WEBVTT 00:00:00.200 --> 00:00:02.200 As you work to develop CAD fluency, 00:00:02.279 --> 00:00:05.550 which means to be able to do your CAD work quickly and accurately, 00:00:05.800 --> 00:00:08.949 it helps to have a good CAD process. 00:00:09.210 --> 00:00:13.189 Now, a good CAD process always starts with understanding 00:00:13.470 --> 00:00:15.229 the purpose for the CAD work. 00:00:15.399 --> 00:00:15.920 In other words, 00:00:16.350 --> 00:00:18.309 understanding the job that needs to be done. 00:00:18.600 --> 00:00:20.350 Now in the product development process, 00:00:20.639 --> 00:00:24.200 we have a variety of ways that we understand the job that needs to be done. 00:00:24.319 --> 00:00:24.750 For example, 00:00:24.799 --> 00:00:25.200 we might 00:00:25.649 --> 00:00:25.850 read 00:00:25.889 --> 00:00:30.319 a design brief or have a discussion with a client or anything like that. 00:00:30.690 --> 00:00:36.529 But in the process of learning CAD and being given exercises and 00:00:36.849 --> 00:00:39.319 activities the way we're doing in this course, 00:00:39.729 --> 00:00:43.500 one of the important ways for you to understand the job that needs to be done 00:00:43.889 --> 00:00:44.439 is 00:00:44.689 --> 00:00:46.279 to be able to read 00:00:46.569 --> 00:00:49.529 and interpret correctly an engineering drawing. 00:00:50.150 --> 00:00:50.950 Usually, 00:00:51.270 --> 00:00:54.619 in this course, for the purpose of reproducing the geometry 00:00:55.029 --> 00:00:55.540 found 00:00:55.790 --> 00:00:57.459 in those engineering drawings. 00:00:57.590 --> 00:00:58.659 So, in this video, 00:00:58.909 --> 00:01:02.779 I'll take the time to describe to you part drawings 00:01:03.060 --> 00:01:04.430 and assembly drawings. 00:01:04.529 --> 00:01:05.800 And I will simply 00:01:06.349 --> 00:01:06.849 attempt 00:01:07.110 --> 00:01:10.339 to demystify what otherwise may appear 00:01:10.669 --> 00:01:13.019 like a complicated set of documents. 00:01:13.110 --> 00:01:16.110 But as soon as you sort of break them down and see what's in them, 00:01:16.470 --> 00:01:21.540 you'll be able to begin the process of reading and interpreting them correctly. 00:01:21.750 --> 00:01:24.349 So, I'm gonna jump right now into a set of graphics. 00:01:24.430 --> 00:01:27.269 We're gonna take a look at these graphics now, and we can see 00:01:28.410 --> 00:01:29.309 there is a product here. 00:01:29.370 --> 00:01:30.760 It is a turbocharger. 00:01:31.089 --> 00:01:33.750 This particular turbocharger for the discussion 00:01:34.010 --> 00:01:38.059 that we're gonna have right now has two pages 00:01:38.290 --> 00:01:39.000 of a drawing. 00:01:39.169 --> 00:01:40.959 So, the drawing is shown right here. 00:01:41.169 --> 00:01:42.800 We're gonna look at sheet 1 00:01:43.089 --> 00:01:44.319 of this drawing set, 00:01:44.569 --> 00:01:45.940 and we're just gonna start 00:01:46.330 --> 00:01:48.440 breaking down its pieces, 00:01:48.809 --> 00:01:51.209 and then we'll look at sheet 2, and then we're gonna 00:01:51.209 --> 00:01:54.610 spend a little bit of time looking at an assembly drawing. 00:01:55.339 --> 00:01:55.349 OK. 00:01:56.290 --> 00:01:57.319 For sheet 1, 00:01:57.769 --> 00:02:01.809 we need to understand that the overall graphic that's 00:02:01.809 --> 00:02:04.120 around the edge is called the sheet format. 00:02:04.330 --> 00:02:04.680 In fact, 00:02:04.730 --> 00:02:05.180 we can 00:02:05.370 --> 00:02:08.440 just sort of take out all the geometry and specific 00:02:08.809 --> 00:02:12.809 geometric information and what's left is called the sheet format. 00:02:13.470 --> 00:02:14.059 All right. 00:02:14.190 --> 00:02:16.419 The sheet format has zone markers. 00:02:16.630 --> 00:02:20.259 These zone markers are used for to facilitate communication 00:02:20.550 --> 00:02:24.220 on design teams or across a large geographic distances. 00:02:24.229 --> 00:02:24.740 We can say, 00:02:24.750 --> 00:02:25.039 hey, 00:02:25.309 --> 00:02:29.070 something's going on in C2, area C2, of the drawing. 00:02:29.110 --> 00:02:30.940 Let's take a look and see what that is. 00:02:32.470 --> 00:02:34.259 Also, in 00:02:34.619 --> 00:02:35.309 the 00:02:35.630 --> 00:02:38.539 drawing we have the thing that is called the revision block. 00:02:38.669 --> 00:02:41.229 The revision block describes the latest change at 00:02:41.229 --> 00:02:42.869 least that has been made to the drawing. 00:02:42.949 --> 00:02:43.740 In this case, 00:02:44.070 --> 00:02:45.220 it's a revision A, 00:02:45.270 --> 00:02:47.539 meaning it's just the initial release. 00:02:47.990 --> 00:02:50.740 The revision block only appears on sheet 1. 