> In general there are always many ways for make something :)

For now what you can do is draw it in the "bent" shape from the beginning instead of thinking about bending it later on.

- Michael

It is a 1 rail sweep with a scaling rail.

>>How would you have done this without the scaling rail? I guess maybe NetworkSrf with 4 curves in each direction, or it looks like 2 rail sweep with 2 wavy rails.
<<

The last method is how I'd do it in Rhino.
It would be a 2 rail sweep with the same cross section profile as I used in MoI.
a circle for the finger hole and a wavy curve offset outside
of it -which would be more complicated to draw than the scaling rail curve.

The result of this kind of sweep in Rhino is somewhat unpredictable.
The waviness is an effect of the sweep, rather than a predetermined shape that
you can easily control,

-Jesse

Hey Jesse this looks great, I'm learning a lot of tips from this thread, thanks.

Hi,
I am a jeweller and am at last getting the hang of the workflow to make the sort of ring like the one of Jesse's above, building up one section on the circumference with booleans and then arraying it around the ring . I also got carried away with sets of boolean difference holes. When I come to add and subtract these decorations , if I do them all at once it never seems to finish calculating. If I do them one by one it still takes a long time for each.
Is ths what I should expect? It seems to be a fundamental ingredient of ring design, to gradually build up more and more complicated units and then build them together by using mirror or array, so do I expect it to take a long time?
I have not got the newest system but it has over a Gig of memory and a reasonable graphics card, so am I just over impatient!!

regards Tim.

Hi Tim, yes unfortunately the booleans do quite a lot of calculation so you can expect that they will tend to be slow.

> but it has over a Gig of memory and a reasonable graphics card

The boolean calculation speed is entirely dependent on your CPU speed, unless you run out of memory but I think you'd be fine at more than 1GB. What CPU speed do you have for your computer?

One thing you can do to speed things up if the speed is really getting in the way of doing your work, is to work on surfaces instead of solids, and then use Trim to cut only the surfaces that you know are slicing into each other.

Booleans basically do a lot of automatic Trim and Join operations for you, but they will tend to do a lot of checking for any intersections between 2 solids. You can kind of get more of a "fine-tuned" control over the process if you do the trimming and joining between surfaces yourself. But it is a lot less convenient, it is probably better to just wait a few minutes until the booleans finish.

- Michael

Hi Everyone,

I've been playing at making a fitted wedding band, but not getting the results that I want.
No doubt it's more to do with my lack of knowledge of how all of this works?

I've been trying to do it as a sweep, as that seemed to me to be the logical choice??
But I kept getting splits in the sweep where the band turns.
Here's 3 different versions that are progressions of each other.
Could someone please advise me of the best way to go about this kind of construction.

regards Colin

Hi Tim,

Just ask on the forum if you have questions about jewelry modeling in MoI, I may not have the answer, but someone will, so it will help others who want to learn, too...and then if enough jewelry designers ask questions, Micheal will know what tools to make for us! ;-)

I'm not sure if this is correct, but it seems that Boolean-ing parts in small groups seems to go faster (towards the end result) than doing them all at once.

Since many jewelry models are symmetrical, you can Boolean subtract things like azures for stones on one side of a ring and then trim away the other half of the model, slicing it right down the middle with a cutting plane, then mirror over the finished side and join them together. I've also build just a quadrant of a model and then mirrored or circular arrayed to complete it.

Another thing to keep in mind,- if you're CNC milling your models, Boolean unioning may not be required at all. I use ArtCAM which handles STL's that touch each other as one entity, so when you import the file to make a tool path,,it doesn't matter if the model was Booleaned unioned or just an assembly of parts before it was meshed.

Hope this helps.

-Jesse

Hi Colin,

I took a stab at your model.. I drew a planar curve approximately following your
3d curve. it consists of an arc, tracing the center of your curve and a freeform curve (through points) for the side section,
snapping to the end of the arc and then placing the second point of the freeform curve so that it lined up tangent to the arc.
That relaxed the bend where the band was crimping up and breaking.
It's off by less than 1/10 of a mm from your original curve.

Then I drew a circle for the finger hole, extruded a cylinder and trimmed the cylinder with the planar "profile".
I copied, pasted and joined the edge curves of the trimmed edge of the cylinder,
and then trimmed the copied curves at the 3 and 9 O'clock positions
of the ring. (quad points). I also trimmed the circle at 3 and 9, removing the top.

From there it's just one rail sweeps for each the top and bottom parts,
without capping the ends. Join both sections and you're done! :-)

Jesse

Hi Jesse,
thanks for helping, I hadn't thought abbout cutting away half or three quarters and then mirroring , that is the sort of approach I am asking about. I am now quite comfortable with the basics it is just what happens when you start to make your models more complicated that I find I have problems. I am milling these so I will try one as a group and see what happens.
I think the thing that would be the most help is groups, I seem to end up with a lot of stuff over 0,0 and have to zoom in very close to find it. Maybe a button that gave you 0,0 in a view would be a thought.

many thanks Tim .

Hi Jesse,

Thanks very much for doing the file & explaining how you went about it.
Just so that I understand correctly, this particular shape of ring "doesn't" really work with a straight forward sweep?
If so, I gather that's all because of the tight curved section at the top of the band??

Also, if doing this same design in Rhino3, would you construct it in the same way as you have in MoI?
Sorry for the questions, just trying to get a better understanding as to "what, how & why" works.

Thanks again.

regards Colin

Hi Colin,

You're welcome.

