0:00:00.119,0:00:02.150 Reading an engineering drawing is hard. 0:00:02.359,0:00:06.210 It's a foreign language and it takes practice and it takes skill 0:00:06.599,0:00:08.720 to know how to read those engineering drawings. 0:00:09.500,0:00:10.880 In this particular course, 0:00:11.010,0:00:15.600 I know you've been given some complex drawing sets that you need to try to digest. 0:00:15.930,0:00:18.760 It can be frustrating and it is definitely difficult. 0:00:19.049,0:00:20.440 In this particular video, 0:00:20.690,0:00:23.559 I'm gonna take you straight into my iPad and together 0:00:23.770,0:00:27.940 we're gonna look around at the engineering drawing for the NES 0:00:28.569,0:00:32.770 front cover for the Nintendo game controller for the NES system. 0:00:33.110,0:00:35.750 And what I'm going to do is talk through 0:00:36.159,0:00:38.790 how to extract essential information 0:00:39.159,0:00:39.590 from 0:00:39.799,0:00:41.450 the engineering drawing set. 0:00:41.770,0:00:42.110 All right, 0:00:42.279,0:00:44.340 so just pulling a chair up over here, 0:00:44.599,0:00:46.630 looking at the engineering drawing now. 0:00:48.090,0:00:50.979 Any time you have an engineering drawing, 0:00:51.169,0:00:55.409 you've got to spend time actually reading the engineering drawing 0:00:55.750,0:00:58.639 and so what I've what I'm doing right now, 0:00:58.939,0:01:00.450 I'm taking a look at a couple of things, 0:01:00.569,0:01:02.889 maybe I'll highlight where I'm sort of looking. 0:01:03.369,0:01:05.449 First thing I'm doing is I've come down here to 0:01:05.449,0:01:09.620 see how many pages or sheets are in this drawing set 0:01:09.930,0:01:11.650 that's alerting me to 0:01:12.330,0:01:16.199 the extent of the information that I need to be looking for 0:01:16.410,0:01:17.319 and through. 0:01:18.639,0:01:22.709 I'm also taking a look at what's going on up here with the revision block. 0:01:23.239,0:01:27.029 I'm seeing that there was a corrected dimension on a rim groove. 0:01:27.400,0:01:31.550 I like to just know what rev I'm looking at and why I'm looking at it. 0:01:32.120,0:01:32.529 I 0:01:32.680,0:01:36.599 like to start by just sort of glancing through each of the sheets 0:01:37.000,0:01:40.709 and understanding what I might be seeing on each of the pages. 0:01:41.199,0:01:41.750 In this case, 0:01:41.839,0:01:42.279 I 0:01:42.319,0:01:45.440 am seeing the front face and I'm seeing the front face again 0:01:45.970,0:01:49.319 with a bunch of dimensions here for the whole cutouts, 0:01:49.650,0:01:51.919 and then there seems to be this little rim 0:01:52.569,0:01:55.319 that goes around this stuff right here, 0:01:55.610,0:01:57.959 these seem to be defined in this view. 0:01:58.839,0:01:59.739 Right here, 0:02:00.480,0:02:02.720 seeing another cross-section and another note. 0:02:03.930,0:02:04.209 OK, 0:02:04.309,0:02:06.949 on this one, I'm seeing all of the underside 0:02:07.510,0:02:08.139 objects 0:02:08.470,0:02:12.300 as well as having an ISO view here which is helpful, 0:02:12.550,0:02:14.669 so don't have to go all the way back to sheet 1. 0:02:14.990,0:02:17.589 I can see that this page is going to be 0:02:17.949,0:02:21.250 helping me understand how to create these thin-walled 0:02:21.690,0:02:24.229 features that are sort of in these areas. 0:02:25.520,0:02:25.779 OK, 0:02:25.899,0:02:28.690 and then I see there's at least 3 cross-sections here, 0:02:29.020,0:02:31.490 just trying to get a sense for what's in the drawing. 0:02:31.860,0:02:34.529 And then here all these screw bosses, 0:02:34.779,0:02:37.070 this is a screw boss right here by the way, 0:02:37.440,0:02:40.669 all these screw bosses are defined, their location, 0:02:41.139,0:02:42.089 their heights, 0:02:42.460,0:02:42.899 etc. 0:02:45.009,0:02:47.970 And then in the last page of the drawing, 0:02:48.460,0:02:50.009 we have this whole, 0:02:50.300,0:02:52.990 this whole situation that's going on in detail 0:02:53.020,0:02:53.429 'J' 0:02:54.020,0:02:55.529 is being defined out 0:02:55.860,0:02:56.889 on this sheet. 0:02:57.179,0:02:59.619 That's where the cable comes out of the controller. 0:03:00.089,0:03:02.399 And so, I've spent about a minute 0:03:02.699,0:03:04.699 just glancing through these five sheets. 0:03:04.779,0:03:06.339 I have a sense for what's in here. 0:03:06.419,0:03:07.770 I haven't absorbed any 0:03:08.139,0:03:09.300 deep information yet, 0:03:09.380,0:03:10.169 but I have 0:03:10.500,0:03:13.570 checked to just sort of see what is there, 0:03:13.779,0:03:14.130 OK? 0:03:14.259,0:03:18.449 I've also spent a little bit of time glancing at the title block, 0:03:18.899,0:03:20.729 particularly in this area, 0:03:21.539,0:03:23.419 to understand a couple of things. 