Newbie to rhino- please help.

[kbillan]

greetings rhino users. I am a newbie to Rhino and am curious about a couple things.

I am trying to create a concave recess on the face of an object but every time i do, it wont let me trim the excess off AND its convex, not concave. I know its kind of a general question, and its tough to suggest a solution without seeing the actual drawing... and since i dont know how to show the drawing, ill show what i am referencing. I am currently drawing the buckle. I have the whole thing draw, except the recess around the center dial.

I do have one version drawn that has the convex recess- but it has a section that wont delete, and is not selectable... but its there..

http://img120.imageshack.us/img120/2179/cimg3586ur3.jpg
http://img120.imageshack.us/img120/c...jpg/1/w640.png

[kbillan]

Update- I have actually got the surface to be more concave by messing with the stiffness of the patch...so that might be all set... but it sill wont let me trim it nicely....

[spoiledbrat]

Without seeing your drawing, I am making a few assumptions. Please forgive me.

For drawing that buckle, I believe you will have better luck using the boolean difference functions. This is done by drawing two solids, one is the main part of the buckle, and the other is the 3-d shape that you want to subtract (or gouge) out of it.

This will automatically trim the edges for you.

For making the 3d shape that you want to subtract, I would create a sphere first. Then, I would "rebuild" it to get more control points. Using control point editing, I would flatten the sphere, and drag the upper corners out a bit.

Good luck,

Rob

[mc-motorsports]

Though you guys would find this interesting.
http://www.novedge.com/documents/3247/SKU/2555

[kbillan]

Though you guys would find this interesting.
http://www.novedge.com/documents/3247/SKU/2555

Wow.



I am LEAGUES away from that. Shows the power of the program though.

I drew my drawing out by eye.. but im betting the way to do it is to start with the pic.. huh?


I was able to get the drawing where it needed to be, but i now have a new project no thanks to mc-motorsports


and the bottom line is that i have about 1 month experience with this program and NO background other than 10 years ago running R14 in tech in highschool... so- its all uphill.

thanks for your replies..
Keith

[mc-motorsports]

Note that they were using a plug-in with Rhino. It was actually a link I recieved via email advertising for the T-Spline plug-in, which looks very useful in the right place.

But that's what I love about Rhino, it's very powerful, affordable, and you can build off the base software with plug-ins that relate directly to your needs... Instead of spending $5k plus on the competetor's software.

We all had our first month of learning CAD, your trying for some pretty advanced stuff already! Good luck, after 13 years, I'm still learning, but that's the fun part.

[kbillan]

Here is what i came up with from eye... its a little rough as i dont know how to make curves except through control points.. so this whole drawing was done that way.. the center part in the picture (black) was done in a separate drawing..

So this in essence was done using clever- rather than wisdom. LOL

not bad, for just getting into this. Plus i figure, with the roughness.. its going to have to be finished by hand either way to get the machining marks out of it... but i would LOVE to be able to do this properly...


http://img80.imageshack.us/img80/9924/phot1wb1.jpg
http://img80.imageshack.us/img80/pho...jpg/1/w640.png

[mc-motorsports]

You didn't want to use a bitmap image background? I figured you would want to make it as close to the pic you posted.

Do you have the belt buckle in your hand? Or are you just going off the picture? If your just using the picture, I would start by tracing a bitmap background and you just have to fake it and fudge it from there. If you gave 10 of us that picture, we would all have our own way or making a 3D model.

So your going to cut one? Do you have a CNC mill? Just an idea, when you have your final drawing, post over in the RFQ section and see how much it would cost to have someone make it for you on a 3d printer.

Looking good!

[kbillan]

You didn't want to use a bitmap image background? I figured you would want to make it as close to the pic you posted.

Do you have the belt buckle in your hand? Or are you just going off the picture? If your just using the picture, I would start by tracing a bitmap background and you just have to fake it and fudge it from there. If you gave 10 of us that picture, we would all have our own way or making a 3D model.

So your going to cut one? Do you have a CNC mill? Just an idea, when you have your final drawing, post over in the RFQ section and see how much it would cost to have someone make it for you on a 3d printer.

Looking good!

Didnt want to use a bitmap image background?

LOL.. i didnt know I could.. LOL

yes i have a mill, and im actually in the process of cutting one out now..

No, no buckle in hand, just going from picture...

I will be trying using the pic next.. uhm.. if someone can give me a GOOOD shove in the proper direction..

[mc-motorsports]

I'm still using Rhino 3.0 because if I upgrade, I also have to pay to upgrade RhinoCam, decided to leave good enough alone for now.

BUT,

Type in BackgroundBitMap
enter
P for place
select your picture
then either drag a window or choose the corner coordinates of the box that the picture will appear in.

There are a bunch of things you can do from here. What I would do is make the picture HUGE, trace it out with curves, lines, splines, what ever and when your done...
type BackgroundBitMap (again)
press V for Visable, this will hide the image
then scale your curves down to production size. By making the picture HUGE at first, when you scale it down, it will smooth out the lines, curves and splines... VS a small picture and having to scale it up, you can only expect it to get rougher.

Let us know how you make out. If I confused you, just let me know.

[kbillan]

I'm still using Rhino 3.0 because if I upgrade, I also have to pay to upgrade RhinoCam, decided to leave good enough alone for now.

BUT,

Type in BackgroundBitMap
enter
P for place
select your picture
then either drag a window or choose the corner coordinates of the box that the picture will appear in.

There are a bunch of things you can do from here. What I would do is make the picture HUGE, trace it out with curves, lines, splines, what ever and when your done...
type BackgroundBitMap (again)
press V for Visable, this will hide the image
then scale your curves down to production size. By making the picture HUGE at first, when you scale it down, it will smooth out the lines, curves and splines... VS a small picture and having to scale it up, you can only expect it to get rougher.

Let us know how you make out. If I confused you, just let me know.

I think im going to owe you more than one beer after all of this! LOL..

thats awesome. Next on the drawing board is doing it your way. Ill get started on it later this week.

thank you so much.

Keith

[chmillman]

What I would do is make the picture HUGE, trace it out with curves, lines, splines, what ever and when your done... By making the picture HUGE at first, when you scale it down, it will smooth out the lines, curves and splines...

I would not agree 100% with this. Certainly, you should make your image hi-res enough so that at the tracing size, the pixel are not huge squares.... But it's just a guide for your tracing, you don't need to make it humongously large.

The idea of tracing at a large scale and then scaling down to "smooth things out" doesn't work - what you want are good clean curves with the minimum number of control points and a good curvature graph if possible. Scaling the curves has no effect on smoothing, the control point structure is just scaled with it.

Creating smooth curves either from scratch or by tracing over something is a bit of an art form in Rhino that needs to be learned. The Rhino manual does have some tutorials for this IIRC... --ch