00:02:51.509 --> 00:02:55.539 We also have the thing on the drawing that's called the title block. 00:02:55.669 --> 00:02:56.630 The title block 00:02:56.880 --> 00:02:59.389 has a lot of very important information. 00:02:59.630 --> 00:03:02.020 And within the title block, we find things that 00:03:02.020 --> 00:03:05.250 are critical for being able to reproduce the geometry 00:03:05.619 --> 00:03:06.479 that's in 00:03:06.940 --> 00:03:10.149 the drawing. And so, we're gonna take a deeper look now at the title block, 00:03:10.419 --> 00:03:13.380 and we're gonna look at three separate parts of the title block. 00:03:13.500 --> 00:03:17.649 First, we're gonna take a look at this part here, which, of course, has like the title, 00:03:17.940 --> 00:03:19.610 also has a thing called 00:03:19.850 --> 00:03:23.979 the size, and, by the way, we are looking at B size drawings. 00:03:24.020 --> 00:03:26.490 These are 11 by 17 00:03:27.309 --> 00:03:28.029 inches. 00:03:28.149 --> 00:03:29.899 That's how big those drawings are. 00:03:30.149 --> 00:03:32.759 Now, a couple of key things to pay attention to here. 00:03:33.080 --> 00:03:35.830 Item number 1 is you should always have a sense 00:03:35.830 --> 00:03:38.699 for what revision of the drawing you're looking at. 00:03:38.990 --> 00:03:40.990 This is important because occasionally you'll 00:03:40.990 --> 00:03:43.179 be working with a colleague or another 00:03:43.589 --> 00:03:44.990 entity, 00:03:45.130 --> 00:03:47.259 maybe a supplier or something like this, 00:03:47.470 --> 00:03:50.309 and you want to make sure that you're on the same page. And the 00:03:50.309 --> 00:03:53.300 way we do that is you make sure you're looking at the same revision 00:03:53.589 --> 00:03:54.350 of the drawing. 00:03:54.899 --> 00:03:56.039 Speaking of pages, 00:03:56.380 --> 00:03:58.130 which is not what I meant just a minute ago, 00:03:58.419 --> 00:03:59.369 there 00:03:59.539 --> 00:04:00.130 are 00:04:00.380 --> 00:04:02.330 multiple sheets in this drawing set, 00:04:02.380 --> 00:04:04.740 and there's always a list of how many sheets there are. 00:04:04.820 --> 00:04:07.660 That's important to know because if there's additional information on 00:04:07.660 --> 00:04:10.220 sheet 2 or 3 or 4 or 5 or 6, 00:04:10.259 --> 00:04:11.889 we want to go and get them. 00:04:12.539 --> 00:04:13.770 Also, we have 00:04:14.389 --> 00:04:16.209 information that is 00:04:16.399 --> 00:04:18.329 related to the overall 00:04:19.390 --> 00:04:24.170 mass properties of the object represented in the drawing. In this case, the weight 00:04:24.540 --> 00:04:29.010 is shown, and then also here to pay attention to is the scale. 00:04:29.260 --> 00:04:33.929 The scale is important to understand in the sense that if the scale was 1 to 1, 00:04:34.260 --> 00:04:38.450 then the object in the drawing would be printed 00:04:38.700 --> 00:04:41.820 on the drawing at the same size as the actual object. 00:04:42.279 --> 00:04:43.790 When the scale is 1 to 5, 00:04:43.920 --> 00:04:44.429 in this case, 00:04:44.480 --> 00:04:48.119 every 1 inch that's printed on the drawing represents 5 inches 00:04:48.519 --> 00:04:48.910 in 00:04:49.119 --> 00:04:49.989 reality. 00:04:50.279 --> 00:04:50.429 All right. 00:04:50.440 --> 00:04:54.399 The next part of the title block that we're gonna take a look at captures authorship. 00:04:54.679 --> 00:04:58.429 And also, thedrawing has been checked, and frankly, you should 00:04:58.920 --> 00:05:01.239 always have your drawings checked. And you should not 00:05:01.239 --> 00:05:03.359 trust drawings that have not yet been checked. 00:05:04.000 --> 00:05:07.029 Also, in this part of the drawing, we find the units 00:05:07.359 --> 00:05:07.950 for 00:05:08.209 --> 00:05:09.799 how the drawing was created. 00:05:09.839 --> 00:05:12.880 In this case, this drawing is in the units of millimeters. 00:05:13.480 --> 00:05:15.149 We also find the important 00:05:15.649 --> 00:05:21.200 area that is describing the material of the object represented in the drawing. 00:05:21.209 --> 00:05:21.869 In this case, 00:05:22.010 --> 00:05:25.399 the turbocharger in the drawing is of titanium grade 5. 00:05:25.970 --> 00:05:28.329 Also, in the drawing, we can find 00:05:28.540 --> 00:05:30.579 finish if there is one specified and if there's 00:05:30.579 --> 00:05:32.450 not one specified, it will simply say that. 00:05:32.459 --> 00:05:32.940 And then, 00:05:33.220 --> 00:05:36.049 also, here there's a section for comments. And in this course, 00:05:36.339 --> 00:05:39.109 this is where we actually put our color specifications. 