0:03:23.970,0:03:26.929 This model needs to be created in millimeter units. 0:03:27.250,0:03:29.320 The model material 0:03:29.970,0:03:31.339 needs to be ABS, 0:03:31.649,0:03:33.679 and then there is a texture on it, 0:03:33.770,0:03:35.880 MT11010, 0:03:36.410,0:03:39.000 and there is a color specification that's given. 0:03:39.410,0:03:41.850 So, there's a lot of stuff that's been given right there that's 0:03:41.850,0:03:44.279 going to be essential for me as I create this model, 0:03:44.850,0:03:47.360 especially as I begin the modeling process, 0:03:47.449,0:03:50.529 I've got to absolutely make sure that my units are right, 0:03:51.320,0:03:54.839 that can cause a bit of trouble if I'm starting in inches. 0:03:55.550,0:03:58.240 And then I need to switch this to millimeters. 0:03:59.119,0:04:01.880 The other thing I'm noticing here that's quite helpful for me 0:04:02.279,0:04:06.690 is this data right here that shows what the mass 0:04:06.960,0:04:09.110 of this finished top cover is. 0:04:09.399,0:04:11.460 That's going to be helpful for me as I 0:04:11.839,0:04:14.270 analyze my model and go along, 0:04:15.039,0:04:15.350 during 0:04:15.350,0:04:16.238 the modeling process, 0:04:16.279,0:04:18.070 that's going to be helpful 0:04:18.279,0:04:18.678 to me. 0:04:19.358,0:04:19.760 OK, 0:04:19.880,0:04:23.690 so that's the first part of just sort of absorbing 0:04:24.000,0:04:26.630 an engineering drawing set is just to 0:04:26.959,0:04:28.679 give it a once over, 0:04:29.750,0:04:33.399 then we need to start thinking about how to extract out 0:04:33.829,0:04:37.070 the essential information that's in this drawing. 0:04:37.269,0:04:37.450 Now, 0:04:37.510,0:04:38.600 a couple of tips. 0:04:38.910,0:04:39.959 Item number 1 0:04:40.799,0:04:43.350 is that engineering drawings are often 0:04:44.040,0:04:47.029 created in a sort of hierarchical way, 0:04:47.440,0:04:51.309 meaning that the top level information is on page 1 0:04:51.600,0:04:54.380 and the more detailed information is later 0:04:54.640,0:04:55.559 in the process. 0:04:56.049,0:04:58.350 So, if you're getting started with your model, 0:04:58.630,0:05:03.279 the first CAD modeling steps are likely going to be coming from 0:05:03.279,0:05:06.549 the details found in the first couple of pages of the drawing 0:05:06.799,0:05:08.079 versus the latter 0:05:08.440,0:05:09.170 pages 0:05:09.399,0:05:10.920 or sheets in the drawing. 0:05:11.019,0:05:12.149 So, for example, 0:05:12.440,0:05:17.470 if I was going to start the process of making this model, 0:05:17.799,0:05:20.190 I've got to ask myself some key things like 0:05:20.519,0:05:22.920 what is the overall width and what is the overall height, 0:05:23.000,0:05:24.399 and what is the overall thickness 0:05:25.070,0:05:27.540 of this basic prism 0:05:27.869,0:05:29.899 that this thing is made of? 0:05:31.239,0:05:34.850 Take a look at the drawing now and see if you can extract that out 0:05:35.480,0:05:36.630 in a reasonable 0:05:36.920,0:05:37.390 way. 0:05:38.829,0:05:41.739 What you should be looking for here is 0:05:42.070,0:05:43.380 the largest dimension, 0:05:43.470,0:05:44.700 here is my length. 0:05:45.510,0:05:50.750 My next dimension here is my total sort of height as it would appear in this 0:05:51.630,0:05:51.869 or 0:05:51.989,0:05:52.589 the width, 0:05:52.670,0:05:53.769 I guess we could say 0:05:54.109,0:05:55.100 in this view, 0:05:55.429,0:05:58.140 and then I have the height or the thickness 0:05:58.880,0:05:59.880 of this 0:06:00.239,0:06:02.510 overall part shown right here. 0:06:02.839,0:06:07.950 These three dimensions are essential for me as I get started in my CAD model 0:06:08.320,0:06:10.410 because I'm gonna start by creating 0:06:10.839,0:06:15.700 some chunk of material out of which I will cut out a bunch of holes and other stuff 0:06:16.040,0:06:16.750 like this 0:06:17.239,0:06:19.029 and these three dimensions, 0:06:19.290,0:06:20.119 the width. 0:06:21.000,0:06:21.470 Excuse me, 0:06:21.480,0:06:22.029 the length, 0:06:22.179,0:06:22.829 the width, 0:06:22.920,0:06:23.890 and the height 0:06:24.239,0:06:25.750 are super helpful. 