Sketch-Up Project Gear by Mark Slagle

Transcription

1 Sketch-Up Project Gear by Mark Slagle This lesson was donated by Mark Slagle and is to be used free for education. For this Lesson, we are going to produce a gear in Sketch-Up. The project is pretty easy but uses a combination of commands to produce something quickly, that would normally take a long time. Here is a picture of the gear that we are going to make: To start, take the circle command and draw a circle on the page like below. Don t worry about how big it is; just make it look like the picture.

2 Also, while you are there, go ahead and erase the figure in the picture. Next, you are going to be drawing a series of lines that are RADIAL to the circle [that means they are going to run from the center {or vortex} of the circle, to the outside perimeter]. Start by drawing the lines from the middle out to the edge and draw them on the red and green axis.

3 Take your time and you will have four lines drawn. Notice that the lines you drew on the solid red and green axis don t show up too well. Don t worry about it, they are there! Next you are going to draw lines between the ones you have already done. This is called DISSECTING AN ANGLE. The way you do it is to start in the middle and drag the cursor to the edge somewhere in the middle of the other lines. When you do this, it will say midpoint. I ll do a few and show you below:

4 Do you see where it says Midpoint in tiny letters and has a little blue dot? That is how you know you have exactly dissected an angle! Now, just continue doing that same thing until you have all four of the shapes that look like pie pieces divided in half. It should look like the picture below:

5 The next step is to divide these pie pieces even further! Take your time; zoom in and out if you have to; and remember to look for the little blue dot that says Midpoint. Now, you re going to divide them ONE MORE TIME! Again, take your time and zoom in and out if you need to. Remember, you can also rotate, if needed. Does it look like the picture below?

6 I made the picture above a little bigger because I wanted you to see all of the lines. Notice that while you are drawing the lines, sometimes a line will turn pink. That means that you are drawing a line that is PARALLEL {what does that mean?} with the line behind it and also COLINEAR {this means that the two lines really make one long line}. Now the next step is to draw another circle, this time starting in the middle of the circle you have drawn and going out until it is almost to the edge of the first circle. It should look like the picture below:

7 It doesn t have to be exact, just make it look pretty much like this. The next thing you have to do is erase all of the radial lines INSIDE of the smaller circle. I am going to give you a hint how to do this fast! Instead of taking the Erase command and clicking on something you want to erase, pick the Erase command, move your cursor into the middle of the circle, hold down the left mouse button and move the cursor around the drawing. (Remember, you only want to erase the lines that are inside of the small circle) If you hold the mouse button and move the cursor around, all of the lines should turn blue. As soon as you release the left mouse button, they will all disappear! You may have to practice this a few times. Remember, if you make a mistake, you can always hit the Undo tool and it will go back to where it was right before you made the mistake. The first picture below shows the lines all lit up blue (this means that all of the blue lines will be erased). The second picture shows all of the lines erased:

8 Now you need to erase some of the outside circle segments; but NOT ALL OF THEM!! Take your time and erase every other LINE SEGMENT on the outside circle. I ll erase a few of them so you can see what it should look like. Look at the picture below:

9 Notice that I erased two of the short line segments, but left the one in between! Erase one, skip one, and then keep repeating. Keep erasing EVERY OTHER line segment all the way around the circle. It should look like the picture below:

10 Now, you are going to go and erase every other of the little short lines that are on the inner circle. I ll show you which ones to erase in the picture below: Erase these little lines (the white arrows) all the way around the circle. Don t erase the ones with the red arrow, or the circle will go away! Remember, if you make a mistake, just use the undo tool to back up. It should look like the picture below:

11 The next step is to use the Push/Pull tool and pull up the shape that you have drawn. Now the final step is to use the rotate tool. But we re not going to use the rotate tool on the entire drawing, just part of it. The way to do that is to use the Select tool to click and drag (highlight) just the top of the object, not the whole thing. Like the picture below:

12 When you have selected (highlighted) it correctly, only the top will be lit up a blue color: Next, you will hit the Q button on the keyboard. A compass will show up. Move it until it is over the center of the object we just made. The compass should be blue in color.

13 Now, click the left mouse button, move the cursor to the right side and click the mouse button again. Move the cursor around a little bit, then click one more time. The top of the object should rotate around. Practice a little bit if you need to. It should look like the picture below: Finally, you are going to draw a circle in the middle of the top of the thing you just drew, then push the circle down a little bit. I won t tell you the steps, you have to figure this last part out on your own: You are now done! You made a gear!