Messages

1

Ask for help / Re: How to set up commands on middle mouse button?

« on: June 19, 2011, 03:39:13 PM »

Many thanks.  After working with it, I found the following direct method for copying command icons from one toolbar to another. 

The Help explanation is unduly complicated by the terms "parent" and "child," which must mean something to the programmer but not to me.  The idea seems to be that you copy a command icon from its present toolbar to a different tool bar.  The copy of the command icon then becomes a link back to the original.  The process is called "create a link" and this is how it is listed in the Help menu. 

Anyway, this worked well:

1. Open the parent toolbar that will contain the link button.
2. Open the child toolbar that will be linked to it.
3. Press and hold the Ctrl key.
4. With the right mouse button down, drag a button from the child toolbar to the parent toolbar.
A copy of the button appears in the parent toolbar with the white triangle link symbol in its corner.

It is very helpful to have handy commands like Mirror or Extrude, which are nested out of sight inside other command menus, instantly accessible on the middle click menu. 

John

2

Ask for help / How to set up commands on middle mouse button?

« on: June 07, 2011, 07:15:51 PM »

In class, we were shown a trick I am trying to repeat, but I can't seem to make it happen.  If you click the middle mouse button (or the roller) a little popup menu appears at the cursor point. 

On the popup menu are a few handy icons, maybe 6 commands.  The idea is to save waste motion by putting your most commonly used commands in a quickly accessible cluster. 

The instructor had a trick for loading other useful command icons onto this little popup menu.  For example, he had put the mirror command in there.  But how did he do it?

If you right click on the top of the popup menu, it will give you some options, including "Add a button," and I tried this.  The button is blank. 

In short, how do you copy command icons into this little "middle click" popup menu? 

Thank you for your insights.

John

3

Ask for help / Re: How do you make nuts and bolts, worm drives, screw threads...?

« on: January 25, 2011, 02:36:16 PM »

Here is a series of screen captures to illustrate one method for thread cutting. It is based on watching YouTube videos of thread cutting operations as carried out on machine lathes.

 The illustrations labeled "before Boolean" and "threads & blank" show what I was working toward in Rhino. 

I am thinking of the lathe cutting tool as a sort of paintbrush that leaves behind a V-surface that follows the path of a helix.  At the shaft end of the helix, as the cutting tool retracts, the radius of the helix expands into a spiral.  You may need to scroll these images to the right to see the part of the thread where it spirals out from the diameter of the basic helix.

 Once the spiral and helix are formed and joined (Using Spiral and Helix in Rhino), a thread profile is pinned to the beginning of the helix.  This is then transformed into the V-surface using RailRevolve.

The front of the blank is beveled at 45 degrees.  Also notice that the thread profile has been extended (with Extend), so that the depth of the "V" is exaggerated.  This is because the Boolean operation, to follow, works better if there is a good overlap between the spiral surface and the surface of the machined blank. 

The example used here is a model of a component used in a 19th century steamship. 

John

4

Ask for help / Re: How do you make nuts and bolts, worm drives, screw threads...?

« on: January 23, 2011, 04:39:55 AM »

Thank you Ivan, the tutorial is very helpful.  I have also found it helpful to watch videos of actual thread cutting operations on lathes.  Here is an example:

http://www.youtube.com/watch?v=0q_q53wsyHU&feature=related

Notice the way the blank cylinder has been prepared with a 45-degree face at the beginning and end of the screw thread.   My thought is to replicate the blank in Rhino3D as a first step, and then do a Boolean using a separately formed thread pattern created with Helix and Spiral. We'll see.  Thank  you again. John.

5

Ask for help / How do you make nuts and bolts, worm drives, screw threads...?

« on: January 12, 2011, 07:58:32 AM »

Cutting threads is a common problem but it is difficult to search for solutions, since the word "thread" is such a common term of art on the internet.  I found four links about it, here, but I confess I can't make much sense out of them:

http://www.rhino3dhelp.com/forum/index.php?topic=433.msg1451#msg1451

http://offbroadway.blogspot.com/2007/01/internal-screw-thread.html

http://offbroadway.blogspot.com/2007/01/screw-thread-tutorial.html

http://offbroadway.blogspot.com/2006/12/screw-thread-tutorial-1-draw-shape-of.html

Is there a Rhino3D plug-in that draws nuts and bolts and screw threads? 

So far, using RailRevolve and a simple thread profile, I have been able to draw a helical thing that looks like a thread.  However it does not have a proper beginning and end, and I cannot seem to integrate it with a cylinder representing a bolt. 

Many thanks for your insights or links.

John

6

Ask for help / Re: Lost my template files...

« on: June 09, 2009, 07:50:26 PM »

It turned out to be a deeper problem, the Help file was also gone.  I re-installed the program, so everything is ok now. 

It would be useful to know, anyway, the names and directory of those templates.  Best, John

7

Ask for help / Lost my template files...

« on: June 09, 2009, 04:56:31 PM »

When you open a "New" file, Rhino asks you to name a template.  The names are on the order of "Large object, feet" or "small object, millimeters."

For some reason my template files disappeared today.  I make regular file backups, so they are still on my system, but I don't know the filenames.  They are all just .3dm suffix files, I think. 

Don't know how I did this.  I have just installed a demo of a raster to vector program, and I did some uninstalls along the way, so maybe I inadvertently uninstalled the templates, tho this seems unlikely.

Does anyone happen to know the full names of the template files? Or the directory in which they are kept?