0:06:26.040,0:06:30.920 But I can also notice a really important thing that's going on here and that is that 0:06:31.279,0:06:32.320 we 0:06:32.720,0:06:33.950 have 0:06:36.070,0:06:36.970 basically 0:06:36.970,0:06:37.579 like 0:06:37.779,0:06:38.940 a trapezoidal 0:06:39.470,0:06:40.100 prism 0:06:40.350,0:06:41.220 in this shape. 0:06:41.429,0:06:41.790 In other words, 0:06:41.820,0:06:42.980 they do not have 0:06:43.230,0:06:44.350 vertical walls. 0:06:45.459,0:06:49.779 And this means I'm going to have to start my CAD work in a particular way, 0:06:50.190,0:06:53.190 because the first piece that I wanna pop in here 0:06:54.470,0:06:56.299 that isn't actually going to be 0:06:56.549,0:06:57.670 a rectangular prism, 0:06:57.720,0:07:00.619 it's going to be more like a trapezoidal prism, 0:07:00.910,0:07:02.839 and I have to start to understand 0:07:03.429,0:07:04.329 that shape. 0:07:04.630,0:07:06.779 This is what it looks like from the right side, 0:07:07.170,0:07:09.799 also from the front view right here, 0:07:10.109,0:07:11.619 we're seeing the same thing, 0:07:11.790,0:07:12.010 OK, 0:07:12.109,0:07:13.059 we're seeing a 0:07:13.350,0:07:14.480 trapezoidal 0:07:14.829,0:07:16.589 inward sort of 0:07:17.929,0:07:20.040 slanting to those walls. 0:07:20.209,0:07:21.079 So, this is a really, 0:07:21.320,0:07:24.239 really important bit of information to extract from 0:07:24.570,0:07:25.369 this drawing set. 0:07:25.529,0:07:25.720 Now, 0:07:25.769,0:07:28.609 the major question is how much does it slant in? 0:07:29.480,0:07:29.989 Well, 0:07:30.200,0:07:32.829 we luckily have this detail view right here 0:07:33.119,0:07:37.750 that is telling us that something important is going on in this section, 0:07:38.079,0:07:40.630 and we can go find that in Detail A. 0:07:41.040,0:07:42.040 Let's go find Detail A. 0:07:42.119,0:07:43.190 Here's Detail A. 0:07:44.570,0:07:44.950 And 0:07:45.149,0:07:46.799 Detail A has 0:07:47.290,0:07:48.820 some important information and frankly, 0:07:48.929,0:07:50.760 we need to step back just a second 0:07:51.130,0:07:51.839 and say, 0:07:52.869,0:07:56.700 "One of the first things we have to do whenever we start the drawing, 0:07:56.709,0:07:57.230 reading, 0:07:57.309,0:07:58.019 the drawing, 0:07:58.149,0:07:58.559 the 0:07:58.589,0:08:02.540 reading of the drawing is we need to really pay attention to the notes. 0:08:02.910,0:08:04.420 The notes are there to help, 0:08:04.709,0:08:04.899 like, 0:08:04.910,0:08:07.500 to guide and to give direction and to help, 0:08:07.829,0:08:09.160 you know what 0:08:09.549,0:08:11.970 the creator of the drawing wanted you to know. 0:08:12.470,0:08:13.600 So, we can see, 0:08:13.630,0:08:14.149 for example, 0:08:14.309,0:08:16.299 hidden lines are removed for clarity. 0:08:16.880,0:08:17.609 OK, 0:08:17.809,0:08:20.920 there's a virtual sharp in Detail A that's 0:08:20.920,0:08:23.640 interesting because we're looking at Detail A right now, 0:08:24.049,0:08:27.119 and there's something about detail A that's being told to us. 0:08:27.730,0:08:30.549 General wall thicknesses are shown in section AA. 0:08:30.570,0:08:30.649 Well, 0:08:30.809,0:08:32.400 here's section AA, 0:08:32.820,0:08:33.489 OK? 0:08:33.929,0:08:37.770 And section AA is shown as a slice and not a full cross-section. 0:08:38.258,0:08:39.698 If it was a full cross-section, 0:08:39.739,0:08:40.979 what this would mean 0:08:41.258,0:08:43.129 is that we would actually see 0:08:43.457,0:08:45.658 the rest of the object here 0:08:45.898,0:08:46.939 without a crosshatch, 0:08:47.018,0:08:48.338 but we'd be able to see, 0:08:48.698,0:08:48.818 you know, 0:08:48.939,0:08:51.328 there'd be like posts and some other stuff, 0:08:51.698,0:08:52.098 and it 0:08:52.138,0:08:53.568 would get quite cluttered. 0:08:53.658,0:08:54.568 So, in this case, 0:08:54.939,0:08:55.989 for clarity's sake, 0:08:56.138,0:08:59.208 section AA was provided as only a slice. 0:09:00.539,0:09:01.219 OK, 0:09:01.469,0:09:03.219 now what is a virtual sharp? 0:09:03.299,0:09:03.549 OK, 0:09:03.590,0:09:07.419 we need to go understand what a virtual sharp is. Because a virtual sharp 0:09:07.719,0:09:10.179 is appearing in detail A 0:09:10.510,0:09:12.299 and this is an important 0:09:12.669,0:09:15.979 part of knowing how the trapezoidal prism 0:09:16.270,0:09:17.979 geometry should be made. 0:09:18.469,0:09:20.429 So, this little thing that we have here, 0:09:20.469,0:09:22.700 I'm going to point to it right now before I draw on it, 0:09:22.950,0:09:24.580 that little plus that's there 0:09:24.869,0:09:26.469 is the virtual sharp. 