 .For the 1st of February and the 2nd of February, 1st of February and 2nd of February. And so this is for you to get familiarized with the software, one of my students will be taking the workshop and after you get familiarized, the next AutoCAD session will have you work on a little problem. So, that would be on the 8th of February and the 9th of February. So, this is the tentative schedule, badges B 4, B 5, B 6, B 1, B 2 and B 3, they will be doing their labs as well as workshops on Friday in between 9 and 1, people like and the rest of the 6 badges, they will be working on Saturday. So, I believe you are going to be having your NCC or NSS or whatever CPA on Saturday mornings yeah ok. So, I am assuming that you are free in the upnoons of Saturday ok. So, it is from 1 30 p m, 1 30 p m till 5 15 p m. So, if you scroll up a little bit on my web page, we have a manual for you, we have a primer ok. So, you can download it, take a print out, make copies, borrow, steal if you want to ok. I believe that in the labs, we also have internet connection. So, if you do not want to take a print out of this, you can access it through the net, whatever. I would suggest that you take a print out of this and have a copy of this with you while you are working with the problems in order to get. So, today we will see another example in orthographic views third angle and this is one, this is the solution to one of your problems in lab 3. Things will get a little complicated from now on. So, some of you are not able to access the power point presentations through the web, is it, is it, is it the case. So, I believe in computer center you will have either the Linux based labs or the windows based labs. So, I have a feeling that you would be able to access them through the windows lands ok. So, try that, try that out. Linux I am not really sure of they would support PPSX ok. Let us get started, you know when I was on the other side of the table when I was sitting amongst one of you long time ago, not so long ago. We used to see this ad, do you know who this is ok, one more time ok. Set of curves, set of lines, ellipses tells very well with what we are discussing in class and there was a statement with this ad. The greatness of this man was his simplicity ok. He taught us, he taught the entire world a lot of things and I would want to say a lot of things about him, but I would rather focus on the example, but one of the things that he taught about or he taught to us was to go bottom up in anything that you are doing. Do not go top down, but go bottom up that is the logical way of approaching any problem and T a is all about going bottom up alright. So, example 2 this is going to be a little complex. So, we are going to be drawing the orthographic views third angle of this solid. So, this happens to be one of the problems in lab 3. So, I will project this picture for a while, you have your notebooks and pens in front of you. How about taking 5 minutes and trying to sketch this without making much noise. 5 minutes is too less a time for your sketch, but try it out. So, let me hear only the scratch of your pen on your notebook nothing else think and analyze. So, of course this side of the solid is the front view. So, for those who have already done lab 2 yesterday and today is it a little more difficult or quite straight forward. So, we have 2 cylindrical features here. So, if you are having a hard time understanding or imagining the solid I would suggest that you break the solid down into different features. So, you would have 2 cylindrical features here, 1 rib at the back, 1 tapered rib on the left, 2 supporting ribs behind a plane with a so to speak electrical void and these are circular through holes. So, break the solid down into different parts that will help you imagine the solid little better. Let us start drawing, focus on the bottom right box of your sheet fill out the details. Can I go back a little these yeah well the pictorial view this is not. So, very clear, but your assumption is valid. So, you have to assume that they go all the way back they stay horizontal and they go all the way back. So, first fill out the details in the bottom right box of your sheet use the convention for third angle projection. So, for this one I am using scale 1 is to 1.5, I am using scale 1 is to 1.5 alright was the first thing that we need to do hinge lines, but before that identify 3 critical dimensions. So, if you assume this plane to be the reference plane this dimension over here corresponds to the dimension here the height of the rib this one here takes you back from the reference plane and this would correspond to the length of these cylindrical features alright. So, this drawing will draw this using reference plane in mind let us see how reference plane draw the hinge line that differentiates between the front view and the top view and then what bounding box what is the length of this 60 what these bounding boxes corresponding to these cylindrical features that is what you would see. So, you would see this plane and then you would see these cylindrical features. So, it is actually 60, but the scale is 1 is to 1.5. So, I am reducing the dimensions I am reducing all dimensions by 2 2 3 I am making a mistake I am making a mistake good. So, long as you are realizing or so long as you realize that you have to show 2 dimensions I am happy for now I am showing the scale dimensions for you to understand what is this height 90 times 2 0 3 take the projections up the first thing that you would want to draw in the top view is the reference plane this plane. So, you would see that this plane is a line or is represented by a line in top view what is this dimension what would this dimension correspond to how much 1 of you raise your hand and 24 scaled dimension 2 3rd now. So, from this reference plane you are now measuring the feature at the back what is this dimension I am depicting you the scaled I am depicting the scale dimensions. So, this is for you to realize the scaling all right. So, the top view will be bounded in this box take this projection upwards and draw the bounding box for the cylindrical feature what is this dimension do the same for the other cylindrical feature as well. So, of course, a cylinder is symmetric about this axis you show the axis a x e s of the 2 cylinders using dash long dash short dash long dash short dash or dash dot the convention that we have been using and then start