00:05:39.649 --> 00:05:39.709 This 00:05:39.739 --> 00:05:43.019 is not a color specification for the turbocharger. 00:05:43.059 --> 00:05:44.769 This would have meant the turbocharger was 00:05:45.220 --> 00:05:46.459 perfectly red. 00:05:47.010 --> 00:05:47.380 But 00:05:47.450 --> 00:05:50.010 I have just put that in there as a quick sample just 00:05:50.010 --> 00:05:53.920 to show you that those will often show up in our comments. 00:05:54.089 --> 00:05:56.769 We also then have this other part of the title block, 00:05:57.089 --> 00:05:59.420 which is the sheet tolerances. 00:05:59.579 --> 00:06:01.450 Now, what's going on with sheet tolerances? 00:06:01.529 --> 00:06:01.820 First of all, 00:06:01.850 --> 00:06:03.839 we have to know that this part represents 00:06:04.209 --> 00:06:07.809 important information relative to the dimensions in the drawing. 00:06:08.850 --> 00:06:10.929 So, we're going to go look at one of the dimensions right now. 00:06:11.000 --> 00:06:11.549 From the 00:06:11.799 --> 00:06:14.829 top edge of this object to the center of this hole 00:06:15.119 --> 00:06:19.079 is supposed to be 23.00 millimeters. 00:06:19.679 --> 00:06:24.790 Now, we can understand from this part of the drawing and from the sheet tolerances 00:06:25.109 --> 00:06:26.429 that what this means 00:06:26.799 --> 00:06:28.010 is that because our 00:06:28.625 --> 00:06:29.494 has two 00:06:32.144 --> 00:06:34.494 bits of information beyond the decimal point, 00:06:34.785 --> 00:06:36.575 then we will be referring to 00:06:36.904 --> 00:06:39.135 this portion in the general 00:06:39.785 --> 00:06:40.464 tolerances, 00:06:40.505 --> 00:06:41.695 the sheet tolerances, 00:06:41.984 --> 00:06:44.355 which mean that the 23 00:06:44.665 --> 00:06:47.475 is plus or minus 0.15 millimeters. 00:06:48.184 --> 00:06:48.575 Now, 00:06:48.864 --> 00:06:51.945 if our drawing would have instead just had one 00:06:52.329 --> 00:06:55.190 bit of information beyond the decimal spot, 00:06:55.359 --> 00:06:59.170 we would have been looking at plus or minus 0.25 millimeters. 00:06:59.559 --> 00:07:03.070 Now, this is important because all of those tolerances are essential, 00:07:03.359 --> 00:07:04.579 but we don't want to put them, 00:07:04.720 --> 00:07:07.350 every single one of them on the drawing itself 00:07:07.880 --> 00:07:09.029 because it will 00:07:09.609 --> 00:07:10.649 clutter up the drawings. 00:07:10.679 --> 00:07:12.200 So, they go into the sheet 00:07:12.750 --> 00:07:15.320 definition, so into the sheet tolerances. 00:07:15.630 --> 00:07:17.309 That's what that means. 00:07:17.429 --> 00:07:17.859 OK. 00:07:18.029 --> 00:07:21.190 Well, those were the main things that we wanted to look at in the 00:07:21.190 --> 00:07:24.959 title block. We have finished our sort of deep dive on the title block. 00:07:25.230 --> 00:07:28.670 And then, I'll just go through a few other things here and say that 00:07:29.029 --> 00:07:31.019 drawings always have 00:07:31.309 --> 00:07:33.390 a set of general drawing notes. 00:07:33.429 --> 00:07:36.549 These drawing notes apply to the entire drawing 00:07:37.010 --> 00:07:37.410 set, 00:07:37.779 --> 00:07:39.299 sometimes just the entire page, 00:07:39.350 --> 00:07:42.279 but sometimes it can apply to all the sheets. 00:07:42.450 --> 00:07:46.440 But then we also have specific notes that can apply to just a specific 00:07:46.809 --> 00:07:51.100 part located or a specific portion of a part located on the drawing, 00:07:51.130 --> 00:07:52.760 and there's always a leader line 00:07:53.010 --> 00:07:55.730 that is connected to where that note matters. 00:07:56.529 --> 00:07:56.549 All right. 00:07:57.519 --> 00:07:59.739 Now, we have to look at the geometry 00:08:00.040 --> 00:08:05.190 of the drawing. Here, we have what's called the orthographic projections, 00:08:05.399 --> 00:08:08.119 the orthographic projection views we could call them. 00:08:08.200 --> 00:08:08.670 OK. 00:08:08.880 --> 00:08:09.390 And then, 00:08:09.519 --> 00:08:10.869 we also have 00:08:11.279 --> 00:08:15.839 within those orthographic projection views, a special kind of line that we don't 00:08:15.839 --> 00:08:19.480 see anywhere else and that is a dashed line and that dashed line 00:08:19.614 --> 00:08:22.084 is called a hidden line. And a hidden line is 00:08:22.084 --> 00:08:25.394 like an X-ray view we basically can see into the object 00:08:25.725 --> 00:08:27.725 and what all the dashed line 00:08:27.725 --> 00:08:30.994 are representing internal geometry 00:08:31.244 --> 00:08:33.275 that we can't see from outside but we 00:08:33.604 --> 00:08:36.354 can see through in an X-ray sort of form. 00:08:36.683 --> 00:08:38.715 Now, there is another image 00:08:39.005 --> 00:08:42.525 on here, another view, it's called the isometric view it's the one at the top 00:08:43.169 --> 00:08:46.440 right of the drawing, and the top right drawing 00:08:46.710 --> 00:08:50.320 view the isometric view never has hidden lines. 