything
updates. Rhino is a great package, but parametric solid modelers are a
requirement for what I do. It is a time issue. I agree Rhino has improved
the blending ability in recent upgrades which I have. But in UG I have many
options: regular spherical blends (as in rhino) except with parametric
variable radius capability, variable conics, soft blend (follow a specified
tangency curve) face blends, cliff edge blends(blends where one edge is not
tangent). All of these have the capability of just changing the parametric
radius and they update. Or have different radiuses at different points. Or
change the degree of the conic along the blend using a specified function.

Believe me if Rhino were capable of these things I would use it.

Yes true my fix is a kludge. It would be nice if it had a shell
command
and could do all those other things.

Paul Lamar
 
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