0:09:26.940,0:09:28.330 What this means is 0:09:28.700,0:09:30.890 that if this object 0:09:31.500,0:09:33.109 did not have a fillet 0:09:33.789,0:09:35.080 in its corner, 0:09:35.250,0:09:35.650 right up there, 0:09:35.729,0:09:37.359 there's a fillet right in there. 0:09:37.770,0:09:39.200 It would have a sharp point, 0:09:39.530,0:09:41.280 like what we're seeing right over here. 0:09:41.570,0:09:43.359 And that sharp point 0:09:43.690,0:09:46.010 would be something that could be dimension too. 0:09:47.530,0:09:50.690 And when that sharp point goes away, 0:09:51.020,0:09:54.820 such as when there's a filet that's added to something like this, 0:09:57.020,0:09:57.549 then 0:09:57.760,0:09:57.810 a 0:09:57.760,0:09:59.750 marker can go right here. 0:10:00.000,0:10:02.070 Let's see if I can switch this color 0:10:02.520,0:10:03.340 and 0:10:03.640,0:10:05.190 make this even more obvious, 0:10:05.640,0:10:06.190 OK? 0:10:06.520,0:10:11.179 Then a marker can go right there exactly where the sharp point would have been, 0:10:11.479,0:10:11.820 therefore 0:10:11.840,0:10:13.609 it is called a virtual sharp. 0:10:13.919,0:10:16.150 That can be valuable because 0:10:16.440,0:10:18.289 if we want to dimension 0:10:18.960,0:10:19.719 to that 0:10:20.210,0:10:22.179 we can and we do the dimension to 0:10:22.179,0:10:24.890 the virtual sharp and that's actually what's going on 0:10:25.250,0:10:25.729 right here. 0:10:25.849,0:10:28.000 This 0.85 typical 0:10:28.369,0:10:30.590 is going to this virtual sharp. 0:10:30.849,0:10:32.280 That helps us to know 0:10:32.650,0:10:33.770 what size 0:10:36.349,0:10:37.820 that trapezoidal prism 0:10:38.070,0:10:39.099 is made at. 0:10:39.729,0:10:39.869 All right, 0:10:40.039,0:10:44.549 so I'm seeing those 3 or 4 critical dimensions that help 0:10:44.549,0:10:48.419 me get my first chunk of material into the CAD system. 0:10:49.070,0:10:52.580 Once I have that basic chunk of material into the CAD system, 0:10:52.909,0:10:55.739 it's a matter of me starting to chip away 0:10:56.030,0:10:57.200 at producing 0:10:57.549,0:10:59.940 the geometries associated with that. 0:11:00.500,0:11:00.940 So, 0:11:01.140,0:11:01.809 I 0:11:01.820,0:11:03.099 can see that 0:11:03.619,0:11:04.890 because there is 0:11:05.340,0:11:07.609 some attempt to describe, 0:11:07.780,0:11:09.530 I'll switch colors here for a second, 0:11:09.780,0:11:13.729 there's some attempt to describe a general wall thickness, 0:11:14.140,0:11:17.049 it's most likely that a shell is used 0:11:17.380,0:11:18.780 somewhere in this set, 0:11:18.820,0:11:21.469 because the shell gives us a nice constant 0:11:21.909,0:11:26.390 wall thickness, and I can see that the wall thickness is shown in section AA, 0:11:26.780,0:11:27.539 (whereas it's shown), 0:11:27.580,0:11:28.650 it's right here. 0:11:29.520,0:11:30.119 OK. 0:11:31.159,0:11:33.429 If we're going to look at something that's called general. 0:11:34.909,0:11:36.940 Then we're gonna look for something that's called typical 0:11:38.000,0:11:39.840 because typical 'TYP' 0:11:40.200,0:11:41.140 means that 0:11:41.510,0:11:42.940 this same thickness 0:11:43.510,0:11:44.349 that's here 0:11:44.669,0:11:49.669 also exists here, and also exists here, and also exists here, and also exists here, and 0:11:49.989,0:11:51.280 here, and here 0:11:51.869,0:11:52.400 and 0:11:52.549,0:11:53.309 throughout. 0:11:54.229,0:11:55.700 It's a little different over here, 0:11:55.780,0:11:56.200 but 0:11:56.460,0:11:57.369 nevertheless, 0:11:57.739,0:11:58.619 everywhere 0:11:59.450,0:12:02.039 in those areas, we would have constant wall thickness. 0:12:02.109,0:12:02.469 So, 0:12:02.950,0:12:03.669 what have I done? 0:12:03.750,0:12:05.270 I have gone into my drawing. 0:12:05.309,0:12:09.299 I've tried to figure out how am I going to create my first basic shape. 0:12:09.789,0:12:12.940 I've looked at the drawing to pick out 0:12:13.299,0:12:16.869 the, the dimensions that are most likely the 0:12:16.869,0:12:19.659 ones that I need to create that basic geometry. 0:12:20.270,0:12:20.619 Now 0:12:20.960,0:12:22.119 it's worth knowing 0:12:22.590,0:12:26.299 that there's a lot of information here that's not needed yet. 0:12:27.280,0:12:27.520 OK, 0:12:27.599,0:12:30.950 so I'm trying to build out my basic trapezoidal prism. 0:12:31.299,0:12:33.520 There's some stuff I just don't have to worry about, 0:12:33.559,0:12:33.799 OK? 0:12:33.840,0:12:35.429 I don't have to worry about, 0:12:35.719,0:12:36.000 you know, 0:12:36.119,0:12:36.880 this dimension, 0:12:36.940,0:12:37.440 for example, 0:12:37.479,0:12:38.630 or this dimension. 