 Alright, this is an example on section. So, what I have at the top is a solid and what I would want to do is I would want to section the solid using a vertical plane that passes through the center of the solid and I would want to show this part of the solid in section. And I would want to show that in the front view. So, the viewing direction is this and of course, I will be also drawing the top view. So, I have made certain modifications in the dimensions over here. So, this dimension initially was 43, now it is 38, this dimension was 16, I have taken that as 14 and the height of this base from this platform or the other way around the height of the platform from this base is about 3 millimeters. So, this time I am already prepared with the sketch. So, what I have over here is top view and this is the sectional front view. I have also marked certain important dimensions this time in my sketch. So, that while I am transferring this drawing onto my sheet, I try to do this as efficiently as possible. One thing that you would want to note is the way I have dimensioned this in a circle. This is probably not a good idea, because none of the lines should be appearing within the hashed region, be it the center line, be it the solid line or be it the hidden line. For that matter even this part of the center line and this part of the center line, the presence of these center lines or these parts of center lines is not a good idea. What I will do is I will transfer this drawing on my sheet here in 1 is to 0.5 scale, that is I will double the size of what I have on the sheet, on my sketch sheet over here. So, that hopefully the object looks better. Once again introducing my friends, this is my 2 H pencil, this is my H pencil and this is my colored pencil blue in color, which I have not used so far. My 2 friends the set squares, which I do not think I will be using for this example. So, I will keep them aside and of course, my stencil of circles, which I might use depending on whether I have these circles in here or not. Of course, my compass, so with my friends with me I will start drawing. Once again it is always a nice idea for me to get an idea of where my drawing is going to be. So, I will start with the bounding boxes. I will first draw the top view and then later the front view, because hatching would take some time. Top view seems a little easier for this example. So, this overall dimension is about 128 millimeters, twice of that is 256. I have my scale here, this is about 25, maybe I will need a little more. So, and then this is about 43, twice of that is 86. So, maybe I will shift a little up and left I will draw the horizontal of the bounding box. This is about 24 millimeters and perhaps 2 more millimeters from here. I forgot to check if my graph was set alright or not. I should have done that. Now, that I have done that I will need to use this friend of mine. I have been telling you all not to be using this friend, but you know at times he is very handy my sheet looks as fresh as it was before alright. So, 256 millimeters possibly from here 0 to 24, 2 more millimeters from here. I am intentionally drawing dim lines. Hopefully you can see that, if you cannot maybe I will darken it a little. I will use the back side of my horizontal scale for that perhaps this is. And then the vertical dimension is 86 over here perhaps, maybe a little dark not too dark just little dark 86 from here till here perhaps, gentle vertical line. Again using the back side of the drafter I make this horizontal line. It is just about double the size of the top view here. While I am working with the bounding boxes it may be a nice idea for me to draw one for the front view as well. Where I am going to be drawing the section front view I will have to using the projections need to make sure I have enough gap between the total block and this horizontal construction line. Always a good idea to have gaps because they bring neatness to one's drawing. So, this dimension here is 48, 48 times 2 is 96. I think I would have that cover to see this line better I use the back side of the drafter. So, let me start with the top view getting that is not a problem. I have pretty much all the features covered up. Let me start from the right hand side. So, it is symmetric as you would observe. So, there would be a center line passing through the center of this bounding box. Let me draw that first. This would be at 43 from below possibly here let me double check. So, I have marked the center of this bounding block or bounding box at these two vertical edges. I use my horizontal side of the drafter and straight away with my edge pencil draw the center line. Long dash, short dash, long, short this should suffice. Maybe this part of the drawing is little lighter perhaps I can go over this line once again. Now, from the other side or maybe I will just let go of this. So, starting from right hand side this is about 22 plus that is 44. So, I would need a compass and I need to measure this radius as 22. So, I will mark my pencils over here mark this is 22 pretty much over here pretty much over here and let me also draw this center line and maybe this time little darker. Then using my compass bring this a center making sure that is meeting both these points. Let me double check of this dimensions alright looks like it is while I am at it I will extend this center line looks like I am pretty much and then we will be starting