00:08:50.539 --> 00:08:50.780 This 00:08:50.789 --> 00:08:55.380 is a standard for drawing so we can always see the isometric view 00:08:55.590 --> 00:08:59.229 and we can have a sense for what the object is that's to help us with that, 00:08:59.309 --> 00:09:01.830 but it's not gonna show us hidden lines. 00:09:01.950 --> 00:09:02.989 Now, it's worth spending 00:09:03.565 --> 00:09:03.924 just 00:09:03.934 --> 00:09:06.005 a little bit of time trying 00:09:06.005 --> 00:09:09.405 to understand what is this orthographic projection. 00:09:09.645 --> 00:09:12.994 If you understand the thing that I'm going to describe in the next moment, 00:09:13.244 --> 00:09:16.395 then orthographic projections will become meaningful to you, 00:09:16.604 --> 00:09:17.364 will become useful, 00:09:17.375 --> 00:09:19.734 and you'll be able to understand engineering drawings 00:09:20.085 --> 00:09:20.474 of 00:09:20.565 --> 00:09:23.354 this form indefinitely into the future. 00:09:23.575 --> 00:09:26.794 So, I'm gonna show you the same orthographic projections 00:09:27.205 --> 00:09:27.965 shown 00:09:28.700 --> 00:09:31.080 in just a little bit larger here, 00:09:31.369 --> 00:09:34.799 and what we want to do is take a look at the front view for a second. 00:09:35.010 --> 00:09:36.700 When we're looking at the front view, 00:09:37.090 --> 00:09:37.440 what 00:09:37.489 --> 00:09:39.159 we are really looking at 00:09:39.500 --> 00:09:40.359 is 00:09:40.369 --> 00:09:41.000 a 00:09:41.369 --> 00:09:42.880 projection 00:09:43.409 --> 00:09:46.919 of the object directly onto its front face. 00:09:47.289 --> 00:09:47.719 Now, 00:09:48.169 --> 00:09:52.640 if you can see the red box that's on the right-hand side here, 00:09:53.130 --> 00:09:55.929 the front view is exactly the front view direction. 00:09:56.780 --> 00:09:56.969 Now, 00:09:57.000 --> 00:09:58.030 if I were to 00:09:58.520 --> 00:10:00.320 take a line 00:10:00.960 --> 00:10:04.770 and draw it on the paper between the top view and the front view 00:10:05.119 --> 00:10:08.510 and then fold it right there at 90 degrees, 00:10:08.719 --> 00:10:10.390 I would create the edge of a cube. 00:10:11.020 --> 00:10:13.210 And the edge of that cube would be such that when I 00:10:13.210 --> 00:10:16.359 look down from the top of the cube, I see the top view, 00:10:16.650 --> 00:10:19.260 and when I look at the front of the cube, I see the front view. 00:10:19.530 --> 00:10:20.250 Now, likewise, 00:10:20.369 --> 00:10:23.090 if I were to fold between the front view and 00:10:23.090 --> 00:10:25.789 the right view and leave the paper at 90 degrees, 00:10:25.809 --> 00:10:27.200 I'd form another 00:10:27.570 --> 00:10:28.849 edge of a cube. 00:10:29.590 --> 00:10:32.099 And when I look at the right side of that cube, I would 00:10:32.099 --> 00:10:34.299 see the right view, and when I look at the front view, 00:10:34.419 --> 00:10:36.380 I would see the front view, and if I look at the top view, 00:10:36.460 --> 00:10:37.549 I'd see the top view. 00:10:37.739 --> 00:10:41.679 And this is how an orthographic projection works. 00:10:41.820 --> 00:10:42.969 It's simple 00:10:43.739 --> 00:10:45.280 when someone has described it to you, 00:10:45.349 --> 00:10:46.570 but is otherwise, 00:10:48.109 --> 00:10:48.789 for some people, 00:10:48.830 --> 00:10:51.270 not super obvious. So, hopefully, you will walk 00:10:51.270 --> 00:10:53.330 away with a little bit of information there 00:10:53.590 --> 00:10:54.940 on how to interpret 00:10:55.229 --> 00:10:55.700 these 00:10:55.989 --> 00:10:57.820 orthographic projections. 00:10:58.109 --> 00:11:01.859 So, now, you should be able to look at an engineering drawing like this 00:11:02.150 --> 00:11:04.789 and not get super overwhelmed by it because 00:11:04.789 --> 00:11:06.979 you know that all the information around the edge 00:11:07.429 --> 00:11:08.809 is the sheet format. 00:11:09.030 --> 00:11:11.390 You know that down in the bottom right corner, we 00:11:11.390 --> 00:11:14.299 have our title block with a bunch of essential information. 00:11:14.510 --> 00:11:16.429 We have our revision block at the top right. 