 Hello friends, myself, S.M. Mutt, Einstein professor, Walsh and Instructor of Technology, Sholafur. Today, I am going to explain the orthopedic projections in engineering drawing. In orthopedic projection, next step is sectional view, I am explaining. The learning outcome for this session is student will able to draw the orthopedic projections of the sectional view of the simple object. So, basically, I am recalling that in the last lecture, in the last video, I am going to explain the simple three-dimensional view placed in front of you and we have to draw the front view, top view, side view, that is the orthopedic projections, that is from the three-dimensional view, we have to draw the front view, top view and side view. Basically, why the orthopedic drawing is to be required? Because sometimes, the part is not clearly known for that particular person. Nowadays, we have to go for the next step, that is the sectional view for the subject. So, here to draw of this object, that is the sectional front view in the direction of x and the top view. So, first of all, you have to take the maximum measurements of this one. The total length is 65, even you have to go further in the direction of x, maximum length is 65 and height is 40 plus 10, 40 plus 10. So, you make a block of 65 into 50 and height is to be 50. So, in that square block, you have to draw all the related view of that object, that is the front view. So, today, I have to know the sectional front view, before going to the sectional front view. First of all, I am explaining, I want to draw the regular front view of that object. This is the maximum size. So, we have to start with this point. When you have to see in this direction, this view is parallel to you, which is I am hatching, that is 65 by 40. So, it is start with this one at the point, this 65 length and height is 40. Then, the total width is given as 15 mm, 15 and this depth, this total depth, this width is given as a 15 mm. So, this length is 15 mm, take a 15 mm length, draw this vertical and horizontal, you get the first object of this sectional view. Then, you know this one. Then, this inclined portion is to be there, but when you have to go for the inclined portion, this width, the total height is to be given as a 10 mm here. So, extend. Even it is a inclined one, square one, sorry, what is called rectangle one, but when it is inclined to you, you get as a rectangle. So, extend this line. So, this portion is now over. Now, you go for a supporting rib is there, that rib is started from 25 mm from this edge. So, from this edge it is 25 mm, starting point is 25 mm, that is exactly at that point and it ends on the left hand side, where 40 mm from this edge. So, 40 mm from this edge, it is somewhere here. Now, when you to draw this portion, this rib is there. It is very called parallel to you. So, this portion you have to draw it. Now, you go for this, what you call guideway. Two guideways are to be there. Guideways for this supporting rib is to be there. Guideway, it comes from first end, first surface to the last surface. What is the height? It is given as 8 mm from the base. So, from the base it is 8 mm calculated and it starts from here to end, starts to end and when you to see from this portion, this edge and this edge, this edge is hidden one, which is invisible. So, that is why I have to draw as a dotted one, that you have to know in the last lecture, last video. So, it is a front view. Now, you have to go for a section of this one, sectional front view. Why the section is to be required? Basically, section when you have to show, before going to that, when you draw the three-dimensional view to the two-dimensional, that is, orthopedic drawing, some parts are there, which is hidden one. The hidden surface, hidden edge, hidden parts, which is not to be seen in this portion, which is hidden one and when you to go for the front view, top view, sorry, top view and the side view, these portions are invisible one. So, for that portion, imaginary some part you have to remove it or take a section for that, you have to cutting, cut that particular portion and which parts which are to be hidden one, they are come to the surfaces. They are come to the surfaces and you have to see that whole. So, imaginary that hidden parts are there, hidden surfaces are there, that is to be shown because these complicated parts, hidden parts, they are not clearly shown in the orthopedic drawing, in the isometric drawing. So, to show that, to know the above object for the observer, you have to take a section for that. Now, where you have to take a section for this object? It is given that this line is to be here. It going to AA, this is a section. So, half part you have to cut it, this half part where you have to take it. So, when the half part is to be taken one, the hidden portion it comes to here. Now, in this portion, which parts come to here? This surface come to here, which surface? This surface, this cut portion is to be there. So, this surface and the edge is to be given as it is. So, it is seen as a continuous line now. Instead of dotted line, it is a continuous line. Secondly, when you to take a section of this one, this surface is to be there and one more thing is to be there. When I to draw the section of this one, the rib is not shown because it is a supporting, it is not part of that object, it is a supporting rib. So, that this surface is to be seen as it is. So, draw the section for that and this surface is not spent. I will show you here. So, draw the sections of this one. These lines are to be near about 45 degree and they are parallel to each other. So, this section shows that the hidden surfaces come to here. That is the cutting part is to be there. Cut portion is to be there and that cut portion you have to seen by a section line or a hatch line and this surface is not there. So, it is a section for this one. So, when you know this one, then you have to go for the top view of this one. When you to go for the top view of this one, what is the, this length is to be fixed and what is this length? It is given as a 40 mm, take a 40 mm distance, make a block of this one of maximum dimensions 40 by 65 and this is the center line. Now, when you to see from the top view, there are three inclined surfaces. It is parallel to 20 mm, 20 by what you call this 40 mm is to be there and this width is to be, this is 20. So, remaining portion is 12.5 and 12.5. The total is 45 mm, this is a 40, 10, 10, so it is a 65 mm, draw this block of maximum portion. Now, the thickness is given as 15 mm, draw this one and the internal this one, this portion which is parallel to it is 20 mm. From the center line 10 mm right and left, 10 mm. So, this is the 20 mm center block and remain this inclined portion you have to extend it. So, this part is to be over, now this rim, actually this surface is what you call 10 mm below that when I to see from the top view, this edge is parallel to this one and this width is given as 10 mm. So, right and left 5 mm this rim, so from the 5 mm and from the 5 mm and it ends up to here. So, this portion this is to be over, this is parallel to it, this is parallel which is inclined it is to be then this hidden portion, the guide ways two lines are there, this A and B, they are from start to end where the distance is given as the top most that is given as a 40, 20 and 20, 10 mm and 10 mm and remaining is to be from this end 8 mm and 8 mm. So, the smaller one is 10, this is dotted, this is from A to end, but it is to be hidden one and remaining this one is a 20 mm, 10 mm and 10 mm which is hidden of this here. So, this is the front view and this is the top view, this is sectional front view. So, section is taken to be here from this end, this is a section line A A up to here that portion. So, this portion is to be given then cut portion, remember that the rib or a supporting rib, this rib is not cut portion because it is a support it is not part of that object. So, that is why when I go for the section of this one that part is not cut it is not shown in that drawing. So, now we have to go for the dimensions, this length is given here that is 65 mm and the height is 40 plus 50, 10. Then you have to go for the top view, this width is given as 55 mm, this gap, the thickness here it is given as 15 mm. So, that is why we have to take a section of this one, when you have to take a section of this one some irregular surfaces are there, complicated surfaces which are hidden one and they are not clearly seen in the regular orthopedic drawing at that time you have to go for a sectional orthopedic drawing. Now, one thing when you know the last video, when you know this video, whether this line is to be shown in the section view, I am explaining the sectional view in the previous video I am explaining regarding the regular orthopedic view, think over that yes, when I have to cut this portion this surface is not seen, which one this surface this edge is not seen and it is a regular one portion is to be there, this is the regular one portion is to be there. So, this is all about the sectional, simple view of the orthopedic drawing. So, the basic thing is when you have to go for the sections of this one, some irregular surface are there, some complicated objects are there, surface are there, edges are to be there, they are not seen in the regular orthopedic drawing. So, that is why you have to imaginary cut that object that you have to show that line that is a section of this one, section a a and that part is imaginary removed and then we have to proceed. So, for this one for this references I am taking engineering graphics one, Professor Hemel Labade by vision publications book reference. Thank you.