Creating Rounded Objects

One thing I quickly learned (and I'm constantly relearning) is that something that seems easy usually isn't. Among these is anything with a rounded surface. Keep in mind that Sketchup is designed as an architectural program, so its focus is primarily on hard surfaces and angles.

Making a basic round shape, such a cylinder, is very easy. Simply draw a circle, then use the extrude tool to give it volume:





This is great if you're making the land of smoke stacks, but what if you need to have a dome or bowl shape? Sketchup uses a lathe system. First, Make a 2d representation of what you want your rounded surface to look like. Then place a circle underneath it that will be the diameter of the finished product:



You can do this by using the Arc tool:


Then highlight the area beneath it that you want it to follow, pick the Follow Me and select the 2d surface:







And now we have a domed surface on top of our cylinder!

You can also create more intricate patterns by first making a flat surface, and then creating the design you wanted using the Line and Arc tool. It helps to make certain that the design area is only half of the circle that you will be using:





Then delete anything you don't need:



Finally, use the Follow Me tool to make the shape:



Just delete the circle if you don't need it anymore and you'll have your new, rounded surface ready to go.

Using the Tools on Surface plugin, you can directly manipulate the rounded surfaces. I'll get more into that on the next post.

Happy modeling!

Modeling Update

I know I said I would make a tutorial for creating round models. However, I've run into a few problems with the project I am currently working on, and though I would share some cliff notes on it.

I noticed a bit of a size problem with my boltguns. Mainly, they're taller than marines with the combi-attachment. Now, I wanted them larger, but not quite that large, so I'm in the process of shrinking them. Here are some of my thoughts and photos to detail the changes:

The bolter was shortened substantially. The flamer was also shortened, including the gas lines. The promethium canister was in the way of the marine's hand, so I angled it downwards.




The melta-gun had its receiver shortened and the fuel canister moved back a bit. This was the second most annoying move, and the receiver didn't cut evenly, but now I know how to cut it very quickly and efficiently. I'll definitely be putting that in a future post.



My last work is the plasma gun, but it is the most difficult because of all the angles. It is still not quite finished and needs polishing. It also remains the largest of the combi-weapons. It should be, however, as it is generally the most expensive, and the only combi-weapon that can shoot twice according to the rules.



Stay tuned for more!

Pitfalls of 3d Design

There are several things to be aware of when you're trying to design a model for 3d printing. They are:

Manifold Edges
Surface Facing
Material Thickness
Material Optimization

Manifold edges are probably what people struggle with the most when they start out. It's a big, scary word that actually doesn't mean very much.

It's basically saying that all the edges of a model must be connected. Imagine you have a box. The box must be connected on all sides in order to hold liquid, right? Something like this would be NON-MANIFOLD:



The edges aren't connected, so the the computer (and therefore the printer) cannot build the shape. Now, this is an obvious example. Lets look at one that is less obvious:



Now, you may be asking what's wrong with this. After all it's an open box, right? Well, not exactly. See, a line and surface has 0 thickness. That is, it doesn't actually exist. The computer is simply telling you that you're working with a surface this size - but the surface has no thickness yet.

In the real world, everything has a thickness. Even paper and atoms can be measured, so we have to make the same true of our models. Lets give our box a thickness:



Alright, now our box has thickness. It's ready to print, right? No. Now we address the second problem. 3d printers need to know what surface is on the outside and which is on the inside. You'll notice the box has a blue-grey color and a white color. The blue-gray marks the interior of an object, and white the outside of it.

The rule of thumb is to make certain everything on the outside is white:



Alright, now this box is 100% 3d printable!

But, if you were to put it up on the market, it would probably cost around $10,000. Why? Material thickness. Shapeways charges by the amount of material required to print the model. For this reason, you'll need to make certain that your model is A) The size you want it to be and B)hollowed out (material optimization).

I'm not going to get into hollowing models because that is a full post on its own.

But let's discuss material thickness. Each material has a minimum thickness. If the material is too thin, it will break when it is cleaned or during shipping. Don't worry, Shapeways will detect the problem and reject your model so you don't waste money. But it won't tell you where the problem with thickness is.

There are a lot of different materials, and I won't go into them all right now. You can find this list (along with a lot of other helpful tips) here.

A plugin that is extremely helpful is the solid inspector. This plugin will scan your models for breaks in the surface and a few other problems and highlight them. This can save you a lot of time, especially if Shapeways is consistently rejecting your model.

Stay tuned for my next entry, where I'll explain how to make rounded surfaces!

Additional Information

People have been asking me about 3d printing and how to get started. Luckily, it's both cheap and easy to get started in 3d modeling, but there are a few things you will need.

First, you'll need a 3d modeling program. If you are new to 3d modeling, I highly recommend Google Sketchup. It's both free and very easy to learn. You can download version 8 here. Another free option is Blender, though it has a much steeper learning curve and a lot of tools that are unnecessary for 3d printing, such as lighting, rendering, animation, etc. However, it is much better at creating organic models.

