So I've been tweeting a lot tonight about OpenScad. I've talked about how it's different than a lot of other CAD programs because it's 100% code driven. To me that makes it easier to both use and learn from. I should probably put my money where my mouth is.
So I tried to pick something simple, and I went with how to make buttons for your shirt. My button will have 4 holes and be 1cm wide. You can easily scale this design to whatever size you want. I'll even talk about how to get one in your hand!!
What is a button. The first step in CAD I've found is to reduce objects down to a collection of shapes. A button, is just a cylinder with smaller cylinders taken out of it. So let's do that!
I'm going to start with making a button hole, this is where the thread goes through. Using the OpenScad Cheatsheet I quickly make a 2mm cylinder.
Using some delicious CopyPasta I'm going to copy & paste that cylinder 4 times. Here's were we get funky... I'm going to use translate to move each button around on the x/y axis; 2mm/2mm, -2mm/2mm, 2mm/-2mm, -2mm/-2mm repectively. Translate is a transformation function, they work to modify other shapes.
Note how I keep referring to "the button holes" as if they're 1 thing, but then in my code they're 4 unique things with 4 unique translations on them. I'm contradicting myself. Am I crazy? Clearly. So, let's remedy that with the union function. The union function is our first boolean type function. The boolean functions are for comparing/contrasting other objects. So in this case, union is going to let us group those button holes together. This will essentially make them one "thing". (In the extra credit section, I'm gunna show you an even cooler way to keep this going). Just to keep it exciting, I went ahead and added a -1 instead of 0 to the Z index of the translate, thus pulling my button holes below the horizon. Step 3 code.
Now that we've got the science of button holes sussed out, let's move on to the button itself. For this, I'm going to make a cylinder again, but I'm going to make it MUCH bigger, and I'm not going to translate it or move it around at all. It's just going to stay there.
Step 4 code.
At this point, assuming you're still reading and not going glassy eyed whilst bleeding from the ears due to the stroke my blathering has caused, you're beginning to wonder what's going on here. We have a 4 prong plug where @trollboy promised you a button. What's the deal? The deal, is the difference between the button and the holes. You see, difference is another boolean function in the same family as union. It takes the first object (my huge button cylinder), and then subtracts the second object ( The union of my collection of smaller button hole cylinders ).
Congrats. You designed a virtual button. That doesn't really help you put on your shirt now does it? No it does not. We need to turn this into a real button. For this, we go up to Design on the menu bar and hit Render [Alternatively hit the F6 key]. This will do all the real hard math to render your code into something printable, as opposed to the light weight preview you have been playing with. After that's done (it'll play a fun lil noise), you can hit Design again and this time hit 3D Print [Alternatively hit the F8 key].
This will bring up the 3D Print menu. If you've already ordered a 3D printer and are waiting for it in the mail like a mad man (know dem feels), or simply don't have one at all.. NEVER FEAR! Select Print-A-Thing and they will print your design for you and mail it to you. If you have a 3d Printer (I'm a fan of the Creality Ender 3, and @sexycyborg 's 3DPrintMill, which is also made by Creality) then you can use the OctoPrint button to pipe your design into OctoPrint for local printing.
So earlier I talked about another way to group items. As promised I'm telling you about it now. The secret is a module. A module allows you to turn your collection of shapes into your own custom OpenSCAD function. This is why I mentioned above that the Cheatsheet covers all the built in functions. There's a limitless number of functions/ modules you can make yourself, or download off the internet. Are you into Robotics? OpenScad links to an awesome MCAD library containing modules of bearings, gears, screws, servo motors, and the list goes on and on.
Extra Credit 1 Code.
Our button is pretty generic. I'll admit it. I mean I wouldn't wear it. As a friend told me; something something Drip is for life. So let's put a lil style on that button. How about a nice ridge around the outside? Well.. let's put on our CAD brains again.. a ridge is simply the middle carved away from a thing. SO.. I went ahead and turned the whole button into a module like we learned in the previous step, and then I used difference to remove the smaller cylinder I made after using translate to move it up as to only overlap the top bit.
So I realize I zoomed through this howto. This is the problem people who know a thing have when explaining the thing to people unfamiliar with the thing. You make a bunch of assumptions on what should be obvious, and skip over huge swaths. I sorta suck that way. At the top of this page, there's an issues link, alternatively you can click here. If there's something you don't understand, lemme know and I'll make adjustments. Feeling spicy? Feel free to check out this repo, make your own changes and submit a pull request! I AM HERE FOR IT!