0:12:38.919,0:12:40.590 Those are going to come later. 0:12:40.880,0:12:42.799 And the reason why this is important is because 0:12:42.799,0:12:45.750 there's a lot of information on these drawing sets 0:12:46.140,0:12:46.750 and 0:12:47.200,0:12:49.479 you have to be able to start to pick out what 0:12:49.479,0:12:53.010 is the important information and what is the not important information 0:12:53.320,0:12:55.239 for the given step that you're working on. 0:12:55.630,0:12:59.539 And if you had a CAD strategy and your CAD strategy looked something like this, 0:12:59.880,0:13:01.190 like you're going to 0:13:01.830,0:13:04.950 draw one plane and then I'm gonna switch colors here for a second. 0:13:05.119,0:13:07.030 You're gonna draw another plane like this, 0:13:07.200,0:13:07.700 OK? 0:13:08.070,0:13:11.020 And then you are going to extrude between them 0:13:11.280,0:13:14.270 and create some sort of trapezoidal prism. 0:13:14.559,0:13:17.510 You would need to know how to first draw 0:13:18.200,0:13:21.559 one of those sketches and then how to draw the other sketch, 0:13:21.900,0:13:23.630 and what those dimensions would be. 0:13:23.710,0:13:23.950 So, you're 0:13:25.010,0:13:27.789 looking for those in the drawing set. 0:13:28.719,0:13:29.349 All right, 0:13:29.479,0:13:30.229 now, 0:13:30.559,0:13:31.330 what 0:13:31.729,0:13:32.719 else 0:13:32.799,0:13:33.840 should we say about this, 0:13:33.880,0:13:34.510 OK? 0:13:37.260,0:13:38.609 It's important to know, 0:13:38.940,0:13:40.390 while you are 0:13:40.780,0:13:44.489 looking around drawings for particular bits of information, 0:13:44.820,0:13:47.530 there's a couple of rules that you should know about. 0:13:47.979,0:13:48.780 Number one, 0:13:50.409,0:13:50.609 well, 0:13:50.770,0:13:53.000 we don't have any hidden lines on this drawing, 0:13:53.010,0:13:55.250 and that's actually good for you right now, 0:13:55.669,0:13:55.909 but 0:13:56.010,0:13:58.039 you should know that 0:13:58.130,0:14:01.369 you're not allowed to dimension to hidden lines on drawings. 0:14:01.450,0:14:03.640 This is part of the ASME standards. 0:14:03.890,0:14:06.440 You're not allowed to dimension to a hidden line, 0:14:06.729,0:14:08.450 and that would mean that if I wanted to know, 0:14:08.510,0:14:09.400 for example, 0:14:09.729,0:14:11.640 how tall is this post? 0:14:12.049,0:14:14.010 Can we go look at the isometric view for a 0:14:14.010,0:14:15.570 second so we can know what we're talking about. 0:14:15.700,0:14:17.609 I want to know how high is that post. 0:14:18.289,0:14:21.450 There's only one way for me to know this in this drawing set 0:14:21.450,0:14:23.840 and that is that I have to look for a cross-section, 0:14:24.130,0:14:24.530 OK? 0:14:24.609,0:14:27.520 And so, let's go see if we can find that cross-section. 0:14:27.809,0:14:27.909 Well, 0:14:27.929,0:14:29.840 there's a cross-section B right here. 0:14:30.760,0:14:31.239 OK, 0:14:31.479,0:14:34.039 this is cross-section B and there's no post in that one, 0:14:34.080,0:14:35.280 so that's not gonna be it. 0:14:35.950,0:14:36.190 OK, 0:14:36.270,0:14:38.270 here's some other cross-sections here, 0:14:38.650,0:14:38.750 but 0:14:38.869,0:14:41.270 none of them go through the post I was wanting, 0:14:41.309,0:14:42.260 which was that one. 0:14:42.929,0:14:43.419 OK. 0:14:43.909,0:14:45.450 So that's a little bit 0:14:45.450,0:14:46.059 difficult. 0:14:52.349,0:14:52.450 See 0:14:52.450,0:14:54.059 what else we have going on here. 0:14:55.049,0:14:55.599 OK? 0:14:56.849,0:14:57.020 "Oh, 0:14:57.030,0:14:57.230 here 0:14:57.230,0:14:57.710 we go. 0:14:58.090,0:14:59.320 Section-F 0:15:00.049,0:15:02.929 goes right through the exact post that I want, 0:15:03.330,0:15:04.919 and here's section-F. 0:15:05.820,0:15:06.450 Right here, 0:15:06.580,0:15:08.250 and it is telling me 0:15:08.539,0:15:09.770 the height of that post, 0:15:09.979,0:15:12.979 the height of that post is 5.68. 0:15:14.150,0:15:14.309 All right, 0:15:14.380,0:15:16.150 the height of that post is 5.68. 0:15:16.390,0:15:17.750 Another thing you should know about drawings 0:15:17.750,0:15:20.780 is you're extracting information from drawings, 0:15:21.070,0:15:22.299 and that is 0:15:22.669,0:15:23.299 that 0:15:23.710,0:15:24.820 lines that, 0:15:25.070,0:15:25.510 for example, 0:15:25.559,0:15:26.469 I'm gonna look right in here, 0:15:26.570,0:15:27.010 OK? 0:15:27.349,0:15:30.039 Lines that appear to be right angles 0:15:30.469,0:15:33.030 are assumed to be right angles, 0:15:33.150,0:15:34.549 that's supposed to be 90, 0:15:34.669,0:15:34.989 OK. 0:15:36.429,0:15:36.650 Lines 0:15:36.650,0:15:39.590 that appear to be on the same line 0:15:39.789,0:15:40.869 such as this 0:15:42.169,0:15:44.640 are actually on the same line. 0:15:45.359,0:15:47.679 And these are important things to know about drawing. 