Re: Rhino, etc.
Posted by
Andrew Werby
on 1999-09-05 03:41:30 UTC
Arne wrote
5. CAF: ( Ian, - et al )
I just downloaded Rhino demo, and I will check up the other stuff,
and yes - you are right about the objects and stuff. I was thinking
of a much easier application to use. I just bursted out some ideas
:-)
[Rhino's not hard to use once you figure out a few things about how it
works. Some hints:
When navigating within a viewport window, things get weird once you rotate
the view (using the arrow keys.) You think you're moving something one way,
but from another viewpoint it's way off. What you need to do is issue the
command "cplaneview" to orient the view before moving things. I find it
helps to set this command up as a shortcut key, using the Tools/options
menu.
If you're trying to place a point in space, depress the "control" key while
clicking in one view. This establishes its position as far as that view is
concerned. Then, with the key still depressed, move the point in another
view. If you do this right, you will see a white line stretch from the
previous position to the current one.
Right-clicking on the viewport title ("Front" ,"Right", etc.) brings up a
menu that lets you maximize the view, revert to preset views, etc. The
page-up, page-down keys zoom the window in and out. Holding down the right
button and dragging will move the object view in an unrotated (preset)
view, or will rotate it if you've rotated it already. You can do these view
changes in the middle of a command, which enables you to see what you're
doing.]
But, let us keep to it for a moment, - the parts you pick up,
[From where?]
could just pop up an input window - diameter please: , length : ,
etc. And it snaps on the centerline. You could also have a roller
bearing icon, - just enter the size, and the computer enters what
needed for the rest. You don't have to have any drawing
environment.
[I'm not sure what you'd be doing with this roller-bearing, lacking a
drawing environment- milling it out of a block? ]
I thought more of something you could do on the
"floor", on the machine center. Not something you had to fire up a
CAD program package to use, and it would produce the G-code direct.
This desktop could mimic your machine center, as where tool pockets
are placed. Do the hole thing.
[There are programs (like Visual Mill) that do this- simulate the
toolpath, place pockets. You don't need to go back to the CAD program for
it, and it produces the G-code. I'm not sure if you can modify g-code
programs while they're running, but you can always start over.]
I speak out of ignorance - I have not been working at a machine
center, and know little about it, - but the way I see it, there is
some trouble with CNC. Often you could do minor jobs manually, -
but a CNC machine will not give away the control that easy :-), so
I was thinking of some sort of entering programs, in a more easy -
on the fly - environment.
[My old mill works like that- you enter g-code manually with the attached
keyboard/pendant. I'd rather the whole thing was automatic- it's too easy
to screw up trying to figure all this out in my head.]
6. NURBS
Ok, Rhino uses this. What packages are great with solids ?
[Have you looked at SolidEdge?]
NURBS looks good for 3D, but not so good for mechanical parts ?
[Compared to what? NURBS are better than polygons for mechanical
applications, because in order to approximate a curve (like the teeth of a
helical gear, for instance) a polygon application has to stack a finite
number of angular polygons along a path, but NURBS define the curve
mathematically, so that if one zooms in it will always look like a curve,
not a series of flats placed at angles. These discontinuities can interfere
with the function of a mechanical part, if not enough polygons were used to
achieve the required tolerances. Using a huge number of polygons tends to
bog down computers, so usually one must compromise, which is a constant
balancing act. Solids modeling programs do have certain advantages over
surface modelers like Rhino, notably parametrics (which allow one to change
the attributes of a complex assembly by modifying a single parameter) but
they are in a whole different price category.]
( it will take some time before I understand what rhino can do )
[Me too, and I've been using it for more than a year now. (of course they
keep improving it, so there's catching up to do.) Fortunately, the
technical support you can get from the forum on their site is excellent,
with other users as well as the writers of the programs willing to share
their expertise and suggest ways to accomplish whatever it is you're trying
to do.]