relating the top view to the side view using projections 45 degree line go down relate the side view to the front view as well that is your reference plane in the side view what would this projection correspond to what would this projection correspond to the cylindrical feature in the side view. So, this is the box that bounds the cylindrical feature yeah it is symmetric about the axis show the axis of the feature. So, once you have the groundwork done once you have the groundwork done start drawing solid lines start with the base first step then what the vertical on the left vertical on the right. So, this line corresponds to what this one projected on the vertical plane good this edge corresponds to what this one good that is the rib projected on the vertical plane what is the width of this right let us proceed this is the circular void through this cylindrical feature the center is the intersection of two dash dotted lines same thing on the right would you see this edge should I be drawing the full circle or should I be drawing three fourth circle for this three fourth how about the circle on the right three fourth now be a little careful here be a little careful here what do I do next I need to worry about this dimension this dimension is 8 I draw a little fillet from both circles and I join the two fillets by a straight line ok am I done still a long way to go ok all right sell down what is next dimension the inner void what is this called what is this called pi all right pi what what is this part of the dimensioning called leader angled at 45 degrees to the horizontal and then followed by a horizontal line this is R 12 what is this height see this gray line here what is this height I am drawing this void now settle down settle down what is the site look at the first center look at the second center what is this what is this distance I am helping you with one of the solutions ok come on what is this distance 14 point how I located the two centers properly one here one here yes or no draw two semi circles join them by two straight lines and you have you have what you have a void which looks almost like an ellipse but it is not an ellipse it is a slot am I done what am I left with one at a time somebody raise your hand the dashed lines of the backward these guys how about this guy still long way to go we will come back to the front view little later let us start the top view two cylinders now now now hold on hold on the extreme edges along the intermediate edges are shot these two edges along these two edges are shot why is that why is that because of this feature now so it becomes easier for you to have a reference line or reference plane and then draw things with respect to that plane take the projection of these circular voids upwards to top view and use dashed lines to show this void in the top view and likewise for the void on the right okay so this is an example that will demonstrate that it is there are chances that you are going to be missing out quite a few lines not just one not just two but quite a few yeah well what edge this circle this one will it be visible we will come to that so for now are you with me are you with me for now okay who is not with me it will be a curve part all right but imagine this to be a cylinder okay what do you see rectangle okay so imagine only this part what do you see we will come to that we will come to that yeah no but we will come to that we will come to that so if I am making a mistake feel free to correct me but catch up with me okay you are with me now good stay with me all right would you see this line would you see this line what would this edge correspond to what would this edge correspond to this guy here would you see this line yeah no this would correspond to this over here I believe is it okay now comes the important part so this is a ribbon okay and the rib is such that a part of rib is tangent to this circular feature here and here okay how do you show that a line okay it is kind of extended up till the axes of the two cylindrical features okay and to show that it is tangent to both the features we use a little convention we show a little arc on both sides okay once again this rib is tangent to both circular features okay so correspondingly the line is going to be extending towards or up till the axes of the two cylindrical features and to depict or to emphasize that this rib is tangent we use two circular arcs at the two ends okay something new what is this dimension what is this dimension what am I doing now I am taking the projections from here to represent this void in the top view okay you will see two hidden lines of course where would they be where would they be where would they be one would be here and the other one would possibly be here once again watch carefully things are getting a little complex now I am taking the projection from here for this rib what would I see in the top view a hidden line up to where up to where up till the reference plane up till this plane up till this line here okay coming to the side view cylindrical feature is easy cylindrical void is also easy yeah which one yeah this is like a tapered rib where you yeah so this is like a tapered rib okay so it is glued to the reference plane okay so here the thickness of this rib is zero and here the thickness is 24 is it scaled or unscaled unscaled so two third of that is 16 okay so if this is your reference plane at the bottom the rib is going to start from here and at the top is going to come here okay right and since the rib is hidden behind the circular feature or cylindrical feature in the top view it will be shown using hidden lines hold on are you all with me who is not with me you are not with me you have it out inclined so this is this is an imagination issue okay folks folks people like so you will start imagining things better once we start dealing with isometric views for now assume that this is like a tapered rib okay alright so coming to the side view cylindrical feature cylindrical void this is what reference plane okay this edge this is what is this edge okay straight forward steps two steps straight forward this dimension what is that now so how are we doing this we are sketching the front view in part we are sketching the top view in part we are sketching the side view in part we are going back to the front view okay and we are relating different features in all three views through projection lines horizontal