As you might notice, all these tutorials are pretty much the same. This is the method I use, and find very good. First, make the shape of the model, and then cut the details.

Well, this time we I won’t be showing you how to set the reference images in the background, as I think you have learned that from previous tutorials (I’ll add in tips & tricks section how to insert these, for future reference).

RESOURCES

STEP 1

We’ll make a rough outline trace for the speaker from Front viewport. Using polyline create 4 lines and position them using rotate like on the image below:

Then, using Trim command, trim off the parts we don’t need, so we have a closed curve. Fillet the left upper and lower edges with 12 units (I have set the resource image width to 83 units, just for the aspect ratio reference).

From top viewport, adjust the closed curve so it matches the angle as on the reference background.

Next, from the upper left corner (in top viewport) make a straight line 80 units in length. Using PointsOn turn on the control points for the closed curve, and using RemoveKnot command, remove two outer fillet knots on each round part.

And mirror that closed curve using this straight line’s mid point and Ortho option.

Using these two closed curves, create a surface with Loft command.

Close the objects both left and right sides with planar surface command (PlanarSrf) and join those three surfaces in one object.

Next, we need to make the back side curvy, so lets create a curve with Interpolated points (InterpCrv) like on the image:

Extrude the line (you can use Bothsides option to make sure it goes outside your object). Also, you will probably have to adjust the direction of extrusion, and you can do that by clicking on Direction option of Extrude command.

Trim off the parts of both extruded surface, and that object. After that, join the object.

Now, we will create a curve for splitting the base model. We are using the same method as for creating the rough outline trace as on the beginning of this tutorial…

We do this step again for top curve:

Using filletedge command fillet the two edges where our new curvy surface touches the flat surfaces.

From frot viewport, project the curve on the base model. You should get this:

Do the same for the top curve, but Project the curve on the object from Top viewport.

Copy the main object with Copy command, and paste it with Paste command (CTRL+C and CTRL+V works here). It is better to first copy, then trim the base object with one (either top or front curve) then paste that copied object and do the trimming with other (if you first trimmed with front curve, then now trim with top curve) curve.

Using earlier projected curves we will create cross sections between them with polyline command.

Mid and Perp options in Osnap toolbar are very helpful here. Near option is also needed here. Proceed with creating cross section lines until you get something like this (please not those lines need to be perpendicular to the curves).

Using sweep 2 rails (sweep2) command and set the yellow two curves from upper image as two rails, and other lines as cross sections. And tick the Closed Sweep option.

Unhide all the other parts, and join this surface with other two.

Now, you can explode that as we will be offsetting (offsetsrf – I have offset by 0.5 units) the main two surfaces and we’ll again create the cross section…

Using Duplicate border on the offset surfaces create the rail curves.

This is the same way of creating the object as few steps before, but this one is by 0.5 units smaller. I believe we could simply scale down the bigger part, but hey, this is me, and I’m making this…

Ok, so we made an alternative to non-existing shell command in Rhino3D v4 (rumor is that in v5 there will be shell command-yey!).

Yeah, yeah, I know. You must be thinking “Another rim tutorial”. Well, first of all, I’m pretty sure you will learn even one new command in this tutorial.

Resources

Video tutorial  for modeling car rim.

STEP 1

Insert the first reference image into the background of your Right Viewport. I made it 50 grids wide. You can set the background image to be in color, and remove grid with grid command. Using polyline (or just line) command, make simple straight lines according to the background image.

Trim the parts that aren’t needed, and fillet the intersections with the radius of 2. And offset by 0.4 inside.

After you made a profile for the rim, insert second reference image and using scale background image and move background image commands, position it so it somehow fits your profile curve.

Using Curve: Interpolate points command, create another profile… like on the image below. You can create one polyline in the middle of the rim.

Trim off the parts of curves you don’t need, and on the inner side of your spoke, fillet the straight line and curve with 2.

NOTE: at this point, I have rotated my curves from front view by 90 degree and positioned so the far right end of curve is in origin (0,0)

Using Remove Knot command, remove selected knots. So you end up with uninterrupted curve, so when you try to explode it, it says this: “Cannot explode single curve segments.”