How to build a 3D LEGO Model using LDraw (part 1)

In this tutorial we will build our first 3D LEGO model using LDraw. I will build it using two different programs based on the LDraw library - MLCAD and LeoCAD.

  • #43
  • 29 Oct 2013
  • 9:28

You can see video lessons Episode 40, for reference on how to setup LDraw on your computer. MLCAD is installed alongside the installation of the LDraw library. You could also visit the Ldraw Parts Tracker to look for the parts you need and also explore the LDraw library.

LeoCaD is a free CAD program for building 3D LEGO models. You could download the setup from here

Find the built models under the materials tab!

3D LEGO Model buildin with LDraw - first model

Download the archive with the models created in the video. My-first-model.ldr is the file created with MLCAD and My-first-model-2.ldr and My-first-model-2.lcd are the files created with LeoCaD.


In episode 40, we have set-up LDraw. So far, we can use LDView in order to open three models with using LDraw. We'll talk about building our own model. Well, in the next few minutes we'll build our first LDraw model and I'll show you how you can do this using different programs based on LDraw.

For the purpose of this tutorial, I want to build this simple 3D LEGO model. I'll build it using several different programs and leave you to decide which is the best for you. It consists only eight level parts, but is enough to see how one can join level parts using those programs. So, let's start building. MLCAD comes with the installation of LDraw, so I'll begin with it. First, we open the program and in the left you can see a group of parts and you can explore each group in order to find the frequent one. Or, another option is to look for the part. So, I'll begin with the Technic Beam, which we use for base of our model and its number is 64179. Okay, and here it comes. Next, we need Technic Beam long which is 6558. Okay, here it is. So, I'll put it. Now we need to rotate the pin along the Z-axis. So I turn it. Okay, and now all we need to do is to put the pin on the right place. Okay, great.

The cool thing is that MLCAD remembers the last orientation you have used. So now, we can put the next few beams without rotating them. Okay. So now, I have the four beams in place, and the next part is Technic Cross Block which is 48989. Okay. We take it and again we need to rotate it. First, along the Z-axis like this, and now along the X-axis like this. Right. So now again, I need to just position it. Okay, and take another one, position it here. And finally, we need to put the Technic Beam above all the parts which was 64179.

I take it. I have to rotate it along the X-axis.

Okay, and I position it both parts. Now, I'll save our project that will be "My-first-model". Save it on the desktop, and we are ready to open it. Okay, here it comes. You see, I have missed that one. The two parts are next to another. So, I'll go back to MLCAD and here I'll move this view up, and then move the parts above. So, now I can save it and load the model in the LDView. This program that we will use is LeoCAD. It's an MLCAD system based on LDraw and it can be freely downloaded from the Internet. You could find link for it under the material top, below this video. So, we again begin with the Technic Beam which is 64179. So, here it is. You can take it and position it on the screen. Let's choose more appropriate color like this one. So, I have to take bucket and color it. Okay. So, next we need the Technic Beam which was 6558. I'll take it and again I have to rotate it. Need to rotate it this way. No, it's not this way. It's along the, along this row, and it's on this axis. So, it must be this. As you can see, you can see how many degrees you have rotated part, which is kind of cool, so that you check whether it is the appropriate number of degrees or not. So, I'll rotate it to 270 degrees and then move the part to its place. So, it comes here. I need to move it a little bit upward and then put it back on place. So, great. Okay, so I'll need several more. One way is to move the parts and proceed the same way or can delete this one, take this, and copy and paste it. So now, I can just move it this way. Okay, again paste it, but this time move it here, and finally I have to move it to the upper corner. Great. Next, we need Technic Cross Block which is 48989. I'll take it. Again, we need to modificate it. So, we need to rotate it this way. Like this. Okay. So, need to rotate like this. Right. We align it to the block, and according to axis and copy, paste and then move it to its position. And, we need to put on top the Technic Beam which is 64179. Okay. So, I'll put it here. Move a little bit upward. Move it closer. So, a little bit more. Okay, and a little bit more this way and a little bit down. Okay, actually this beam isn't on its place, so I'll move it. Move it, so to this and I'll zoom to be more precise.

Okay. And, how do we save the program?

Again, on desktop but this time it will be "My-first-model-2" and we save it. This will be the end of the first part. In the next tutorial, I will show you how you can edit the files we have created using LD Design Pad in order to make it more precise, and afterwards using LPub, how to create PDF instructions for your model.