from the bottom can you form pressure I draw this arc I will do that one more time possibly the third time from the other side looks good. Now, for the bigger arc. So, this is about 38 half of that is 19. So, in this sketch this is 19, but twice of that is 38. So, I would need this dimension 38 pretty much over here. So, this is 5 mm from the bottom edge maybe what I can do is I can do the same thing 5 mm from the bottom edge I can mark this point spread my compass little same center larger radius. So, notice that I am drawing got 1 is to 0.5 scale drawing. So, I am virtually magnifying this entire figure to scale 2 hands are little shaky, but I guess I have this curve once I have this I may be join these straight lines. So, remember that solid lines they get precedence over center lines. So, I can take advantage of that maybe I can go left and try to work out this feature. So, from here to here is about 79 1 less than 80 twice of that is 2 less than 160. So, 2 less than 160 is about 158 mark this point over here and I have this center line. So, maybe I will go ahead and straight out make a center line at this position while I am at it I might as well project this center line here I forgot to switch my pencil I should have taken a 2 h pencil. And while I am working on the construction lines I might as well project this part down below perhaps this part down below. So, this vertical line is solid I know that. So, I take my h pencil and straight away draw a dark line supporting the vertical scale of my drafter probably there I go I have marked this center I need to be careful. So, between this and this center line there is a gap of 25 twice of that is 50. So, maybe I will mark 50 from here get this switch my pencil and perhaps draw this center line. Now once again using my solid 2 h by now you would have figured the convention for representing the center line. Now, if you look at this area. So, we have a counter bow here. So, there is a hole which is of diameter 25 which is drilled through and then there is another counter board hole which is of diameter 35 and which is 5 deep on both sides. So, let me first draw this outer feature and then go to the inner one 5 35 double of that have to measure 35 on both sides maybe I should be using this on the line marking these points on the line use a projection to mark these points here these points here this point here and then I will go. So, this is 5 deep twice of that is 10. So, I perhaps go 10 deep and from here maybe I will go 10 deep towards me now these are dashed lines I am going to make them dashed hidden lines maybe I will extend this a little try to make sure that I draw small dashes as opposed to long ones and then the vertical dashes pretty much done. So, this would be a solid line and there is an arc here. So, I need to be a little careful the center of this arc is same as this well. So, from till here I can make this line solid maybe let me work on the bottom horizontal line probably this object is taking time because I am drawing this in 1 is to 0.5 scale that is I am magnifying the views by 2 anyhow. So, I have pretty much all these features ready except for well now not quite. So, let me also work on these vertical dashed lines looking at this through hole the inner diameter is 525. So, measure 25 from both ends draw vertical dashed lines short dashes alright maybe it is time for me to draw this smaller circle this is of diameter 14 let me make sure that the lower surface of this stencil is clean. So, that it does not spoil my sheet go up there I look for a circle with diameter 28 reminding myself that I am still working on a double figure looks like I have my center lines aligned with these 4 lines would not be very accurate, but I will do the job importantly I will get a much better looking circle this is one thing that happens when you use an eraser need to continuously wipe your sheet. Now, for the larger curve here radius is pretty much well known take this center this would be my radius pretty much make sure that I reach this point as well looks like I do just a little away from that point I draw this arc and I truncate this arc little before the other point let me draw this again and perhaps I can do a photoshop touch looks like I am good have I done pretty much everything in the top view yes except for these horizontal lines and the rib let me work on the rib first. So, this is 10 thick twice of that is 20 let me measure 10 on both sides I have to be a little careful and here 10 here let me take this pencil away compass away I first draw the rib change the pencil first edge of the rib perhaps the second edge of the web looks pretty much ok and what remains now these horizontal edges which are distant 38 from each other and symmetrically plays about the horizontal axis. So, I will probably have to go 38 up and 38 down. So, 38 up change my pencil much over here perhaps and 38 down well on second thought I do not need to make those measurements because I already have these features which from which I can take the horizontal line perhaps I can take one from here support my drafter and then I can take one from the top looks like I am done now if you look at this object over here. So, this horizontal platform is kind of tangent to this part of the surface. So, maybe it would not be. So, this platform this horizontal edge would not be hitting the cylindrical part of the object here it would not be hitting it