00:11:16.880 --> 00:11:19.080 Then, we have two kinds of views here. 00:11:19.159 --> 00:11:22.400 We have the orthographic projections, which have the front, 00:11:22.599 --> 00:11:22.789 right, 00:11:22.799 --> 00:11:25.669 and top view, and then we have the isometric view, 00:11:26.000 --> 00:11:30.869 which is shown without hidden lines in the top right portion of the drawing 00:11:31.080 --> 00:11:32.289 and helps us get 00:11:32.440 --> 00:11:35.250 even a better sense for what the object is all about. 00:11:36.289 --> 00:11:36.869 OK. 00:11:37.169 --> 00:11:39.159 That was what sheet 1 looked like. 00:11:39.530 --> 00:11:40.000 Now, 00:11:40.270 --> 00:11:41.130 in sheet 1, 00:11:41.229 --> 00:11:43.119 we saw those orthographic projections; 00:11:43.210 --> 00:11:45.080 we saw the isometric view. 00:11:46.159 --> 00:11:47.880 And in sheet 2, 00:11:48.039 --> 00:11:50.039 we see what is called auxiliary views. 00:11:50.119 --> 00:11:50.239 Now, 00:11:50.250 --> 00:11:52.270 auxiliary views are not limited to 00:11:52.599 --> 00:11:53.640 being on page 2, 00:11:53.719 --> 00:11:55.119 they could be on page 1. 00:11:55.830 --> 00:11:57.080 But in this case, 00:11:57.320 --> 00:11:58.669 in this particular drawing, 00:11:58.960 --> 00:12:01.789 our auxiliary views happen to be on sheet 2. 00:12:02.000 --> 00:12:04.510 They could have been on sheet 3, 4, 5, 6, 00:12:04.679 --> 00:12:05.309 or 1. 00:12:05.559 --> 00:12:06.000 OK. 00:12:06.780 --> 00:12:08.700 Now in order to understand the auxiliary views, 00:12:08.780 --> 00:12:09.520 we need to 00:12:09.859 --> 00:12:11.210 zoom in just a bit 00:12:11.500 --> 00:12:13.659 on this portion of sheet 1 00:12:14.059 --> 00:12:15.700 and see what's going on here. 00:12:16.020 --> 00:12:18.210 Within this set portion, 00:12:18.380 --> 00:12:20.770 when we're looking at the front view from sheet 1, 00:12:21.020 --> 00:12:24.289 we see this dashed line with the two arrows on it. 00:12:24.609 --> 00:12:26.530 This is called a section marker, 00:12:26.700 --> 00:12:30.530 and what a section marker means is that we are going to slice the part 00:12:30.830 --> 00:12:32.739 right where the dashed line is, and then we're going 00:12:32.739 --> 00:12:36.460 to look in the directions of the arrows labeled AA. 00:12:36.750 --> 00:12:38.340 And what are we gonna see if we do that? 00:12:38.380 --> 00:12:39.250 We're gonna see 00:12:39.460 --> 00:12:40.809 this box that's now 00:12:41.099 --> 00:12:42.739 highlighted on sheet 2. 00:12:43.059 --> 00:12:45.010 How do we know that that's the box we're gonna see? 00:12:45.140 --> 00:12:45.260 Well, 00:12:45.390 --> 00:12:47.770 primarily, we know it's the box we're gonna see because 00:12:47.969 --> 00:12:48.809 it's labeled. 00:12:49.020 --> 00:12:53.179 It's called section AA, and that's exactly what we were looking at 00:12:53.179 --> 00:12:57.820 in sheet 1 was a marker showing what section AA would be. 00:12:58.140 --> 00:12:59.239 And now on sheet 2, 00:12:59.280 --> 00:12:59.880 we're looking at that. 00:12:59.960 --> 00:13:00.609 So, we're going to 00:13:00.840 --> 00:13:03.510 go take a look even deeper now at sheet 2. 00:13:03.760 --> 00:13:05.640 Now that we know that we're looking at 2 00:13:06.030 --> 00:13:07.159 section views, 00:13:07.280 --> 00:13:09.280 section views are auxiliary views. 00:13:10.080 --> 00:13:10.400 Alright, 00:13:10.520 --> 00:13:12.669 now a few things to point out on this sheet. 00:13:13.000 --> 00:13:13.669 We have 00:13:14.229 --> 00:13:17.229 the name of the auxiliary view with its scale, 00:13:17.400 --> 00:13:19.869 if it has been scaled, and this one has been scaled. 00:13:20.710 --> 00:13:21.869 We also see that 00:13:22.109 --> 00:13:25.049 there's a new kind of line that's appearing on the drawing, 00:13:25.070 --> 00:13:26.460 and this is the crosshatch. 00:13:26.669 --> 00:13:27.909 Whenever there's a crosshatch, 00:13:27.989 --> 00:13:30.419 this means that we have sliced through material 00:13:30.630 --> 00:13:33.979 and we're actually looking at material and not void space. 00:13:34.229 --> 00:13:34.859 So, for example, 00:13:34.909 --> 00:13:37.739 if we look at the holes that are on the same view, 00:13:38.030 --> 00:13:39.950 those holes are not crosshatched, that means 00:13:39.950 --> 00:13:42.299 they're void space. It means there's nothing there, 00:13:42.590 --> 00:13:46.309 but the crosshatch means there is something there and that's material. 00:13:46.830 --> 00:13:47.070 All right. 00:13:47.190 --> 00:13:48.820 What is the next piece we're gonna look at? 00:13:48.950 --> 00:13:53.059 We're gonna notice here that there are center lines and center marks. 