Introduction

So like I said, in this tutorial you will learn how to model a light bulb in Rhino. The first “glass” part will be just a bit tricky because we need to control the curves little bit more than usual. After that we will make bulb screw threads, where the method is similar if not the same as the one explained on Rhino tips website. If only I known for it when I made this tutorial heh. Anyway, this one is pretty easy, but needs some special attention in some parts.

If you like, you can download source 3dm files step by step just to keep on the track.

source 3dm files step by step

This is what you will have in the end:

final model

STEP 1

First we will start from top to bottom. So we’re making the lighting spiral. Start with creating Circle from top view of radius 5cm. And create two small circles of radius 1cm. You can use Snap to make them really easy:

image 1

Next, we need a Spiral. Using Spiral command make one starting from origin. Once you start the Spiral command just input 0 (zero) and press enter, now from Front viewport make it high 5cm. And for the radius use your already made circle that is 5cm in radius. Move that spiral 3cm up from front viewport and you should get something like on the image 2 and image 3.

image 2

image 3

Now we need a little help line. You can make one starting from center of the right smaller circle. It should be straight vertical line, so you can finish it either from front or right viewport:

image 4

Now, using BlendCrv blend the lower end of spiral to the little help line with G1 continuity on both sides:

image 5

Using Copy command, copy the spiral and blended curve. While in the Copy command in the command line click on InPlace option. Or simply use Copy & Paste commands (ctrl+c, ctrl+v). While having selected two copied curves, Rotate them from top viewport by 180 degrees. Check if you have something like on the image 6:

image 6

Now, with create a Point from right viewport (or front would work fine too) exactly 9cm from origin:

image 7

Now, start Extend command, and press enter for dynamic extend. Enable OSnap and check Point option, and click on each upper end of spiral and extend it to the point.

image 8

Now the endings of two spirals are not tangent. So with Match command we will match those two curves. Make sure both ends are set to Tangency and Average Curves is checked:

image 9

Now select all 4 parts of 2 spirals and join them together. Now, using Pipe command we will make a surface out of this curve. For the starting and ending radius you can use two small circles as reference. Near OSnap option is a good way for this. Ofcourse, you could use sweep1 or even sweep2 commands.

image 10

Now the big circle will be used to create the body of our bulb. Select it and run ExtrudeCrv command. Make sure the Cap is set to Yes and BothSides to No. We will extrude it down by 8cm, so you can either use snap and count for yourself, or simply input in the command line -8 and press enter.

image 11

Using FilletEdge command fillet the upper edge of the cilinder by 0.5cm.

image 12

Using one of two smaller circles offset one by 0.3cm. And move it up vertically by 0.6cm.

image 13

Using Rib command and the body of the bulb create a surface like on the image 14. Rib distance is 0.2:

image 14 - mirrored curve for rib

Now for the ribs, we can make them look even prettier by filleting edges. So with FilletEdge command fillet those three edges for each rib with 0.05cm as radius:

image 15 - filleting

Now lets get back to the lower part of the bulb body. Like we filleted upper edge, we will chamfer the lower one with ChamferEdge command using 2cm as CurrentChamferDistance option.

image 16 - chamferedge

Now, we will FilletEdge the middle edge with 0.5cm as fillet radius.

image 17 - filletedge radius 0.5cm

Using ExtractSrf command we will extract the bottom cap surface:

image 18 - omg, we're using ExtractSrf for the first time

When you extract this surface, you can delete it. And using the edge where this surface was extrude it by 1cm down. So just input in command line when extruding -0.5. Make sure the Cap option is set to No.

image 19

Now, you can create PlanarSrf to “cap” it on one side: (you could also join all the upper surfaces of this bulb body and simply use Cap command to close it)

image 20

Lets do some details on the body. From front viewport create one line and offset it down by 0.3cm… Like on the image 21

image 21

With Trim command trim the body surface between two lines:

image 22

Using Offset command, offset the two edges inwards by 0.2cm. The easiest way is to first have everything deselected and run the command offset, then click on one edge from perspective view, and then from top viewport simply move your mouse pointer inside the cilinder and in command line type in 0.2 and press enter. Do the same for the other edge and you are set to go.

Then, using Loft command click on the lower edge first, then two offset circles inside, and then the upper edge, and with style set to Straight sections create loft:

image 23

Now, join those surface, and make it prettier with FilletEdge using 0.05cm as radius.

image 24 - smooth edges with FilletEdge

Resources

Blueprints (required registration, but I think it is worth!)

STEP 1

Again, in this tutorial I have also skipped the blueprints setup.

First, create 3 outline curves in Front viewport with InterpCrv and bridge two upper with one line using polyline (good to have osnap Near option turned on)

Next, split those two bridged curves with that created line (bridge).

Create using InterpCrv outline for the handle section, and offset by 1 inside.

Trim the two curves and split outline curves.

Then, from right viewport, create three lines, and Fillet the corners with 1 unit. Offset that curve by 1 unit inside, and you will create another instance of this curve, but this one won’t have filleted corners.

Extrude those two curves and trim two newly created surfaces with the curves in Front viewport.

The two curves for handle section need to be positioned on the center of your base surfaces. I’ve done that by first creating the surface with Surface from 3 or 4 Corner Points command (SrfPt) and I positioned that surface on the middle of my model. I’ll use that surface for future centerings (I hide it when not needed).

When you moved those two curves to the center, extrude them according to image below:

Here, I’ve used BothSides option in Extrude command. Notice the Top viewport to see the extrusion distance.

Blend the edges of coresponding surfaces, check image below for reference…

Connect blend curves with lines on the mid

Using Network Surface command create surface out of two blend curves and one line.

Do this step for 3 other parts, and join the surfaces. Next, we need to blend the inner and outer surface… I used 0.5 for both sides blend bulge.

In the picture above you can see that I didn’t use blend for connecting the two network surfaces, instead I used Sweep2. Do that 3 more times for other surfaces.

And for the little 3 curved surface corners I used Sweep1: