Hello everyone, today to introduce the drawings Getting Started Knowing the articles here to note that today we take you to the entry is to understand how the drawing is not to teach you how to build it because then if you want to build a drawing basically have to there are some engineering foundation have the means to do so today is to teach you how to be able to understand what drawings drawings defined here is it says here, some people may wonder now use 3D design software Why do I need to do a 2D drawing to drawing so it is used to map the most important communication is a universal language so the world even if you do not have a common language of another country a drawing others to be able to read engineering drawings so it is a "map" it is ultimately to achieve the effect of communication so we are drawing surface is what kind of information do drawings to convey to us that there is a standard extension of this standard by using a more appropriate way to achieve bilateral communication the purpose here in simple terms we will take you to know about how to be able to understand engineering drawings inside information here, we want to know how it does keep looking next to introduce Hello law and projection angle of view is introducing this chapter can be very time you obviously know this piece of machinery for the sense of space is no concept will be very intuitive feeling from the general view so early is a perspective view is not very dependent on the plan to see if it can wait a perspective view from the plane directly think of how long way or the other way around from the perspective view of the various views can imagine it is a good representative of what shape your sense of space depends on a good sense of space, then to learn to use more machinery will we start to look at Taiwan's mainstream angle method is the first trigonometry the first part of this law with the angle of the line represents the projection surface so the first trigonometry we will first see and then see the object in the projection angle method is to first see an object in the projection see it projected out projection views this point of view is not the same you know what you can take a look at our next projection view projection view you can imagine it has an object in a cube inside the cube and then do various angles of projection cube and then start to this time it is necessary to have a way to understand the concept a little space to this pattern here does not matter if you do not have this feeling we can be assisted through a perspective view of the object we know what to say its shape in the end because now we can easily put a perspective view even various angles can be released so you can more clearly aware of this perspective view of the main parts in the end is what we are doing with the first angle method of triangulation in terms of time, then the most commonly used is the three-view three views is a front view, right side view, and this is the view from here, what does it mean literally can intuitively know what we mean front view from the front when it its shape depending on what is the view as seen from above its shape is the same as how most mainstream right side view of the truth of We are before the first trigonometry, right, usually a more isometric view other relatively left, after the next, and so is in a different perspective to look at it here to let people know what you know to the sense of space and projected view after La then we look at just the perspective projection views are understood to generally give a few examples like this to let everyone know about the upper left is a motor that is servo motor servo motor from the front view, top view and a right view like this where you can try the perspective view of the cover up and you see three views of the same reason the other three views you have no way to imagine it is a perspective view of how or cover up these three views look a perspective view do you have to imagine what it was three views so what if the child has done aptitude test you for this one might be a little bit concept is the impression we have is a view of a blank for you to do if you feel you choose this piece is to get started on your behalf is a sense of space this can be a very good way to look through for three-view or sense of space in the end there is no such concept of what these so that we come to know about the three views to feel the feeling back again wait chapters introduce some other views it would be easier to understand, oh then we want to introduce auxiliary view auxiliary view is very clear that we can literally know it is used to assist with generally positive about the projected words are vertical vertical up and down like this because there are some words or parts it is an object may have a tilt angle we imagine it is assumed that after a single bevel single bevel orthographic you go up the side length of it is bound to get you to go short this may understand what this feeling is here for this reason that we have no way know its ramp or inclined surface on the front the size of the real size and shape so that the need for auxiliary view of the auxiliary view is directed perpendicular to the edge of this projection it is a true length of the main view is used to facilitate three way performance is not enough of this part when the object is used to make auxiliary view auxiliary auxiliary views of parts and then we know how to label this size it or we let people know where the original look of its shape is like this here so that we understand what is a sectional view with Hello Next this section line in the drawing is a very classic view because we can handle very large drawing in section views so we have a cross-sectional view of the concept is very easy to see even so the structure of the parts to be when there is a cross-sectional view especially careful if you have some design patent or some of know How in there you do not want to let people know if we should be careful to use a section view because the general is a peer or expert if you look at a cross-sectional view of the design is to know how to do If you have seen the Patent and so some information you might find to say there is a considerable number of cross-sectional view of the same fact, if you look at the field of patents in about Section view plane to know how it is designed to do so although it is very easy to use but it is still possible to accidentally leak your information section view here is very intuitive it is to cut it open later to be on it know the internal structure of some of the parts we like here to indicate what it is a bearing which is a tapered roller bearing we see from the front view of the case is not very clear what the internal structure is only know that it might have some balls ball and not very clear to we do a cross-sectional view of the profile after the original came out to see where it is and it is not tapered it is a roller ball the way so this is the case through cross-sectional view of the inside structure is very well aware of what this is like a gear front view it is also not out to see the internal structure but we cut to a general section view even here it has a hole we can look directly out of being cut off sectional view then usually add hatch hatch is such that we see child it is inclined to this line here have something oblique lines on behalf of this place is a sectional view it is a half-section like us through so that you can know that this is a cross-sectional view it is not simply a front view or the view is being cut over here if you do not know much about it does not matter about the way in here to explain a bit more depth to this side in general is so common direct or cross-sectional sectional sometimes is like this in the section there will be some different angles have turning point turning point in our profile come up depending on the projector like this so it has some places that do not draw a cross section line because this is the place to see the vertical direction so here it did not show it in general there is another approach, called positive view profile view profile is positive in some turning point in its path section line it up so positive we can directly see its length after positive cross sectional view of the finished items you would certainly be much longer we watched it from it is a general section view is projected directly over the positive side section view we have to put it away to give it positive to positive then positive again through here, so it will be longer here. it means to have the entire cross-section over here is even positive projection can come here know that is how the internal structure are all in use here so that we understand how the cross-sectional view of its usage is here to introduce the next La enlarged detail view of a detail enlarged view is very it directly means that the map is like a magnifying glass to enlarge to do the same meaning Why do we use to detail enlarged view of part of it because sometimes it could be a very large number of very small features and so the whole drawing looks like a relatively very small here it is illustrated a belt pulley belt ditch ditch half-section just after the last chapters have talked about a half-section profile view can be learned but the overall proportion of its original side here is the belt groove of view that is too small How to do it can map this place through an enlarged detail enlarge enlarged so while it is not necessary to do this again cut cutting place as long as you want to enlarge on it to show it through this enlarged view of detail is also very good sometimes do not have to do with this place is not very good mark because it is too small can be marked through an enlarged view of detail it even amplification people will look at you in Figure enlarged view of the detail will be relatively less difficult next step is to introduce the broken broken view are generally used in view of the long-shaped objects such as what like iron pipes, H-beam tubes and the like such classes, class iron pipe, the material type, it is a very long cross-sectional dimensions can be all the same view through broken because it represents the size may be very long 2m, 3m 6m etc. even into view above the section size is relatively small so they become broken through the view can make this place a break line break line do mean to say here are all here to the same can be done here to know the total length of it will be omitted as there is such a linear slide in this manner may be used sometimes because the linear rail length is long but the size is a cross-sectional view of the same can be broken through the drawing then it will not scale up beyond the drawing page view, annotation, and so will better appearance can be more clearly seen in the drawing is to let everyone know about what La next to introduce the dimension here is the general drawing will first see the icon view icon is placed in the first place after completing finish, again is dimensioning this time to see how the size is generally more often see is marked between the sides or angles like here round round round φ means that if a 9mm this 4 means that in this view are a total of four holes φ9 like here where we sometimes label will mark its center line like PCD here it means that the hole φ145 centerline size is 145mm and the circle 145 in place here is a 45-degree quartered it means here is such as to represent a block 130 where it is block 130 block 130 so that it is transmitted through motor so you can know what to say about where the size of the motor so when the first plug-in may just met through projection view look at its size can sometimes be more clearly aware of this motor is the motor would say we would want to frame 130 said 130 boxes mean what is here on behalf of the border is 130mm or hole is φ9 φ9 is what is meant here is the hole φ9 when using the screw holes and then a few boxes are much again is its total length here as its overall length is 202.5 motor generally is more concerned about the mandrel is the place we have just learned this way the auxiliary view is viewed from this perspective as well as an enlarged detail from FIG enlarged detail here, it can be see from the auxiliary view see that this is the outer diameter of the mandrel φ22 φ22 can be seen from this that there is a keyway The width of the slot width is much depth is 8 and the number is 32 here can know through the other side so that the corresponding dimensions of the motor can be seen that if there is information corresponding to so design dimensions can be known through these other we want to design the adapter board how to do it or that you want to buy the motor of this size probably see how much you can know the size of an idea to be here to let everyone know about how to see the next drawing dimensions Hello reintroduced the field is a little deeper surface finish symbols just have to know the views and section views before drawing with dimensions above again you may see some symbols here working for example as shown here - have a mean representative said this place is not working on behalf of the other side not working then there will be more representative of the triangle triangles do it here is the surface roughness of finish turning action will be more careful on behalf of the triangle, the less the greater the roughness so see that there are marked TRI representatives here on behalf of what is to be processed so you see this icon cylindrical outer diameter φ50 marked triangle on its behalf to car repair and this section is marked "~" mean that it is not working so here is when the cut material after switching off do not need to do this process on the surface to do original parts using the hole here to do the processing and then do the same process this place but it is the inner diameter of three triangles represent it to fine cars here again give an example here there are three triangles of what a G does this mean that this is the meaning of the milling industry representatives G very often see this article on behalf of pulleys to do to do the grinding surface of the car after completing this course, this is not true here marked this Examples of grinding just do it generally should the two sides to do so is right here is to be a model for your reference here have seen the other corresponding to surface processing in addition to the shape of the symbol "~" is not working outside the other is to do processing here is the more common understanding so basically as long as most of the drawings used here is enough to make people understand what is described in the next Hello datum datum is a very important part because the parts do machining datum If not there will be a deviation of this size variation you may start a chapter for a moment behind this one is more tolerance with no concept of tolerance datum here there is a little complementary concept to see it from the screen assume tablet is a tablet to do with processing see the left view to the right view in the end what difference does see that there are pull-out boxes mean that the triangle represents the datum a datum with datum B What does this mean datum represents the beginning parts after processing the material you need to finish processing A A A datum reprocessed B have to do here with the B datum clamp time we should do with this other dimension extending datum representatives assume to be drilled from the start and then A datum A 10mm up and then back to base level and then further on 25mm A reference plane back to this further on 40mm between representatives of cumulative benefits of a hole and the hole tolerance will be relatively small because the starting point is to do A datum A datum represents the return to zero and then back to zero relative (tired performance tolerance) will be relatively small if not, then do mark directly from well to well up and then continue up 10 15 15 we further on it will have tired from below the surface between the hole and the hole move performance tolerance generally how this hole will have more bias problem here, we look at the process of how the process is only through this way to mark this way because sometimes the right label is not uncommon to do something like laser cutting, then this is no problem If you are in a milling machine will assume the reference plane must be left the way you bore hole is not important assumption here is that you assume that I want to use just 6.2 screws attached and screws are M5 M5 screw 6.2 is good enough maybe you do not need to be used directly as datum mark to the right mark law can be a general tolerance tolerance details will come later do we explain to understand what the concept is, it is a reference datum and then starting from the base to reduce the tolerances accumulated because of the way cumulative tolerance time if there will be more sophisticated dimensions of the problem are all in the assembly, but there is no way to assemble a difference here here to let everyone know what is next to introduce drawing inside would let us have tolerance here tolerance is a concept in the field of engineering drawing is very profound, although it has a standard this standard is not absolute because tolerance is a reference value as the industry would do with the process or processing methods will have different tolerance sometimes is not necessarily the more detailed the better is to look at the process behind the summary here wait time will probably be the way to solve here with you with you here first to see the concept of tolerance has a cylindrical hole in the middle and then assume our hearts with the mandrel to do with the shaft hole assembly is mandrel shown here above are the main spindle 25 is 25 and the bore 25 is here we want to say to the assembly into the like? I would have a problem if the mandrel 25 , the spindle hole 25 is also no way to put the concept of tolerance so that said mandrel must be smaller hole a little bigger a large assembly when assembled together as long as the only way through this concept can know you may often hear hole basis, shaft basis and we do not want to be too complicated shaft is slightly smaller with a concept here