Many thanks for your insights,


John

8

Ask for help / Re: frustration with Fillet Surface command

« on: May 12, 2009, 05:00:53 PM »

Yes, I agree -- Ivan is a genius. I would be lost around here without his explanations and clear cut demonstrations. 

Thank you for your counsel on this -- the PIPE techique solves a persistant problem. 

Best, John

As a post script, I should mention that I figured out why the parts and pieces dissapear when I use Render.  It is just the they are flipped inside for outside. I corrected this with the FLIP command, and the missing pieces reappeared. 

9

Ask for help / frustration with Fillet Surface command

« on: May 12, 2009, 09:19:20 AM »

On a model I am working on, the Fillet Surface command keeps producing unpredictable results. In order to familiarize myself with the command, I made a simple system with two extruded circles.  The circles are each a single closed curve, so there there should be no surprises in the curve itself, nor the surfaces. 

I tried to simplify the situation by using each surface to trim the other, so that the intersecting surfaces are well defined -- not ambiguous.

Here is an example of the results I get.  Check the screen grabs.

The front fillet is okay, nicely made, and a continuous surface that forms a fillet all the way around the circumference of the tube. 

The back fillet is somehow segmented -- not into half fillets, as sometimes happens.  There is one half-fillet, plus two quarter-fillets.  One of the quarter fillets is selected. 

The fillets appear okay in the Shaded or Ghosted view.  But when I go to Render, the surface disintegrates into holes and islands.  A very odd business.

Bear in mind that the curves  I used to extrude the original surfaces were just circles.  Pure, closed, 1-curve, unexplodable circles. 

Is Fillet Surface just a cranky command? Or have I somehow set it up wrong?  I have Trim set to Yes, and Extend set to No. How do you set yours? 

Many thanks for your insights.


 

10

Rapid prototyping and CAM / CNC machining of plastic

« on: May 11, 2009, 02:50:21 PM »

There is a service at

www.firstcut.com

that will machine parts from plastic using CNC.  The company is part of ProtoMold.

They will quote in a day, nominally, but they seem to be most at home in Solidworks. 

I sent them a component in a ACIS file (suffix is .sat) exported from a Rhino 3dm file. 

They reported back that it is an "assembly" of parts.  In fact it is one single part, but it is made up of several objects. 

Has anyone encounterd this?  In other words: How would I make my "assembly" look like one part -- which it is -- to their system?

Or.  Is there a CNC vendor that knows Rhino and works from Rhino files directly? I really like the idea of working with machined parts.

Many thanks for your insights.

John

11

Ask for help / Re: Odd little bowtie pattern

« on: April 30, 2009, 05:16:01 PM »

Dynamite.  Many thanks.  The setting as found was zero. At .01, the bow tie was still apparent.  At a setting of .001, it disappeared.   

Where in the world did you learn this?  Is there an article somewhere on mesh settings that I could read?  To be candid, I have no idea what a mesh setting might be. 

Thanks again, 

John

12

Ask for help / Mystery menu. Where is it?

« on: April 21, 2009, 12:44:53 PM »

Here is a puzzle. The menu shown here is extracted from the third panel in this helpful tutorial:

http://www.aversis.be/tutorials/rhinoceros/rhino_ashtray_04.htm

The idea is to Render a shaded object, and the menu shows two pushbuttons: one for "Metallic," the other for "Plastic." 

I think this is a great choice, and I would like to use it.  I am working on a project with both metal and plastic parts.  However, I cannot find this menu in Rhino 4.0.  It is possibly a Rhino 3 menu?  Is it in Flamingo?

Whether the menu is there or not in 4.0, how would I set up RhinoRender to produce 1) plastic or 2) metal?

Many thanks for your insights.

John
 

13

Ask for help / Re: Odd little bowtie pattern

« on: April 16, 2009, 09:52:45 AM »

Thank you for this study.   

The image is Rhino'd  from drawings that appeared in a patent issued in the early 80s. I am obliged to faithfully replicate the original drafting work. I think whoever drew this contraption used a parallel bar and circle stencils, so it is mostly composed from straight lines and simple arcs.  I have used SimplifyCrv to get this look in Rhino.

I had to keep going on the project.  Since the "Cap" feature is implicated in the bow tie artifact, I worked around it.  I drew the structure as an extruded ribbon, and then used DupBorder to capture the edge curves.  I then made side plates as planes from these planar edge curves. 

My impression is still that "Cap," when used in combination with curves that have been treated with "SimplifyCrv" -- somehow produces the curious bow tie effect.

14

Ask for help / It has something to do with capping

« on: April 15, 2009, 05:15:48 PM »

Some progress.  If I don't close the curve, and extrude it as a long ribbon, no bizarre little bowtie appears. (See screen grab.)  The shape of the ribbon's surface is fine. It is an open structure, however, and cannot be capped. 

Maybe the "cap" option, in the Extrude command, has something to do with this.

I haven't changed the curve, I simply left it open. 

Could this be one of those trimmed surface vs untrimmed surface things? 

Anyway, I need those caps.  As a workaround I could use two planes? But I would rather understand what is happening here, and how to fix it properly.

Many thanks for your thoughts. 

 

15

Ask for help / Odd little bowtie pattern

« on: April 14, 2009, 06:48:42 PM »

This is a frame made by extruding a curve on both sides, and capping.  The curve was simplified with SimplifyCrv before extruding.

At two of the bends, this curious bowtie pattern appears. The curve should be a simple (not compound curved or kinked) surface. How would I get rid of these bow tie pattern? 

Thank you for your insights.

John

ps.  The second shot shows the Zebra analysis.  Strange that one line, extruded both ways from the centerline, could impart this variation in shaping to an extruded surface.