# Modeling light bulb

In this modeling tutorial you will be shown how to model a light bulb. This is english version of my tutorial, if you run on the video of my croatian version, its cool.

### 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 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 . Using command make one starting from origin. Once you start the 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. 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 blend the lower end of spiral to the little help line with G1 continuity on both sides:

image 5

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

image 6

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

image 7

Now, start 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 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 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 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 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 command and the body of the bulb create a surface like on the image 14. 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 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 command we will extract the bottom cap surface:

image 18 – omg, we’re using ExtractSrf for the first time ðŸ˜€

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 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 command trim the body surface between two lines:

image 22

Using 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 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

Pages: 1 2 3

used 34 commands

### 13 Responses to “Modeling light bulb”

1. […] this tutorial, naturally, you will need a model of a bulb. So, you should first read and complete Modeling light bulb tutorial and create yourself a model. Oh, you’ve done it already? No you actually just took […]

i am having difficulties making a union between the sweeped coil for the threading and the body. do you know why that is?
i just get the message ‘boolean union failed.’

3. Ivan says:

go see image 44-move. You could try extending the two ends of the V curve, and moving it a bit more like on the image. That should fix it.
if you still have problems, please post your image and/or model in the forums under this tutorial and I will help you more.

4. Ever says:

I am having the same problem with the boolean union, it just fails. There is a step I really don’t get and is precisely in the image 44, before that you had a triangle with filleted edge and after that there’s no filleted edge

5. Ivan says:

yes, you are right. Image 44 shows filleted curve, and the move image (img45) doesn’t. If you look at the img46 you will see that one has filleted corner. It is just an error in the image.
But I understand you are having problems, maybe that wasn’t explained the best way, but basically you need to have your section filleted curve positioned perpendicular to the spiral, and with trial and error you should position the curve so when you do sweep1 command you get the surface right. Meaning, it goes through the surface bottom “cap” so you can do boolean union without problems.
I might record a video of this step, it might get a bit clearer. But the important thing is you need to do this by trial and error.

6. Dioniso says:

Great tutorial, although I couldn’t do the FilletEdge of 0.1cm like image 47. I tried everything but it didn’t workout…

About the boolean union problem, just put the section (“little triangle”) on the start of the spiral burt and a move a little bit inside, to the interior (make sure your middle point is not over the end of the line) . You will get a very tiny intersection between the bulb surface and the spiral which will enable the boolean union…

7. Ben says:

What an excellent tutorial, I am so pleased i came across your Web site,
You have chosen great models to be able to cover so many techniques, and commands
Also thank you for answering peoples problems, It really help’s in solving those issue’s we have along the way

keep looking up cheers Ben

8. Perfect tutorial !
Its my first tutorial in Rhino demo ðŸ™‚
Im a MoI 3D user so its pretty easy to follow
Auxpecker plugin is amazing, this thing should be in every 3D modelling application by default !

9. Norman says:

Hi, i wasn’t able to execute the rib command. Can you please explain more specifically? Thanks a lot!!

10. Bartjan says:

Thanks for the tutorial!! It was a great help.

– Bartjan

11. […] light bulb model was done in Moment of Inspiration 3D using a Rhinoceros 3D tutorial located here It was done in both software for comparaison purposes. Check the other tutorials on the same […]

12. pontif says:

Thanks for that very instructive tutorial.

13. Leon says:

The BooleanUnion as shown in IMG46 always fails. I’ve tried everything. It’s impossible and I don’t understand why. So frustrating …