00:13:53.429 --> 00:13:54.859 These pieces of 00:13:55.929 --> 00:13:57.809 sort of invisible geometry, 00:13:57.869 --> 00:13:59.059 maybe we can call them, 00:13:59.309 --> 00:14:01.750 are important for dimensioning too 00:14:02.330 --> 00:14:05.349 or understanding symmetries in some cases. 00:14:05.809 --> 00:14:06.049 All right. 00:14:06.169 --> 00:14:09.679 We also have in this sheet 2 dimensions, 00:14:10.000 --> 00:14:10.969 such as this dimension, 00:14:11.010 --> 00:14:16.210 which means that the overall length of this object is 268 millimeters. 00:14:16.729 --> 00:14:18.770 We also see some other dimensions, 00:14:18.929 --> 00:14:21.520 some that appear a little bit more complicated. 00:14:21.770 --> 00:14:23.590 And what this dimension means, 00:14:24.010 --> 00:14:25.239 the dimension that says 00:14:25.570 --> 00:14:28.960 4X R20.00 00:14:29.369 --> 00:14:29.859 means 00:14:30.130 --> 00:14:33.890 that there are four arcs on this part that have a radius 00:14:34.369 --> 00:14:35.419 of 20 millimeters. 00:14:36.010 --> 00:14:37.520 And then, likewise, 00:14:37.849 --> 00:14:39.700 there is a dimension here that says 00:14:40.049 --> 00:14:44.080 there are four circles on this part that have a diameter 00:14:44.369 --> 00:14:46.630 of 20 millimeters. So, when there's an R, 00:14:47.010 --> 00:14:49.039 this is a dimension that goes on an arc 00:14:49.409 --> 00:14:55.090 or an incomplete circle when there is the diameter symbol or the letters DIA. 00:14:55.640 --> 00:14:59.989 This means that this is a diameter and we do that for full circles. 00:15:00.200 --> 00:15:03.549 The 4X that precedes it in this case simply means that 00:15:03.799 --> 00:15:04.750 there are four 00:15:04.919 --> 00:15:07.669 identical geometries on this part 00:15:07.919 --> 00:15:09.190 that have that same 00:15:09.440 --> 00:15:10.049 dimension. 00:15:11.099 --> 00:15:14.940 Now, of course, on this drawing, there are many dimensions. That is the purpose 00:15:15.190 --> 00:15:19.580 of the drawing is actually to convey geometric information. 00:15:19.989 --> 00:15:24.080 And don't forget the rectangular red box there in the title block 00:15:24.270 --> 00:15:26.520 the drawing is also designed to convey 00:15:27.109 --> 00:15:28.190 material information. 00:15:28.679 --> 00:15:28.919 All right. 00:15:29.080 --> 00:15:30.880 So, we have just taken a look at 00:15:31.289 --> 00:15:32.080 part drawings. 00:15:32.119 --> 00:15:32.630 In this case, 00:15:32.679 --> 00:15:35.409 a multi-sheet part drawing for this turbocharger. 00:15:35.719 --> 00:15:36.590 And hopefully, 00:15:36.840 --> 00:15:37.320 we have, 00:15:37.440 --> 00:15:38.400 as I mentioned before, 00:15:38.599 --> 00:15:40.229 demystified it a little bit 00:15:40.479 --> 00:15:41.450 and shown 00:15:41.840 --> 00:15:43.599 that it is full of 00:15:44.609 --> 00:15:46.640 orthographic projection views, 00:15:47.000 --> 00:15:48.450 isometric views, 00:15:48.679 --> 00:15:50.229 and some auxiliary views, 00:15:50.520 --> 00:15:54.510 and then those allow dimensions to be put onto 00:15:54.869 --> 00:15:58.239 the object that help us understand more and more about it. 00:15:58.700 --> 00:15:59.380 OK. 00:15:59.549 --> 00:16:03.020 It is now time for us to stop thinking about part drawings, 00:16:03.030 --> 00:16:04.190 and we're going to talk about 00:16:04.469 --> 00:16:08.390 assembly drawings. And in this case, I'm showing you a five 00:16:08.390 --> 00:16:12.789 sheet assembly drawing for the NES game controller by Nintendo. 00:16:13.190 --> 00:16:16.020 Now, it's five sheets because we need to know 00:16:16.469 --> 00:16:18.619 this thing in the top left corner 00:16:18.909 --> 00:16:20.820 is just an isometric 00:16:21.409 --> 00:16:22.520 screenshot 00:16:22.869 --> 00:16:25.020 just to let you know the object that we're working on. 00:16:25.070 --> 00:16:27.590 It's not part of the actual drawing set. 00:16:28.109 --> 00:16:28.349 All right, 00:16:28.510 --> 00:16:29.830 so within this drawing set, 00:16:29.919 --> 00:16:30.469 however, 00:16:31.690 --> 00:16:36.090 there are five sheets. And we're going to take a look at just three of those sheets— 00:16:36.239 --> 00:16:36.760 sheet 1, 00:16:37.000 --> 00:16:37.559 sheet 2, 00:16:37.599 --> 00:16:38.469 and sheet 3. 