hard. So, maybe I can just you know give it a little touch. So, that is tangential a minor flick of the pencil on the paper done with the top view now getting on to the front view which is the more important part because this where the details are of the hidden feature before I do that well I will come to that later with the front view now. Maybe it will be a nice idea for us to cover the complex part of the front view to start with and then walk on the simpler part. So, this is a semi circle of radius 24 here it will be radius 48 it is again placed symmetrically about the horizontal and the vertical well in this local region. So, let me draw the center vertical center first vertical center line first this distance is about 48 plus that is 96. So, maybe I will measure 48 from here I keep reminding myself to switch the pencil and I draw this part of the center line the horizontal part you know what maybe it was not a nice idea for me to draw this extended center line because I know that I will be hatching the rest of the portion around it. So, what I will do is I will erase a major part of the center lines and I am using my eraser in such a way that I do not leave an impression of the lines that I had just drawn well with a careful eye you would be able to see that, but once I wipe the surface once I wipe the sheet probably to you would given to you it will not be visible. See I do not think it is visible to you nevertheless let me first draw this circle this is of diameter 25 I will have to use my compass I cannot do with my stencil anymore because I need 1 of diameter 50 mark my radius first then draw the circle this is tricky part I will have to be careful I hope I am doing this right no I am not doing this right I am drawing a circle of 35 I should be drawing 1 of 25 I will be using my eraser again I seem to be making quite a few mistakes today 25 here 25 here contract my compass a little bit to get this dimension and it looks like I am ok from both sides. So, maybe I will start from here finish this circle once again I try to give as uniform pressure as I can much nicer to draw them on the screen than on the sheet now that I have my circle maybe I can extend the center lines just about to the periphery of the circle the vertical ones and possibly the horizontal ones as well. So, I have gotten this part right to get these vertical lines and the corresponding center line I can use the projection coming up from here remember for construction lines I use 2 H and maybe I can draw these edges using my H pencil directly because I know that they are going to be solid and they are going to be consequently dark. So, I draw these edges hard that was not a nice idea for me to stop in between and then continue again because that is what happened the intensity of the pencil was not uniform throughout when I was making that line anyways. So, let me draw the center line I am done with that let me work on this arc. So, that at least I am done with this portion of the sectional front view again this is a bigger arc. So, I need to be a little careful what I am drawing it need to make sure I touch both sides possibly I do not. So, maybe I need to reduce my radius little bit or maybe my center is not proper it looks like it is now. So, I will just about leaving a little bit of gap I will come back to that later and do a photoshop touch I draw the rest of the semicircular arc just to get it uniformly ok. And then I draw the rest of the horizontal line maybe using the back side of the drafter because I can see it from here I will go the other way. So, that by the time I reach the arc I go easy on it from here the same thing I go from right then here just a little freehand photoshop touch. So, this part is done now maybe I can increase my speed little bit. So, this vertical line is coming from this part of the top view here. So, I will take a projection I already switch my pencil this horizontal line is getting extended after this. So, maybe I will draw this line of course, I can do this a lot better I should have ideally drawn this entire line to start with, but anyhow nevertheless this is my horizontal line should have little more careful that is ok all right. So, now let me focus on this feature. So, this feature is about 3 mm high from this base line. So, let me extend this projection line level come down. So, twice of that is 6. So, maybe it is here. So, let me draw this part and let me draw this part I should redraw this. Yeah, this is a risk that you take that if you do not draw this entire line 7 once some like this happens. So, let me draw a lighter line and once I am comfortable maybe I will draw or take a line of this. So, maybe looks like I am ok. So, 6 from here 6 high from here rather all right and then a straight horizontal line from here up till the end that I know is going to be throughout and I would not be making an error that I made here. So, I will straight away draw this line better and then this height is 19 twice of that is 38 perhaps I will draw this directly and take a projection from here I already have this we are projected down little using that projection going to make this solid horizontal line. This height is about 6 twice of that is 12. So, perhaps I will mark that I will take this projection down again this would be a solid line. So, I will draw a solid line draw this vertical draw this vertical. So, pretty much done with this I will have line corresponding