0:15:47.750,0:15:48.729 So, for 0:15:48.729,0:15:49.059 example, 0:15:50.190,0:15:50.619 because, 0:15:50.789,0:15:53.340 let's see if I can undo that one that I just did, 0:15:53.599,0:15:53.979 OK. 0:15:54.309,0:15:54.619 The 0:15:54.830,0:15:56.940 height of this post 0:15:57.309,0:15:58.460 is this much 0:15:58.830,0:16:02.500 and the height of that post is also that same amount, 0:16:02.869,0:16:07.900 5.68, because they appear to be on the same line, 0:16:08.530,0:16:08.739 OK? 0:16:08.979,0:16:11.140 Same thing goes with lines that are flat 0:16:11.390,0:16:12.070 appear to be flat 0:16:12.150,0:16:13.309 are actually flat, 0:16:13.669,0:16:16.169 and all that kind of wonderful stuff. 0:16:16.539,0:16:16.739 OK, 0:16:16.840,0:16:18.940 what else do we need to know about this? 0:16:19.219,0:16:20.489 We need to know that 0:16:20.780,0:16:23.090 there are some symbols on here that 0:16:23.239,0:16:24.570 need to be described. 0:16:24.859,0:16:25.020 OK. 0:16:25.130,0:16:26.659 This is a complex one, 0:16:26.700,0:16:27.299 for example, 0:16:27.390,0:16:28.020 OK? 0:16:28.179,0:16:29.950 This means that there are 6 0:16:31.250,0:16:36.549 features that have a diameter of 1.44, 0:16:36.960,0:16:38.760 see if we can think about what that is, 0:16:39.049,0:16:39.650 there's 1, 0:16:39.849,0:16:40.640 there's 2, 0:16:40.729,0:16:41.479 there's 3, 0:16:41.530,0:16:42.210 there's 4, 0:16:42.349,0:16:42.960 there's 5, 0:16:42.969,0:16:44.039 and there's 6. 0:16:44.330,0:16:46.109 How do I know that those are the ones? 0:16:46.530,0:16:48.320 Because when you come over here and you look at this, 0:16:49.010,0:16:51.080 all 6 of those look similar. 0:16:51.729,0:16:51.900 OK, 0:16:51.929,0:16:55.210 I got to get back to sketching and not erasing 0:16:55.489,0:16:55.890 that one, 0:16:55.969,0:16:56.440 that one, 0:16:56.570,0:16:57.090 that one, 0:16:57.250,0:16:57.830 that one, 0:16:57.849,0:16:59.690 and that one and that one. 0:17:00.239,0:17:02.830 All appear similar. And in this 0:17:03.520,0:17:06.670 drawing image they also all appear similar 0:17:07.040,0:17:10.209 and the fact that there's a dimension that says 6X 0:17:10.560,0:17:11.329 means 0:17:11.800,0:17:12.630 that they are. 0:17:12.959,0:17:15.108 Now what does this symbol here mean? 0:17:15.560,0:17:18.329 This means that there is a hole, 0:17:18.880,0:17:20.300 and it's pointing to a hole, 0:17:20.520,0:17:20.739 OK, 0:17:20.800,0:17:22.750 you can see it pointing right there to that hole. 0:17:23.000,0:17:24.510 This hole that's right here 0:17:25.239,0:17:25.989 is 0:17:26.329,0:17:29.089 5.68 millimeters deep. 0:17:30.119,0:17:30.390 Now, 0:17:30.439,0:17:34.069 if we couple that together with what we saw in the cross-section, 0:17:34.760,0:17:36.229 we can actually see that hole, 0:17:36.359,0:17:37.229 it's right there. 0:17:38.060,0:17:38.260 OK, 0:17:38.270,0:17:40.569 it goes all the way down right there and it 0:17:40.859,0:17:42.849 is in line with this. 0:17:43.180,0:17:46.020 And so, we know actually that we've interpreted that 0:17:46.500,0:17:47.209 correctly. 0:17:47.459,0:17:49.369 Let's see if there's anything else in here that's 0:17:49.540,0:17:52.089 interesting to talk about right now 0:17:52.500,0:17:53.410 other than 0:17:53.900,0:17:56.030 the stuff we have already talked about. 0:17:56.300,0:17:57.890 I think this is a good one right here. 0:17:57.939,0:17:59.500 Let's take a look at this for a minute. 0:18:01.069,0:18:03.420 Maybe this drawing has more than one that will help us, 0:18:03.469,0:18:03.670 OK, 0:18:03.790,0:18:04.390 this is good. 0:18:05.150,0:18:07.310 There are two things going on on this drawing that 0:18:07.310,0:18:09.709 are on this view that are worth thinking about. 0:18:10.069,0:18:11.900 One is the fact that sometimes 0:18:12.109,0:18:13.459 8X is used 0:18:13.910,0:18:16.280 and sometimes a thing called typical is used. 0:18:16.349,0:18:17.819 'TYP' means typical. 