Hello everyone welcome back to PJ's Rhino3d class. Follow-up the question
couple videos ago regarding how to hollow the back of the ring. I would like
to talk about the commands called "shell" in Rhino. And again if you're using the
RhinoGold or GemVision Matrix, you probably don't need to use this method
because it does have the command for hollow the ring. However this tutorial is
for Rhino3d user and of course you will learn a lot going through all the
video. Even though you're using Matrix or RhinoGold. Let's get started.
before we get to hollow the ring let's take a look on this command called "shell" and
"Shell" is really strong command it. I think is starting from rhino 5. What it
does is you can hollow out inside of the shape and make it consistent thickness.
so let's try the first one I'm going to use the "shell" command. Lets just type it
shell s-h-e-l-l, and then thickness that set it as 1, or you can change the
thickness. You could go ahead and pick up the surface you want to shell and then it
will go all the way inside. Alright, it applied to the polysurfaces or the
shape after you boolean so let's try this one too. This time, I want to
pick up the same command you just hit enter
Alright, click on your mouse you can bring up the latest command you use. I
want to shell not only one place, I actually want to shell three faces. So
let's take a look it will shell all the way inside of that shape. One of
the restriction is when you're using the shell you need to have a flat surface for
example this sphere I wanted to shell it's no way for me to shell it. Let's try
since this is completely round the Rhino doesn't know
where do you want to start it. So it has to have a flat surface. so let's take a
look on this one I'm going to shell and I pick up this flat surface and again it
will shell all the way follow the shape of what I want. Now there's a restriction
when you have a combination for the strip and the curved surface when you
try to shell, for example, we want to shell from this flat surface and then that
would be no problem go all the way inside, or if you want to shell this
surface, which is all the way flat and you will have no problem either. However,
if you try to shell on the surface that has a curve and also straight edges then
you might run into the problem. Let's take a look it will tell
you the shell result is not solid. So let's take a look where it's not solid.
It probably will leave it...,and let me turn on the ghost view, and it will
probably is right there. if you take a look underneath it that part will not be
solid. So let's talk about how to shell this signet-ring. It is a simple form
there's no extra cutting on the top or anything's like that. We want to use the
shell and remember one thing, when we are making any of a model we try to make
bottom half of a ring shank as solid as possible. Two reasons, first one is because
when you are sizing a ring the one on the bottom usually get cut either is
adding more metal or remove the metal .So let's try to keep it as solid as possible.
Second reason is if you make it hollow, it's easier to get dent, because that is
the part hit the other places the most. Alright, so we want to keep the
bottom solid. Now to do that if we shell entire inside of a ring your shell all
the way to the bottom, so we need to split this first, I'm going to
use the curve from mid-point and snapping into the zero and draw a line across is
wider than the ring shank. Then I'm going to split this ring by this curve so now
I have top in the bottom. To show the better view I'm going to hide this one
so you can see the bottom is gone, but make sure that you close this
because for "shell" you need to make sure that they are solid. so I'm gonna use the
command called "Cap" I'm gonna type a cap and click it here. Let's use the command
"shell" let's set the thickness for 0.8 millimeter and then lets going to
click on this surface. then you will get this ring is hollow out from inside all
the way. Then lets also turned on the bottom. Remember the bottom, since we
split it. It's not solid, so lets do "cap". first make sure they are solid then we
can go ahead to "BooleanUnit", so that's how we get this form to be shell all the
way the same thickness. Now let me move this one on the side, and let me bring
up another one
to shell this ring will be the same we can use the "shell" but you're gonna
running into one of the problem, and of course we can split the ring like the
first one, the top in the bottom, but the problem is if you're going to look at
inside of this interior right here, It has a lot of sharp corner and the
distance, for example, where the P, the straight bar there, it is less than 0.8mm
than we wanted to shell, then you will run into a problem. Let's
take a look what kind of problem will run into it. To save your time, I'm not
gonna cut the model in half I just want you to see, so lets type ,it "shell" then
the same thing we use 0.8 millimeter. okay here said
"shell result it's not solid" and let's take a look on it. It's because this complicated
design right here, and as some of the distance is smaller than the distance we
want to shell, and so you will get this broken edges right and of course we are
not gonna use that. So that's undo and the way we are going
to work on it, is we need a clean cutting tool, so let me move this
outside, and what's the clean cutting tool is the original one that we have
not cut out the texts. We're going to use this one as our cutting tool. So I need
to bring this ring back. So I'm going to use align tool and snap them back to
the zero point and let me move this one up a little bit. Alright so that way I
have two pieces. One of the piece is with the text, and the other one is a clean
cut. I'm going to change the color for that clean cut into the red one. Okay, so
let's take a look at the front view. I'm going to scale it down. Holding my SHIFT (key)
so I'm scaling down all the same distance, now we don't want to
cut it too low to the bottom, so I'm going to scale 1D to bring it down a
little bit and bring this up. Alright, in this result it may not have exactly
the same distance all the way but it will work too, and so you can use the Gumball to
do 1D scale to find the proper thickness that you want. With that
all we need to do is "Boolean different" so this one is boolean out by this one,
so then you will get a big chunk of the metal cut out to reduce your thickness,
and also at the end of where the hollow form will be rounded. In this case, you
will get sharp edges but you can always do fillet the edges to make it round
Remember always check the naked edges before you send it off for print
Basically you send everything into the edge analyze. Its living under "analyze"
you have "edge tool" and "show edge" and then you will show if it says this has no
naked then you are good to go to making them into the mesh. How to make
the ring into the mesh and prepare for the casting, please look at my other
video at the end of this video or see the link below thank you for watching. I
hope you enjoy the video please leave a comment let me know how I'm doing and
any other questions that you may have regarding this video or any other
techniques you would like to see in the Rhino3D
Thank you, I will see you next Monday.