to this projection. So, let me I already have this projection. So, let me extend this draw a vertical from here am I left with anything yep the red part. So, I have everything pretty much covered this drawing looks among us, but nevertheless. So, pretty much covered over here everything just the red part remains otherwise I think I am in control. So, this distance is about 12 twice of that is 24 I mark that using my stencil scale finally, I draw this line pretty much done. Can I do something about this horizontal line since I have been using this eraser anyhow and I do not want my grader to get the impression that I was not serious enough in my drawing. Maybe I just erase this part and erase it well wipe this part off maybe try to redraw the lines around not a good idea, but this part I will set pretty much this part I will set to be careful this time. Maybe I got the same line all over again nevertheless need for a little bit of photo touch here possibly that is ok now I will not bother myself too much about this. So, except for the hatching part everything else is done maybe I just want to finish this drawing. So, hatching is the tough part and the reason why it is tough is because you need to ensure that the spacing between the hatched lines that is uniform. And if you are doing the hatches they need to be at 45 degrees pretty much and if you have used hatch lines very much essentially if you have many components in your assembly then you will probably need to change the angles, but for now let me retain this angle as 45 or close to it if not 45. So, this has a least count error of I would imagine minus 2 or something. So, this is the only time that I am going to be changing the way I use my drafter maybe about 42 degrees maybe 40 it is about close to 42 degrees. And once I change it then I am going to keep it like this to ensure that the angles of these lines they remain the same. Now, for hatched lines I would rather prefer to use a 2 h pencil instead of an h pencil for 2 reasons number 1 maybe I could hope to get a contrast between the h and the 2 h and maybe of course, it will look better of course, the sectional view will look better. So, perhaps I will start from this region I am going to make sure that the hatch lines do not cross the solid lines this is the most time consuming part, but once done the drawing will look beautiful. So, this is the way things are to be hashed what I will do is to save time and to save roll I will ask my friend Asutosh to stop the camera and what I will do in the meantime I will hatch everything up and then I will ask him to start or roll the camera again. So, that he can see the final picture as I said before this is the tough part it is also time consuming. So, after some grueling effort this is how the sectional front plane would look like if you do this right and if you do this a little artistically it will look beautiful. So, a few things perhaps this arc is a little dim compared to the sectional line. So, maybe what I will do is I will go over this arc again and make it darker. So, probably it looks better now and maybe the last section line once again these are things that in general I am not supposed to be doing, but you know just to leave an artistic signature on the sectional view. Now, if you remember let me first written out my drafter if you remember I hesitated a little bit over here and the reason why I did that was because I should have marked this center line by a sectioning line as opposed to a center line. Because this is the sectional front view imagining that you have cut this object along this line taken away this portion and tilted the object and then you are looking at the object in this direction. So, this part of the surface is sectioned the circular feature is not sectioned this circular feature is not sectioned the rib is not sectioned because the section plane is parallel to the rib and of course, this part will not be sectioned and this part will be sectioned. And this is a single object and that is the reason why I have maintained single 45 degree section lines coming back to this line what I should do now is erase this and replace this by sectioning lines. So, what I did was I went off line and I replaced this line by a sectioning line. Now, you probably would not realize it, but just to tell you the secret I have got 2 small dashes followed by a large dash followed by 2 small dashes pretty much like a hinge line. So, this is a different convention that I use for sectioning plane and to mark the viewing direction I use vertical arrows on both sides draw the arrow heads and then I say a and a. So, I have set section a a over there and here I will just write section a a. So, I have marked these 3 horizontal lines for me to write section a a here I will go off line because I need to keep my head close to these lines to do proper lettering. And after I have written section a a I will come back and show this entire figure to you. So, I went off line wrote section a a did some finishing around this essentially erased a few light lines and my final stroke an example 4 I just draw a horizontal line I think that will be it. I would not be worrying about dimensions in this example though I should, but that is not the important part the important part is to introduce you to sections. Now, let me take this draft away and let me take my sketch and the main object off and have you look at the final sheet.