Design, Communication and Graphics written exam

jamo2oo9

Noticed there isn't a topic for us technical lads so here it is. Discuss whatever problem you may have in the written exam.

I do have a problem myself. For 2012, section C, question 2 on Structural Forms, I can't figure out how to get the parabola in both plan and elevation. I have the two curves on both sides and the sloping line at the top. My teacher said I have to rotate the parabola to the side. I can get that but I don't know where to go from there onwards.

Any help is appreciated!

Jamie

Leaving Cert Student

Nice idea for thread, hope project went well for ya! Buzzin for mock next week, bit of work to do beforehand though!

jamo2oo9 wrote: »

Noticed there isn't a topic for us technical lads so here it is. Discuss whatever problem you may have in the written exam.

I do have a problem myself. For 2012, section C, question 2 on Structural Forms, I can't figure out how to get the parabola in both plan and elevation. I have the two curves on both sides and the sloping line at the top. My teacher said I have to rotate the parabola to the side. I can get that but I don't know where to go from there onwards.

Any help is appreciated!

Jamie

As for this, we aren't doing structural forms in part c but i'd have a look at the marking schemes sample answer on examinations or t4.ie if I were you

jamo2oo9

Leaving Cert Student wrote: »

Nice idea for thread, hope project went well for ya! Buzzin for mock next week, bit of work to do beforehand though!




As for this, we aren't doing structural forms in part c but i'd have a look at the marking schemes sample answer on examinations or t4.ie if I were you

I've checked the marking scheme for it but it doesn't have instructions on how they got the parabola. They have a diagram or solution but I can't figure how it's done really.

jimbo28

Its not the case in this instance to have to rotate the object, or in other words project and end view to see it from the side. the shape you require is a hyperbola and can be obtained using cross sections.






the plan can be determined taking a cross section at the apex of the curve in elevation. the plan will appear as a straight line.Where this line intersects the base circle diameter will give you the bottom points of the curve.use further cross sections to determine the remaining points.refer to
http://t4.ie/dcg_applied_graphics.html and go to the structural forms tab.Within this tab is containd a powerpoint presentation on this topic.If you do not have powerpoint, you can download a free powerpoint viewer from microsoft. just google it!

Leaving Cert Student

In perspective, how do I get the VP's? Vanishing points that is. I have all else set up

jamo2oo9

jimbo28 wrote: »

Its not the case in this instance to have to rotate the object, or in other words project and end view to see it from the side. the shape you require is a hyperbola and can be obtained using cross sections.






the plan can be determined taking a cross section at the apex of the curve in elevation. the plan will appear as a straight line.Where this line intersects the base circle diameter will give you the bottom points of the curve.use further cross sections to determine the remaining points.refer to
http://t4.ie/dcg_applied_graphics.html and go to the structural forms tab.Within this tab is containd a powerpoint presentation on this topic.If you do not have powerpoint, you can download a free powerpoint viewer from microsoft. just google it!

Okay I think I have it now. I had to measure 60mm up, line it across until it hits the throat. Brought that point down to plan where I swung an arc until it reached the centre line. Split the line into three segments and then found the points on the parabola curve.

Cheers!

jimbo28

Leaving Cert Student wrote: »

In perspective, how do I get the VP's? Vanishing points that is. I have all else set up

For VPL go paralell with the line AD from the spectator, where this line hits the picture plane, project it down perpendicular to the picture plan (pp) to a point where it intersects the Horizon Line ( HL), this will give you the point. Do the same routine from DB for VPR.

jimbo28

http://www.youtube.com/watch?v=eieTeYlHhww


A decent video on auxillary vanishing points.Pay heed to the 2 angles at the start of the video!

Leaving Cert Student

Cheers lads! Great help... raging at myself for not remembering that one... What 's you guys doing for section c? myself im doin geological geometry and structural planes! handy q's!

kevinw123

lads, any of ye have marking schemes from the pre's? going over questions from it and can't get past one question?

Leaving Cert Student

Anyone post their mock paper up here?