vertical right so corresponding to this step here there would be dash line in dash view fill in the blanks one hidden line the second hidden line and the third hidden line and the fourth hidden line there is no point because that is occult or that is behind the solid behind the solid line one at a time I will come back to you with this part which strip you know I am so very glad that you are discussing amongst yourselves can I have all ears please all ears here please all eyes here please thank you I am so very glad that you are discussing this problem if you are with your neighbors which is which is a very nice thing possibly this is not the right venue for that okay feel free to go back to your hostel rooms and discuss this as much as you want one lesson in in fact two lessons well one lesson in communication skills 101 lesson number one if you want to be a good speaker you have to learn to be a good listener okay if you want to be a good speaker you have to learn to be a good listener and if you want to be a good leader you have to learn to be a good which one this one behind what strip this one so as I said I mean this picture is a little ambiguous so assuming that that would go throughout okay we are working with these solutions assuming that okay you will learn later how isometric views can be ambiguous this is an example so are you with me now three in lines listeners what does this stand for what does this stand for calm down calm down yeah yeah up to this band huh well so in fact this is what I explained to Shekri I use I am assuming that these steps are going throughout okay behind the solid okay so that they are not stopping anywhere I am assuming that I do not have the information but I am assuming that they might as well have stopped over here they might have stopped over here they may have stopped over here okay but in any case I would not have known about that because that corresponding feature is hidden behind the reference claim okay so there is a little bit of ambiguity in the picture but I am assuming that they are going throughout well the picture will be the same or similar yeah so as I said I have to give you additional information here which I have not but I have to give you additional information okay for example a phrase like extended throughout okay are you all with me okay so going further this projection line corresponds to so this this would actually help you depict this void in this idea hidden or solid lines should I be showing this axis okay in lines in lines I am jumping I did a bit of side view and then I am going to the top view and I am drawing the back portion of this now look at these lines look at these lines I did not start from here I did not start from here rather I started from here okay if I take a projection of this that would match with this vertical line likewise if I take a projection of this that would match with this vertical line that would be a solid rectangle am I done still some work left what is your first impression about this drawing complex simple very simple complex difficult easy very easy unclear in the pictorial view you mean in the isometric view the one the right top right yeah yeah so I agree with you I agree with you I should have given you more information but it is only these parts in the picture which is not clear which are not clear they are more which ones which ones these guys these guys these voids well so if I so hold on hold on so there is a term that we use to depict the depth of the void okay deep so when I say 5 let us say 10 and then 10 deep that means I am referring to a pothole with diameter 10 and depth as 10 or 20 if I do not specify that depth you assume that is a true void okay about 10 or so more minutes and then we are done it is very likely that you are going to be missing this line in the side view okay there are so many lines thank you there are so many lines that you are drawing that is very likely that you are going to be missing this line in the side view okay that corresponds to this edge here okay all the lines that I am showing from now on are pretty much in red these are the lines that you are going to be missing okay top view profile view this is the line that you might be missing what would this correspond to what would this correspond to this line corresponds to the intersection between the cylindrical feature and the red what would this line correspond to this guy here okay you might forget you might forget to represent this central central so to speak electrical void in the top view okay so the center lines here you already represented this what does this line correspond to on the right side what would this correspond to it is this plane it is this plane right in the arches view have you done no so when you are drawing these orthographic views you need to be very careful okay and one way one way to practice or exercise care is to ensure that each and every feature in each and every drawing is related by the corresponding projection line or the construction line this arc no but this arc is okay this arc is used conventionally to show tangency between two features okay so it is just to show that this rib here is tangent to the two cylindrical features on the left and on the right these guys huh what are they correspond to the two centers don't miss out any hold on so don't miss out any sort of line don't miss out any hidden line don't miss out the center lines don't miss out the lines of symmetry okay be very careful yeah you know I believe in learning by making mistakes okay and I am not at all shy to admit that I make mistakes I made a mistake so notice notice that I am using a different can I notice that I am using a different dimensioning scheme I am not using I am not using aligned dimensioning but I am using centerline dimension differences are subtle differences are subtle the number or the dimension is represented within the arrow okay almost at the center of the arrow okay and whether you are using horizontal arrows or vertical arrows the numbers they remain they remain what aligned to the horizontal they don't get rotated as it is in case of aligned dimensioning okay again as I said as I said there are mistakes one of the foremost or one very glaring mistake is the fact that I have used scale I used scale dimensions I have not used two dimensions so when you are making this drawing in your lab sessions make sure that you don't make the same mistake as I did