Draw the third view and the points on each view. In the first picture you have what the exercise has given us and in the second what I have drawn. I have turned the page so that the first view is the one on the left, the horizontal one is the one on the right. Is that OK? Should I use the one at the right as a lateral view?




When drawing orthographic projections, it is convention to draw the "front" view in the middle of all the other views;

The "top" view is drawn above the front view,

the "left side" view is drawn to the left of the front view,

the "bottom" view is drawn below the front view, and

the "right side" view is drawn to the right of the front view.

If a "back side" view is desired, it is drawn either left of the "left side" view or right of the "right side" view.

Diagonal areas of the page are used for isometric projections or renderings of the object in question.

Take the example below.

Example Projections

While all the views described above can be put onto a drawing to represent the object on each side. With the use of both object lines and hidden lines, the whole object can be defined using exactly three of the views described above: one drawing for each dimension of space. Typically, the front and top view are drawn in conjunction with either the left or right side view.

Addressing your problem specifically: The problem you have been given seems to be a bit ambiguous as to which view is considered the front view and which view is considered the side view for this object. Based on your drawing, it seems you chose the left hand drawing to be the front view, and the right hand drawing to be the right side view. If you have been given no other instructions, this choice should have been fine; it was left for you to decide. However, those two drawings seem to be arranged on the page incorrectly. The left hand drawing seems to be the right side view of the right hand drawing but was placed on the left hand side for some reason (use the subtracted cylinder and different height "shelves" to verify this observation for yourself.) Because of this, I think the problem you have been given is poorly designed.

If we work off the assumption that the left hand drawing is the front view, then the 3rd view you have drawn should be the top view. However, based on the way you have drawn your object lines and hidden lines, it looks to me like you drew a bottom view. (You are trying to communicate all the geometry above the base with hidden lines.) If you did want to draw a bottom view, that view should be on the opposite side of the front view. Otherwise, you should redraw that top view, keeping in mind what object lines are visible, and which object lines are hidden.

Edit: joojaa has enlightened me to the existence of the ISO 1st angle projection. OP, you seem to be drawing your views fine so long as you intended to use ISO 1st angle projection.

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    $\begingroup$ This depends strongly on where you are in the world and what you are drawing. Since front is a arbitrary decission it can be drawn pretty much anyway one wants. Note that rotation direction is different in US and rest of the world. $\endgroup$ – joojaa Dec 16 '16 at 5:39
  • $\begingroup$ Different parts of the world use different rules as do different industries. For example europeans rotate the drawings differently from engineers in USA and house designers use the top view as their main projection. So there is considerable variation in drawings across the globe. Even here the OP uses different convention from you, but hasent marked it in the image. $\endgroup$ – joojaa Dec 16 '16 at 5:56
  • $\begingroup$ Could you please elaborate? It is true that the "front" is technically an arbitrary choice, but, especially for homework problems like this, the problem should make it clear what the front view should be (this problem doesn't specify this detail). The view arrangement is also universal convention. Indeed, orthographic projections have these very well defined set of conventions so that the drawings can be universally understood by people with a wide variety of design and engineering backgrounds and so that the drawings can represent essentially any part or structure using the same "jargon". $\endgroup$ – Unique Worldline Dec 16 '16 at 5:56
  • $\begingroup$ Ok now the system has messed up our comment order. How nice :) $\endgroup$ – joojaa Dec 16 '16 at 6:05
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    $\begingroup$ Yes, but see there is 2 conventions used worldwide see this image so naturally you get into a situation where you think the other is wrong if your not aware of this, fact. So naturally the rotation in a a different production rule is incomprehensible for the person using the other rule. UNLESS the rule is marked in the drawing as it should! So simply we do not know if first-angle projection is correct or if the third-angle projection is the right thing. OP does not tell. $\endgroup$ – joojaa Dec 16 '16 at 6:34

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