If you mean by a "straight forward sweep", a two rail sweep, it will
work that way as well. It would also work the same way in Rhino.

It wasn't so much the tightly curved section that caused it to break,
your curve has a kink where it transitioned over the shoulder towards
the side of the ring. I just tried it again with your curves as a two rail sweep.

I <separated> your curve and replaced the kinky section with a <blend> line that
makes a smoother transition (with tangency) and the 2 rail sweep works better,
but the surface still has a little bump in it that you could easily fix with a hand file in the wax.

If you drew the curve completely over, you could get it to be smooth as a 2 rail sweep. (see 2nd file)

If the design was a more complicated free form shape, perhaps you'd have more
control over it with a two rail sweep, but for this one, a one rail sweep worked OK.

Since everything was in place after I did the trims, I just swept the two sections
as one rail sweeps and joined them, but if you did it as a two rail sweep
it would take about the same amount of steps and accomplish the same thing.

The thing to always remember is, good construction lines make good surfaces. :-)
The key to making good construction lines is to let MoI "draw" the hard stuff
with blends or tangency or whatever other feature that seems most useful and appropriate.

-Jesse

Hi Tim,

Yeah, making a component that needs multiple Booleans and then duplicating it with
mirroring can save some time. You could also cut a ring up in small pie-wedges (going out from the origin)
if the section was complicated to Boolean and then array it around a ring and join up the surfaces.

I can think of one ring I did like that that turned out pretty good. It was an antique eternity band
with marquise stones and lots of little filigree that someone wanted in order to replicate their great-grandmothers ring,
which was all worn out. If I had to Boolean out all those little holes, I would would have had a melt down, if my CPU didn't first! ;-)

What do you use for your CAM program?

ArtCAM converts STL's to reliefs before it runs a toolpath,
so I believe thats the reason it can combine meshes on the import.

I'm not sure about the stuff over 0,0.
I have a script for Rhino3 that locates the lowest "Z" point of a model,
would that be what you mean? I use it to place the ground plane for a rendering.

You can assign a keyboard shortcut or an alias to 0,0,0 in Rhino as well,
if that's any help.

-Jesse

Hi Jesse,

thanks for the reply, I can see that with ever more complicated designs that doing multiple booleans is inevitable. I only get a small amount of tome to spend learning all this , I do get sidetracked by having to earn a living!! But I am getting there. Using MOI has finally made me understand Rhino, I have played around with other software but I have waited for Rhino4 to come out before buying, I will still buy a copy of MOI when it comes out ,it is developing so fast, and Michael is so responsive to requests!! Congratulations Michael!!

I am using Modela Player for generating toolpaths, and I have bought a Fourth Axis attachment for my MDX-20 so I am learning to use their FARM program, ( which lies to the computer and says it is an MDX-40 plus a bit more). Up to now I have mostly been doing reverse engineering for my hand wax carving. I have tried Artcam pro, I went on a short course and i did like it but I can't justify the cost.

I said that about 0,0,0 because I found that if you build a ring around it you keep using it as a main reference point and in the end it gets buried under lots of geometry, if MOI had layers it would not be a problem , it was just a thought

regards Tim.

<< I said that about 0,0,0 because I found that if you build a ring around it you keep using it as a main reference point and in the end it gets buried under lots of geometry, if MOI had layers it would not be a problem , it was just a thought>>

As a work-around until there are layers, you could try saving your model in stages, and only importing
the parts that you need as a reference to build the next stage.

As in the tutorial I did of the signet ring, I've sometimes drawn squares off the grid, in the lower
right corner of the front viewport to use as "job boxes" to hold the various stages of a model.

That way, you have a copy of everything, so if you wanted to delete the stuff at the origin and just
work on one thing at a time, you could. It's not that hard to select a box of parts and copy it from the center of the box to the origin,
but I'll admit it takes some extra modeling discipline to actually do it. :-)

(The boxes would work for most rings and jewelry in general, however, with more complex scenes,
it might be difficult for the display to shade all the parts if you had a lot of boxes).

Another thing you can do to make it easier to work on a particular area, is to select the parts you need to look
at and then do an <invert> and <hide>, which temporarily hides the parts which are visually blocking you from doing your work.

Did someone come up with a shortcut key that does invert-hide as one task?

-Jesse

Maybe this can help you :)

H ----> hide invert selection
I ----> Invert selection
Space----> object visible : Select all / Deselect all
(if letters are not used for other shortcut else just change the letters)
And at last you can use the icon "Hide" when you are lost :)

you can add folowing (3 lines)
in the .....\Application Data\Moi\moi.ini in section
[Shortcut Keys]
H=script:moi.geometryDatabase.invertSelection(); moi.geometryDatabase.hide(); moi.geometryDatabase.selectAll();
I=script:moi.geometryDatabase.invertSelection();
Space=script:var selection = moi.geometryDatabase.getSelectedObjects(); if ( selection.length == 0 ) moi.geometryDatabase.selectAll(); else moi.geometryDatabase.deselectAll();

Have fun combinatory selections :)
Very powerful before some system of manage objets :)

Re: the clock alarm video, am I missing something? I wait and wait no video. Just a bar going across the bottom. I have no problem playing other movies.

It works fine, just seems you have not the codec !
And yes you must wait the complet loading!
but sorry I don't remember the codec name :(
I will try to refind it !

Yeah ! it is this one !!!
http://www.3ivx.com/
Have fun learning!

Thanks!

-jdk