So you bit the bullet and jumped on the 3D printing bandwagon.
Good for you -- you're in for a treat as you explore a whole new world of creating and rapid prototyping. But as they say, "The first cut is the deepest" -- and getting started with 3D printing can come with a bit of a learning curve. Fortunately, Arrow Engineer and 3D printing aficionado Laura is here to get you started. Check out the video above to learn about building your first 3D design and some tips and trips for printing.
If you haven't yet looked into getting a 3D printer, check out this offering from LulzBot -- the Mini. With a self-level bed, compact size, and amazing accuracy for its price, this is a great place to get started.
As we do all of these technologies and all they give us, I thought it might be useful to take a step back and go through your first 3D print. We use Sketchup Make, which is a free downloadable program and the Lulzbot version of Kura, to generate the G code that the printer actually understands. When you open up Sketchup you’ll see something like this. You can zoom in and out using the scroll reel. By clicking the scroll real and dragging you can move things around. You can change the view by going up to camera> standard> top. Now we’re looking at it in two dimensions.
Let’s start by making a key chain. I’ll go over here to rectangle and it’ll tell me when I’ve hit the origin, which is really convenient. I’ll draw something and we can see in the corner that they’re some really bizarre dimensions. We can change it. Things are zoomed way in because SketchUp was designed to be used for house modeling and architectural stuff, so when we’re doing tiny little things, it’s going to zoom way in. That also means that it’s only accurate to about 1/16th of an inch so keep that in mind when you’re modeling.
There’s our nice little box. We want to put a hole in it. I want to make sure it’s exactly centered. I’m going to draw a line using the line tool from midpoint to midpoint. Now I could draw a hole or I use a high sided polygon because it just makes more sense to the printer and you have less chance of getting a lopsided circle. I’ll click it and drag it out and you can see in the lower right that I’ve already changed it to 12 sides. It’s a good number, sometimes it defaults to 8. You can change it as long as you haven’t clicked one yet. We’re going to go back to 12 and move that right on to our line somewhere.
We can start making one. You can define the inscribed radius. I’ll call it an 8th of an inch. You can measure that using the measuring tool, end point to end point and get 1/4th inch. The math works. To make that a hole, go up to the eraser. Erase the lines selecting the hole, right click the surface, and erase.
You can make this 3 dimensional at any time by using the extrude tool. What this does is allow you to push and pull surfaces. It’s very neat, however, it’s almost always easier to do all you can in one dimension and then extrude because it gets difficult to carve areas out of extruded surfaces. Let’s go back to the top and add some text to our key chain. Using the 3D text tool, you can enter anything you want. You have many font options. You can say height, how far you want it extruded, if you want it extruded at all. If it’s not filled you can’t extrude it and it’ll just be the outside of the letters. (DEMO)You can see that these are already extruded out for us about 1/16th of an inch.
We can round the corners. We will go in and round the edges. You go in and find two end points. Go in and make your loop as big as you’d like. We’ll go inside and do that for all four corners. If you want to make sure everything is symmetrical you’ll have to do the math.
Now we can extrude the entire thing. The text comes with us because it’s still glued to the surface. If we escape out of that and tell the heart to unglue, we lose the heart. It’s now just in place. We don’t want that so we’ll hit control z to glue it again. We can also unglue it and explode it so that each letter moves independently.
If you right click and erase it, you’ll see that it’s actually hollow. Don’t worry about this. As long as the all the sides are enclosed, Cara, the next program we’ll use will see this as a complete object. Let’s save it and It’ll save as a SketchUp model. You can’t just export this to a STL file on its own. You’ll have to go to Window in the extension warehouse for SketchUp. This is where you can download and install the STL generator from Sketchup. Search STL, click on it, and get the instructions for hooking up to SketchUp.
For some unknown reason, it will want to tell you that you’re measurements are in millimeters, when they are in inches. Just go with it. Don’t change or it will come up a really strange size. We’ll put it in a folder and then go open Cara. All you need to do is load your model file. It will tell you how long it will take to build it. I have support structure on. Because there’s nothing overhanging here, it can all be built from the platform that won’t change the time. If we were doing something else it could change it significantly.
This is on beginner settings. You can go into full setting, but honestly, we haven’t had anything good happen when we start changing these setting. Unless you really know what you’re doing, don’t mess with these, just stay in beginners mode. It works great.
Now all you need to do is save the G code. If you save the model, it will just save it as a model file. Save the actual code for the machine. Find the SD card that you’re using and save it on there. Then take the SD card to your printer, select print from SD card, find the model, and you’re on your way to your first print job.
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