//ARNE
Andrew Werby - United Artworks
Sculpture, Jewelry, and Other Art Stuff
http://unitedartworks.com
5. CAF: ( Ian, - et al )
I just downloaded Rhino demo, and I will check up the other stuff,
and yes - you are right about the objects and stuff. I was thinking
of a much easier application to use. I just bursted out some ideas
:-)
[Rhino's not hard to use once you figure out a few things about how it
works. Some hints:
When navigating within a viewport window, things get weird once you rotate
the view (using the arrow keys.) You think you're moving something one way,
but from another viewpoint it's way off. What you need to do is issue the
command "cplaneview" to orient the view before moving things. I find it
helps to set this command up as a shortcut key, using the Tools/options
menu.
If you're trying to place a point in space, depress the "control" key while
clicking in one view. This establishes its position as far as that view is
concerned. Then, with the key still depressed, move the point in another
view. If you do this right, you will see a white line stretch from the
previous position to the current one.
Right-clicking on the viewport title ("Front" ,"Right", etc.) brings up a
menu that lets you maximize the view, revert to preset views, etc. The
page-up, page-down keys zoom the window in and out. Holding down the right
button and dragging will move the object view in an unrotated (preset)
view, or will rotate it if you've rotated it already. You can do these view
changes in the middle of a command, which enables you to see what you're
doing.]
But, let us keep to it for a moment, - the parts you pick up,
[From where?]
could just pop up an input window - diameter please: , length : ,
etc. And it snaps on the centerline. You could also have a roller
bearing icon, - just enter the size, and the computer enters what
needed for the rest. You don't have to have any drawing
environment.
[I'm not sure what you'd be doing with this roller-bearing, lacking a
drawing environment- milling it out of a block? ]
I thought more of something you could do on the
"floor", on the machine center. Not something you had to fire up a
CAD program package to use, and it would produce the G-code direct.
This desktop could mimic your machine center, as where tool pockets
are placed. Do the hole thing.
[There are programs (like Visual Mill) that do this- simulate the
toolpath, place pockets. You don't need to go back to the CAD program for
it, and it produces the G-code. I'm not sure if you can modify g-code
programs while they're running, but you can always start over.]
I speak out of ignorance - I have not been working at a machine
center, and know little about it, - but the way I see it, there is
some trouble with CNC. Often you could do minor jobs manually, -
but a CNC machine will not give away the control that easy :-), so
I was thinking of some sort of entering programs, in a more easy -
on the fly - environment.
[My old mill works like that- you enter g-code manually with the attached
keyboard/pendant. I'd rather the whole thing was automatic- it's too easy
to screw up trying to figure all this out in my head.]
6. NURBS
Ok, Rhino uses this. What packages are great with solids ?
[Have you looked at SolidEdge?]
NURBS looks good for 3D, but not so good for mechanical parts ?
[Compared to what? NURBS are better than polygons for mechanical
applications, because in order to approximate a curve (like the teeth of a
helical gear, for instance) a polygon application has to stack a finite
number of angular polygons along a path, but NURBS define the curve
mathematically, so that if one zooms in it will always look like a curve,
not a series of flats placed at angles. These discontinuities can interfere
with the function of a mechanical part, if not enough polygons were used to
achieve the required tolerances. Using a huge number of polygons tends to
bog down computers, so usually one must compromise, which is a constant
balancing act. Solids modeling programs do have certain advantages over
surface modelers like Rhino, notably parametrics (which allow one to change
the attributes of a complex assembly by modifying a single parameter) but
they are in a whole different price category.]
( it will take some time before I understand what rhino can do )
[Me too, and I've been using it for more than a year now. (of course they
keep improving it, so there's catching up to do.) Fortunately, the
technical support you can get from the forum on their site is excellent,
with other users as well as the writers of the programs willing to share
their expertise and suggest ways to accomplish whatever it is you're trying
to do.]
//ARNE
Andrew Werby - United Artworks
Sculpture, Jewelry, and Other Art Stuff
http://unitedartworks.com