is that you can know shafts are generally used to process lathe processing small car it is easy to do on behalf of the shaft small hole put it OK to imagine in drilling drilling sometimes deviation deviation will drill up again slightly larger holes so large axle vehicles completing this concept to become smaller tolerances to know how to mark it here for everyone to see here let me it is a small spindle 0.01 0.02 0.01 small industry terminology will usually say a 1mm inside it will be divided into 100 10 0 is representative of a 1mm 0.01 0.1 is 10 if 50 is 0.5, where a smaller so two small holes 2 so that it is assumed that a large zero which is the lower limit of the aperture is 0 when the shaft the upper limit is -0.01 this can not fit is because it's a smaller tolerances have an assembly can be done if the axis is labeled 0 -0.01 we do not pay special attention to tolerance 0 0 pairs 0 pairs 0 is no way to assemble or that the upper and lower shaft assembly can not become too much tolerance hole is too small so pay special attention to this other place like this 0 +0.1 representative said here that it will be relatively large, but there are actually doing here so I can set aside 0 then it is not too big too big, like 10 big way as this is a key way to do this generally broach it with tolerance is not a problem here as this place is a keyway keyway should be used end mill end mill to give it marked two is OK here, we have to look at what our process is sometimes too small to process your mark not do anything, then we should turn to correct tolerance here if you want to see map in fact, sometimes if there is a way to do this quotation from the tolerances of parts sometimes look through to see tolerance tolerance will be able to know that there is no other details explore here to tell you how to understand it and then look at the shape of Hello tolerance just look at is the size from this view shape tolerance tolerance look is assumed here that the reference axis is the reference axis A A see the two concentric circles which represents the outer diameter of car repair time means that keep the concentricity of the axis perpendicular to the plane of the 2 to 2 here is the concept of what it means to let everyone look at another illustration here is a bit like the integration of just the first few chapters and then integrate it all together like a form tolerances as well as surface finish and dimensional tolerances and dimensions and so symbolic reference plane we need to do grinding grinding finish on the surface and then the amount can be integrated after watching it like there's hope its flatness flatness of the surface with datum a has two representatives a datum can start doing machining End table flatness is measured when the two labels means that it is like this as well as after completion of milling where plane a and plane from the two other dimensions do two milling marked with the reference plane B C plane Representative this is like the keyway groove will generally have to do with the positioning of vertical and horizontal perpendicularity look to be perpendicular to the vertical plane B B side is out of the vertical in this way is to do with the positioning of the side structure substantially on the other dimensions do to avoid accumulation of quasi-tolerance do mark from this place there is no problem here long trench will be bigger because it is the use of vertical sides so long trench may be slightly larger may be dimensioned large 10 20 Article no problem here for everyone to look at the details of the most important tolerance can be seen from the drawing out and tolerance is doing the design can be seen from the success of the design tolerances So if you encounter out there is no way to do the assembly on behalf of tolerance here is where it needs to be done to explore correction here to let everyone know about Hello to sum up the last entry papers drawing awareness through projection view, front view, auxiliary views, and so again plus size, shape, dimensional tolerances, datum look at the original meaning of these icon represents what is after so you can understand more clearly aware of this chart you can also say that it is drawing a map it can be What does it mean to convey is that we see it to know what it means to communicate it to achieve the purpose so be well aware that it is ultimately to communicate, so if you find a picture you are able to understand the inside of the respective symbols but do not knows what he wants to express on behalf of the drawings may need to do this correction drawings although it is a standard but in the end still have to keep doing some modifications to make it possible to convey the true purpose of the communication just mention here part tolerances and tolerances the more detailed the better not set a small two even smaller tolerances 0.01 like this is not necessarily true for example like to do a good welding welding tolerance usually would not set such a fine tolerance sometimes two people are given this fine there is no way to do it because basically welding yaw likely to 1mm, 0.5mm or bending sheet metal in time there is no way to do this a few fine may also need to 1,2mm here is through the process and sometimes you do not know there is no relationship can be fed back through some of the most direct suppliers of fact, if we can do personally is this the best way though you may not have the same experience, but experience is accumulated through their own production or others tell you this is the experience accumulated through If a way you unfinished drawing or looking at this picture when I watched do not know how to do it on behalf of the icon in question if the amendment but to do it to understand it has not done it on behalf of the basic roughly eight are other small details will not be a problem to do it today, is amended to entry in this way, we meet at the drawing to see how it ends up it to achieve the purpose of communication to convey it to this teaching today So far the side we look forward to it next time teaching Bye ~ Bye ~