Organic models are humanoid shapes, odd faces (such as hands tree trunks and the like). While Sketchup is capable of creating them, it was not meant for nor does it facilitate their creation.

You can learn more about Blender here.

Other paid options include Rhino, Maya and AutoCAD. These tend to be very expensive ($300 to $1000 dollars) and also have a bit of a learning curve. I generally recommend these to people who have spent time with Sketchup to learn the basics and decide if you want to continue working with 3d models before dropping a large sum of cash.

Second, you will need plugins. Sketchup can export to .dae, which 3d printing natively supports. However, there are a number of tools that will make your life much easier, especially when working with rounded surfaces.

You can begin by registering at Sketchucation. This is fast and free, and allows you to download several powerful tools. Once you've registered, click on Plugins Index to view the available plugins.

I know, it's a lot to take in at first. Don't worry, there are only a few you need to start with.

A lot of plugins rely on the Fredo library, so make certain to install that first.

Solid Inspecter to check for problems that will prevent 3d printing.

An additional list of very powerful tools can be found here (make certain to sign in so you can see the animations describing how the tools work).

To install the plugins, simply unzip the contents to your sketchup/plugins folder. This is typically found at C:\Program Files (x86)\Google\Google SketchUp 8.

Make certain Sketchup isn't running when you install the plugins. If it is, don't sweat it, just restart Sketchup and you should be good to go. Your plugin folder should look something like this:



Now that your plugins are all installed, you're ready to start modeling! Tune in tomorrow. I'll be posting the do's and don'ts of modeling for 3d printers.

First Post

Ah, so here we go, a blog. Where to begin? Maybe I should start with my intentions.

Keep in mind, I am not an artist, not in the least sense of the word. I make horrible stick figures and scraped by my high school drawing class with a D+. But, I was rather taken recently by the prospect of 3d modelling. Interestingly enough, 3d modelling is not a normal medium like oil or charcoal. No, it is its own, unique form of art.

Those of you interested in it might rejoice in the fact that it does not require great artistic talent to master. At least, not that I have seen so far.

Also let it be known that I have taken no classes or made any studies in the field of 3d art or animation. Everything in this blog will be from my own trial and error, and perhaps, a way for you to avoid the same pitfalls. I do not assume to be a master, expert, or even journeyman in such things. But maybe that is for the better. There are more students than teachers, and there is something to be said for group learning.

As a brief history: I started playing with Google Sketchup (v8) in mid-December. My objective - to design a 6mm scale tank (roughly the size of a quarter)for 3d printing by a company called Shapeways. After a few hours of trial and error, I had something that looked like a tank:



I promptly uploaded it to Shapeways, where their automated system promptly laughed me off the internet. See, it's not enough to simply make a 3d model. Printers are very expectant machines. They expect to know where to begin and where to stop. What is on the outside, and what is on the inside. Where one object begins and another ends.

Being only vaguely aware of such things, I started googling anything and everything I could about 3d printing. Finally, I figured out exactly how the model should be put together. But I didn't feel like continuing on my tank yet. I felt I needed to start smaller, with a basic structure that already exists.

So, I started playing with a bolter from Warhammer 40k (a 28mm scale strategy game). I decided I needed to do 2 things. The first, was make a base model to drive all others from. This would have the same dimensions as a normal bolter,so I could add or remove additional features without worrying if the bolter would fit the model it was meant to go with (Space Marines):



Bummer. With that in mind, I decided on
With my base model completed, I decided to make a larger, more "assault rifle" version. I increased overall size by around 40% and and removed the front sight aperture in favor of the holographic sight. I also decided to incorporate combi-weapons, the 40k equivalent of under mounted weapons:



The problem? Well, it was too big:



Bummer. So it was back to the drawing board. I decided that I would decrease the size so it was only about 20% larger, and add modular optics, combi-weapons, and magazines. This way there would be much more customization:



It looked better, but there are still size problems. I'll introduce those in my next post.

The second thing I realized I needed to do, was begin making a component library. In Sketchup, a component is an object or objects that are generally considered finished. You can copy components out of the library and right into the workspace. In this way, I could make a base scope mount. Every time I make a new scope, I just copy the mount in and start working, then save the new scope as a different component.

Because I can very rapidly build from a base model or interlocking component, I'm able to add much more variety to my models than would be possible through conventional modelling. At least, in the span of time it takes me.

The downside is that any changes to the base model will require changes to the components. For example, if the top of the bolter were to become wider, the scope mount would have to be changed to match.

Making modular systems requires a lot of pre-planning so you don't end up doing the same work several times, something I've been learning the hard way and will share in a future blog entry (you're going to notice a pattern here).

So, stay tuned. I have some interesting things planned for the future.