00:16:38.640 --> 00:16:39.830 The other sheets are valuable, 00:16:39.960 --> 00:16:42.799 but they're not going to teach us anything new about how to interpret 00:16:43.650 --> 00:16:44.739 an assembly drawing, 00:16:44.789 --> 00:16:46.460 which is what we're gonna do right now. 00:16:46.799 --> 00:16:47.260 All right, 00:16:47.549 --> 00:16:49.869 take a look at this first sheet 00:16:50.150 --> 00:16:50.820 of the 00:16:51.030 --> 00:16:54.940 Nintendo NES game controller, and let's notice first of all 00:16:55.270 --> 00:16:57.710 the things that are similar from the part drawing, 00:16:58.570 --> 00:16:59.969 part drawings that we looked at. 00:17:00.320 --> 00:17:03.450 Sheet formats the same exact concept; zone marker, 00:17:03.609 --> 00:17:07.930 same concept; revision block, the same; title block, same concept; 00:17:07.930 --> 00:17:12.640 general notes, same concept. We have orthographic projection views here. 00:17:13.089 --> 00:17:16.848 We also have isometric views, and we also have dimensions. 00:17:17.010 --> 00:17:18.290 So, what's new then? 00:17:18.479 --> 00:17:18.709 Well, 00:17:18.930 --> 00:17:20.358 there are some new things here. 00:17:20.810 --> 00:17:22.680 We have assembly dimensions. 00:17:22.890 --> 00:17:25.810 These are dimensions that don't exist on any part drawing. 00:17:26.208 --> 00:17:30.529 This is one of the main purposes of assembly drawings is to help convey 00:17:30.889 --> 00:17:32.519 dimensions that are essential, 00:17:32.848 --> 00:17:34.649 but don't exist on part drawings. 00:17:34.729 --> 00:17:35.438 For example, 00:17:35.808 --> 00:17:36.598 this is 00:17:37.078 --> 00:17:38.918 measuring from one edge 00:17:39.660 --> 00:17:42.579 of a part to another edge of another part. 00:17:43.369 --> 00:17:45.369 That 17.20. 00:17:45.920 --> 00:17:46.079 All right. 00:17:46.119 --> 00:17:49.890 We also can notice here in the title block 00:17:50.199 --> 00:17:52.150 that material and finish 00:17:52.520 --> 00:17:54.630 don't make a lot of sense 00:17:54.920 --> 00:17:57.359 in an assembly drawing because the assembly is 00:17:57.359 --> 00:18:00.599 made up of various parts that all have potentially 00:18:00.880 --> 00:18:03.030 different materials and different finishes. 00:18:03.359 --> 00:18:05.510 And therefore, it is traditional 00:18:05.839 --> 00:18:06.949 and expected 00:18:07.160 --> 00:18:09.000 that those bits of information 00:18:09.380 --> 00:18:11.099 don't exist on the assembly drawing, 00:18:11.140 --> 00:18:13.500 but that the reader of the assembly drawing is 00:18:14.750 --> 00:18:16.680 encouraged or directed 00:18:16.949 --> 00:18:19.089 to the actual art drawings. 00:18:19.390 --> 00:18:19.670 All right, 00:18:19.790 --> 00:18:20.310 let's 00:18:20.709 --> 00:18:21.410 take 00:18:22.209 --> 00:18:23.449 a look at, 00:18:23.729 --> 00:18:23.800 oh, 00:18:23.930 --> 00:18:26.439 that's the part that I just talked about right now. 00:18:27.439 --> 00:18:28.060 OK. 00:18:28.500 --> 00:18:30.209 Now on to sheet 2. 00:18:30.459 --> 00:18:30.739 All right. 00:18:30.939 --> 00:18:31.969 For sheet 2, 00:18:32.020 --> 00:18:36.020 it's essential to realize that there is a new kind of auxiliary 00:18:36.020 --> 00:18:39.010 view that we're looking at now and it's called an exploded view. 00:18:39.420 --> 00:18:41.180 And the beauty of the exploded view 00:18:42.410 --> 00:18:45.319 is that it's broken up the part into all of its 00:18:45.319 --> 00:18:47.550 pieces so we can take a deeper look at them. 00:18:47.920 --> 00:18:48.170 Now, 00:18:48.199 --> 00:18:50.760 each of the parts has a callout balloon on it. 00:18:51.030 --> 00:18:55.739 And the callout balloon has a corresponding line in this table which 00:18:55.739 --> 00:18:59.489 is called the bill of materials or sometimes called the part list, 00:18:59.500 --> 00:19:01.500 but we will call it the bill of materials. 00:19:01.619 --> 00:19:03.439 Now, all of the objects 00:19:03.819 --> 00:19:04.770 in 00:19:05.099 --> 00:19:06.689 this particular assembly 00:19:06.939 --> 00:19:11.369 have a callout balloon and have a location in the bill of materials. 00:19:11.500 --> 00:19:15.660 Also, in the assembly drawing, we can notice the thing that's called the explode line. 00:19:15.959 --> 00:19:19.469 The explode line helps to understand that, for example, 00:19:19.469 --> 00:19:23.510 the bottom left the screw goes through that bottom cover 00:19:23.959 --> 00:19:25.229 through the circuit board 00:19:25.640 --> 00:19:26.109 through 00:19:26.359 --> 00:19:29.579 the membrane and up into the top cover, 00:19:29.839 --> 00:19:31.550 and it is an indication 00:19:31.800 --> 00:19:32.949 of how these 00:19:33.280 --> 00:19:35.390 parts line up with each other. 00:19:35.760 --> 00:19:35.959 OK. 00:19:36.010 --> 00:19:38.199 We're now going to take a look at step, excuse me, 00:19:38.349 --> 00:19:39.160 sheet 3. 00:19:39.459 --> 00:19:40.750 And in sheet 3, 00:19:40.959 --> 00:19:41.869 we're going to see 00:19:42.199 --> 00:19:46.030 that a number of things are the same as they were in part drawings. 