0:18:18.229,0:18:18.349 Well, 0:18:18.430,0:18:20.260 we already know the 8X version of this. 0:18:20.329,0:18:22.469 It means that there's 8 radii 0:18:23.300,0:18:24.800 of the same exact 0:18:25.099,0:18:25.890 size, 0:18:26.300,0:18:29.410 and they should be easily pick out a ball 0:18:29.819,0:18:30.770 in this drawing. 0:18:30.979,0:18:31.420 There's 1, 0:18:31.459,0:18:31.819 there's 2, 0:18:31.939,0:18:32.339 there's 3, 0:18:32.420,0:18:32.780 there's 4, 0:18:32.859,0:18:33.260 there's 5, 0:18:33.339,0:18:33.699 there's 6, 0:18:33.780,0:18:34.180 there's 7, 0:18:34.260,0:18:34.969 there's 8. 0:18:35.260,0:18:38.530 All 8 of those are 1.3. 0:18:39.020,0:18:40.140 But over here, 0:18:41.130,0:18:42.849 we have something different going on, 0:18:42.920,0:18:43.430 OK? 0:18:43.709,0:18:44.849 We don't have 0:18:45.219,0:18:47.890 a certain number, 0:18:48.180,0:18:48.380 you know, 0:18:48.500,0:18:52.420 like 12X or something in front of this 1.00. 0:18:52.500,0:18:55.410 We instead just have 1.00 typical. 0:18:55.800,0:18:56.969 Why is that the case? 0:18:57.339,0:18:57.540 Well, 0:18:57.699,0:18:59.170 if we take a look at this guy, 0:18:59.500,0:18:59.579 OK, 0:18:59.660,0:19:02.530 and let's go erase some of this stuff that I had on here earlier. 0:19:03.219,0:19:03.300 OK, 0:19:03.339,0:19:04.260 if we look at this guy, 0:19:04.380,0:19:05.939 I'm gonna turn this one to blue for a minute. 0:19:06.400,0:19:13.270 I've got 1-2-3-4-5-6-7-8-9- 0:19:13.280,0:19:14.359 10-11- 0:19:14.369,0:19:15.430 12, 0:19:15.959,0:19:17.619 but then I also have 0:19:18.300,0:19:19.349 this one in red 0:19:19.640,0:19:21.150 13-14- 0:19:21.160,0:19:22.550 15-16- 0:19:22.560,0:19:23.640 17-18- 0:19:23.650,0:19:24.989 19-20. 0:19:25.400,0:19:29.800 20 geometric features that have a dimension of 1, 0:19:30.359,0:19:32.949 just in this particular part of the image. 0:19:33.420,0:19:35.910 And so, the way that that's dealt with is not 0:19:36.199,0:19:36.939 to say, 0:19:37.160,0:19:37.239 well, 0:19:37.280,0:19:38.079 what number did I say? 0:19:38.119,0:19:38.400 I don't know, 0:19:38.439,0:19:39.540 is it 16. 0:19:40.130,0:19:40.160 No, 0:19:40.199,0:19:41.150 it was 20. 0:19:41.869,0:19:43.550 It's not to do this. 0:19:45.800,0:19:46.709 But instead, 0:19:46.880,0:19:50.050 it's to say 1.00 TYP. 0:19:50.939,0:19:54.219 Because it's more obvious that that's what's going on 0:19:54.579,0:19:55.699 in this area. 0:19:57.670,0:19:58.319 OK, 0:19:58.589,0:19:59.459 erasing those. 0:20:00.410,0:20:00.430 All right, 0:20:01.119,0:20:01.329 what 0:20:01.400,0:20:03.000 else do we need to talk about? 0:20:03.160,0:20:05.790 It's important to know that circles 0:20:06.199,0:20:08.189 will always be designated 0:20:09.079,0:20:12.910 by the standards as a diameter and arcs, 0:20:13.239,0:20:14.339 not complete circles, 0:20:14.369,0:20:16.680 will always be designated by a radius. 0:20:17.459,0:20:20.469 It's also important to know that in engineering drawings, 0:20:20.479,0:20:21.949 according to the standards, 0:20:22.319,0:20:27.300 circles will only be dimensioned where they look like a circle. 0:20:27.630,0:20:28.739 So, if I had a shaft, 0:20:28.750,0:20:29.219 for example, 0:20:29.349,0:20:30.540 that looked like this, 0:20:31.189,0:20:33.819 and I had an engineering drawing that looked like this, 0:20:34.869,0:20:37.540 I would dimension this one 0:20:37.910,0:20:39.020 in this view, 0:20:40.209,0:20:40.660 not 0:20:40.790,0:20:41.589 like this. 0:20:42.849,0:20:43.150 OK, 0:20:43.270,0:20:45.459 this one is diameter something. 0:20:45.709,0:20:46.979 This is no good. 0:20:47.270,0:20:50.500 And the reason why I'm telling you that is because as you look for information, 0:20:50.750,0:20:52.020 you want to make sure 0:20:52.270,0:20:53.479 that you 0:20:53.869,0:20:54.420 are 0:20:54.680,0:20:55.939 looking in the right spot. 0:20:56.030,0:20:58.069 So, if you're looking for the dimension of a circle, 0:20:58.150,0:20:59.979 look where it actually appears 0:21:00.349,0:21:00.810 like 0:21:01.069,0:21:01.859 a circle. 0:21:02.270,0:21:02.739 OK, 0:21:02.859,0:21:05.430 a few things I want to just go over here for a second. 0:21:06.969,0:21:10.569 As you're trying to extract out the information from these drawings, 0:21:10.790,0:21:12.560 (let me just zoom out here for a second). 0:21:15.010,0:21:16.280 We want to start 0:21:16.609,0:21:21.640 by getting an overall view of the drawing by just scanning through it, 0:21:22.349,0:21:24.020 understanding what images are there, 0:21:24.290,0:21:26.280 trying to absorb a little bit of stuff, 0:21:26.449,0:21:26.839 OK? 0:21:27.209,0:21:28.979 We want to take a look at the title block, 0:21:29.130,0:21:30.920 see what information is given there. 0:21:31.209,0:21:33.000 We definitely want to read the notes, 0:21:33.489,0:21:33.920 OK? 0:21:34.410,0:21:37.920 And then we want to start getting the top level information 0:21:38.160,0:21:39.270 that will help us 0:21:39.609,0:21:42.719 to start building out the geometry. 0:21:43.089,0:21:43.569 OK. 0:21:45.079,0:21:45.279 While 0:21:45.279,0:21:46.229 you're doing this, 0:21:46.359,0:21:49.680 you want to learn to look for clues 0:21:50.239,0:21:51.500 in the drawing, 0:21:51.520,0:21:53.880 and I don't mean this from an educational perspective. 0:21:53.920,0:21:56.109 I just mean that there are certain things like 0:21:56.599,0:21:59.479 general wall thickness that's going to tell you 0:21:59.479,0:22:01.270 there's going to be a shell somewhere, 0:22:01.560,0:22:02.040 right? 0:22:02.280,0:22:02.829 Or 0:22:03.170,0:22:04.219 there are 0:22:04.520,0:22:08.969 things like these virtual sharps that we saw here that mean that 0:22:09.319,0:22:14.030 really we're trying to give a dimension before a radius would occur in a CAD model, 0:22:14.280,0:22:14.400 right, 0:22:14.410,0:22:16.829 or before a radius occurred in a manufacturing 0:22:17.310,0:22:17.719 step. 0:22:18.609,0:22:18.920 Also, 0:22:19.910,0:22:19.985 we 0:22:19.985,0:22:21.390 want to take a look at the cross-sections. 0:22:21.689,0:22:24.439 We want to know that the cross-sections are there to help us 0:22:24.729,0:22:26.959 and we want to really try to absorb the cross 0:22:26.959,0:22:30.170 sections and understand what's going on with the cross-sections. 0:22:30.329,0:22:32.800 Then we want to do our best to soak in the details 0:22:33.089,0:22:34.619 of the detail view, 0:22:34.930,0:22:35.170 right? 0:22:35.290,0:22:36.760 What is this telling us? 0:22:36.810,0:22:38.760 This is an interesting one right here, 0:22:38.969,0:22:39.219 OK? 0:22:39.489,0:22:39.859 Because 0:22:40.489,0:22:41.439 this line 0:22:41.930,0:22:43.140 and this line 0:22:43.619,0:22:47.719 are parallel to each other and this line and this line are parallel to each other. 0:22:48.010,0:22:49.479 This is interesting because 0:22:49.969,0:22:51.979 there are other ways 0:22:52.369,0:22:53.199 to 0:22:53.609,0:22:55.280 have measured this. 0:22:55.479,0:22:55.489 Yeah, 0:22:55.500,0:22:56.800 we did this one and this one, 0:22:56.979,0:22:57.329 OK? 0:22:58.239,0:23:00.109 We could have measured like this, 0:23:00.280,0:23:02.790 and these give us two different numbers actually, 0:23:03.040,0:23:05.949 and this is something that can cause trouble in this particular 0:23:06.359,0:23:06.930 model. 0:23:07.680,0:23:08.439 So, 0:23:09.390,0:23:09.510 understand 0:23:09.510,0:23:10.229 what 0:23:10.520,0:23:12.469 these things are telling you, 0:23:12.719,0:23:13.239 OK? 0:23:13.680,0:23:14.469 Also, 0:23:16.079,0:23:16.175 most 0:23:16.175,0:23:16.839 important, 0:23:16.920,0:23:20.650 I think as you're looking through these engineering drawings is just to realize 0:23:21.020,0:23:22.829 that the information is there. 0:23:23.199,0:23:25.709 You don't need all of it at once. 0:23:26.060,0:23:28.390 You need to use your CAD strategy 0:23:28.719,0:23:31.839 to help you know just what bit you need, 0:23:32.199,0:23:35.150 what feature you want to create so that you can get into this 0:23:35.510,0:23:38.050 set of drawings and go find the essential 0:23:38.439,0:23:39.430 dimensions 0:23:39.680,0:23:41.359 that will help you get it. 0:23:41.959,0:23:43.849 So, I'm coming back now to 0:23:44.130,0:23:46.449 just sort of end of this and say that it 0:23:46.449,0:23:49.849 is indeed really hard to read these engineering drawings. 0:23:50.010,0:23:52.439 It is a foreign language in my view 0:23:52.650,0:23:53.760 and it takes practice. 0:23:53.810,0:23:54.650 It takes 0:23:55.010,0:23:55.780 patience 0:23:56.130,0:23:57.719 and it takes a willingness 0:23:58.130,0:24:00.040 to actually read them, 0:24:00.329,0:24:01.680 and to try to 0:24:02.130,0:24:05.420 see what they're telling you, and to envision the geometry 0:24:05.689,0:24:07.040 that's being described. 0:24:07.329,0:24:08.410 And as you do that, 0:24:08.959,0:24:10.579 your mind will be able to 0:24:10.880,0:24:12.719 notice certain dimensions, 0:24:13.599,0:24:14.689 certain features, 0:24:14.959,0:24:15.800 certain patterns, 0:24:15.880,0:24:16.790 certain other things 0:24:17.040,0:24:17.869 that will help you 0:24:18.160,0:24:20.270 during the CAD modeling process.