00:19:46.469 --> 00:19:46.869 For example, 00:19:46.959 --> 00:19:48.000 the section markers, 00:19:48.079 --> 00:19:49.040 the section views, 00:19:49.160 --> 00:19:50.079 the general nodes, 00:19:50.199 --> 00:19:51.359 the specific notes. 00:19:52.140 --> 00:19:53.609 But we now have a new thing 00:19:53.839 --> 00:19:57.239 that could have existed in a part drawing but it 00:19:57.239 --> 00:19:59.910 didn't exist in our part drawing for the turbocharger. 00:19:59.959 --> 00:20:01.109 It exists in this one, 00:20:01.280 --> 00:20:03.150 so I thought I'd take a second to talk about it 00:20:03.319 --> 00:20:05.109 and that is called the detail view. 00:20:05.439 --> 00:20:07.989 And a detail view is another auxiliary view 00:20:08.280 --> 00:20:11.280 and what it is is it's a zoomed in portion 00:20:11.839 --> 00:20:12.380 of 00:20:12.589 --> 00:20:16.819 the stuff that's inside the detail view marker. 00:20:16.949 --> 00:20:19.420 The detail view marker is that circular 00:20:19.790 --> 00:20:23.099 line that has two arrows on it pointing to a D, in this case, 00:20:23.349 --> 00:20:24.859 and that line is dashed. 00:20:25.150 --> 00:20:26.459 And that tells us 00:20:26.790 --> 00:20:29.979 that we're gonna zoom in on that area, and it's going to appear 00:20:30.280 --> 00:20:33.579 somewhere else on the drawing, and it's going to tell us something that is 00:20:33.910 --> 00:20:36.109 otherwise hard to look at at the size 00:20:36.459 --> 00:20:38.760 that it exists normally in the drawing. 00:20:39.050 --> 00:20:39.380 OK. 00:20:39.489 --> 00:20:42.640 So, that's what you need to know about assembly drawings 00:20:43.010 --> 00:20:43.640 and 00:20:44.050 --> 00:20:46.560 what you need to know about part drawings. 00:20:46.609 --> 00:20:47.040 So, 00:20:47.579 --> 00:20:49.359 before we leave this whole topic, 00:20:49.449 --> 00:20:51.099 I think it's worth saying 00:20:51.329 --> 00:20:52.199 a few things. 00:20:52.530 --> 00:20:54.849 And item number 1 here is 00:20:55.849 --> 00:20:56.599 I hope 00:20:56.829 --> 00:20:59.859 that when you look at the engineering drawings, they won't look 00:20:59.859 --> 00:21:03.339 as daunting as they did before we had this small discussion. 00:21:03.670 --> 00:21:05.020 But what I hope mostly 00:21:05.270 --> 00:21:07.790 is that you'll actually look at the engineering drawings. 00:21:08.170 --> 00:21:10.849 You need to spend some time with the engineering drawings. 00:21:10.920 --> 00:21:11.329 OK. 00:21:11.369 --> 00:21:14.250 I want to spend 5 to 10 minutes with each of the drawings. 00:21:14.290 --> 00:21:14.400 OK. 00:21:14.410 --> 00:21:15.760 We want to examine 00:21:16.130 --> 00:21:16.599 each 00:21:16.849 --> 00:21:19.880 engineering drawing starting with the title block, 00:21:20.130 --> 00:21:21.319 then with the notes 00:21:21.930 --> 00:21:22.959 on page one. 00:21:23.209 --> 00:21:24.969 Then, we want to look at the views, 00:21:25.180 --> 00:21:28.260 try to understand what the views can tell us and why they're there. 00:21:28.489 --> 00:21:31.130 We want to try to envision the geometry. 00:21:32.150 --> 00:21:35.310 We want to do the same then for all those pages. 00:21:35.719 --> 00:21:37.420 And we wanna look for details 00:21:37.719 --> 00:21:42.650 such as specific dimensions or specific details that maybe 00:21:42.650 --> 00:21:44.640 in a detail view or in a section view. 00:21:45.130 --> 00:21:45.650 OK. 00:21:45.859 --> 00:21:47.569 Just as a final recap on here, 00:21:47.579 --> 00:21:48.609 we're after 00:21:49.060 --> 00:21:51.770 getting good at CAD fluency. 00:21:51.900 --> 00:21:57.170 CAD fluency starts by having a good understanding of why you need to create a model. 00:21:57.540 --> 00:22:01.209 That model understanding can come from a variety of places, 00:22:01.430 --> 00:22:03.219 including talking to a client 00:22:03.500 --> 00:22:04.089 or 00:22:04.550 --> 00:22:07.000 following a product development process for a given company. 00:22:07.395 --> 00:22:10.295 In this case, in this course, we're gonna 00:22:10.295 --> 00:22:13.084 have a number of exercises at the beginning here 00:22:13.375 --> 00:22:17.334 where you create geometry that's conveyed to you in an engineering drawing. So, 00:22:17.334 --> 00:22:20.964 you need to learn how to read those engineering drawings. And this video 00:22:21.375 --> 00:22:22.444 demystified them 00:22:22.694 --> 00:22:23.574 just a little bit 00:22:23.814 --> 00:22:25.685 hopefully making them less daunting, 00:22:26.175 --> 00:22:29.214 something you're willing to engage with and to actually read.