Tech. Drawing analysis

OTliddy

I thought that was quite tricky. Heres what I did:
Q1:Got everythibg apart from (c), which i half did.
Q3:Got this done, exept for detirmining the anlge between the vertical and horizontal planes on the new plane. I thought it was always 90`?
Q4:A predictable question. I got very mixed up towards the end and didnt know what went where, but i got most of the turning/penetration points.
Q7: A bit af a disaster. Normally my most reliably question. Ended up drawing completly random lines for part (c). Did anyone get the pyramid for part(a) going though the line TH in the plan?

Q1: Got everything right I think. I just looked at (c) and it just clicked! The best question I did by far.

Q3: I thought I did that very well, but I got a tiny cone with a HUGE height, so I'm not sure if it's right. Did anyone else get this?

Q4: Did this very well too. May have put some dotted lines in that should have been full, but besides that I nailed it!

Q5: I thought I did this really well, but when I got home I realised that I made two stupid mistakes, and I'm not going to embarass myself by saying what they were. Because of this, I say it was my worst question.



Sorry to hear about Q7 OTliddy. I just looked at it, and went back to the other questions. It seemed really hard.


Overall, I think I got a A2/B1. I got the exam done an hour early, and left the school feeling really confident.

The Failed God

Yuck Horrible paper, did 1) Got it all out i think.. 2) Took me a while cause i didnt see the obvious tangent so i did a locus which worked so i presume il get the marks.. 3)Dirty question, couldnt do part b so i hard to sketch part c.. 6) Grand question, messed up par b but i prob got most marks.. PLEASE GIVE Me AN EASY PAPER 2!!!

*Angel*

Deleted User wrote:

Q3: I thought I did that very well, but I got a tiny cone with a HUGE height, so I'm not sure if it's right. Did anyone else get this?

That's not what I got...

I started off with Q3 very straightforward I thought (20mins), Q6 was another short Q. Then I did Q7, parts (a) and (b) were straightforward enough, (c) was a little confusing, it took a while but I think I got it in the end. Then Q4 was grand.

Overall I think it was an ok of a paper, I've heard that Q1 (even part c) was the easiest, maybe I should have done it :rolleyes: .

StupidLikeAFox

:(:(:(:(:(

Got the interpenetration question completely right, A1 for sure. Got (a) and (b) of question 1 right. the rest was just

*Angel*

OTliddy wrote:

Q3:Got this done, exept for detirmining the anlge between the vertical and horizontal planes on the new plane. I thought it was always 90`?

It would only be worth a few marks anyway.

OTliddy wrote:

Q7: A bit af a disaster. Normally my most reliably question. Ended up drawing completly random lines for part (c). Did anyone get the pyramid for part(a) going though the line TH in the plan?

Yeah.

jacksie

Q1 - All apart from (c)

Q3 - (a)no bother
(b)Got a very high cone.. think it was right though
(c)Didnt get angle

Q4 - Got most of it done

Q5 - Easy!

jacksie

jacksie wrote:

(b)Got a very high cone.. think it was right though

I knew it! A lot of my friends got that too!!!

*Angel*

If the cone was high it would also be wide, cos if you think that it had to be tangental to the sphere at a point 33mm above the hp then the side of the cone wouldn't have a very steep slope.

You do realise that finding the true angle between the vt and ht is a common enough question in hyperbolic parabloids too, just to warn you.

*Angel*

*Angel* wrote:

If the cone was high it would also be wide, cos if you think that it had to be tangental to the sphere at a point 33mm above the hp then the side of the cone wouldn't have a very steep slope.

You do realise that finding the true angle between the vt and ht is a common enough question in hyperbolic parabloids too, just to warn you.

Not necessiarily. When you draw the horizontal line 33mm above the ground, and then bring it down to plan, you will see that the the point of contact is very close to the edge of the sphere. We know that cone is a tangent to the other cone in the plan (as they touch the ground), so if you get the locus, you will see that it is a very small circle that is a tangent to the cone in plan and in which the point of contact is very close to the edge of the circle.When we find the locaton of the point of contact between the new cone and the sphere in elevation, you will see that it is very close to the edge of the cone (about 1mm in). So therefore the line would be VERY obtuse, as the sides of the cone would have to be inside this point of contact for it to make sense, so therefore it makes cery steep sides for the cone.

Tbh, I just read that and I haven't a clue what I'm on about! It's very hard to describe without a diagram.

*Angel*

Deleted User wrote:

Not necessiarily. When you draw the horizontal line 33mm above the ground, and then bring it down to plan, you will see that the the point of contact is very close to the edge of the sphere. We know that cone is a tangent to the other cone in the plan (as they touch the ground), so if you get the locus, you will see that it is a very small circle that is a tangent to the cone in plan and in which the point of contact is very close to the edge of the circle.When we find the locaton of the point of contact between the new cone and the sphere in elevation, you will see that it is very close to the edge of the cone (about 1mm in). So therefore the line would be VERY obtuse, as the sides of the cone would have to be inside this point of contact for it to make sense, so therefore it makes cery steep sides for the cone.

I disagree with your thin cone and you're confusing. However let it be, sure it doesn't matter now anyway (not really). TD shouldn't be explained in words anyhoo.

*Angel*

*Angel* wrote:

I disagree with your thin cone and you're confusing. However let it be, sure it doesn't matter now anyway (not really). TD shouldn't be explained in words anyhoo.

Yeah i confused myself too!

Well if it is wrong, then it seems that a lot of people did it that way, so we should get a lot of marks. Same thing goes if you're wrong.

Anyway, best of luck tomorrow!

*Angel*

But I'm not wrong (prob will be now)

Yeah good luck to all the Tech Drawers out there.

Breezer

Q1 mostly right (at least half of part c, maybe more)

Q2 fine except I made it ten times more difficult by not reading the question. Instead of making one chord twice the other one I did an "angle at the centre is twice the angle at the circumference when standing on the same arc" job on it

Q5 my locus went through the ground (!) but I'm hoping I just messed up a point or something.

Q6 everything except the tangent to the parabola, which is annoying cuz it was an entire part and this is supposed to be my best question.

Roll on paper 2 and please be easy!

Cina

Hmm, it was most certainly not a very high cone for Q3. I had that at first aswell but then i realised I was doing my lokai off the wrong points and the final cone worked out to be about 25mm smaller than Cone A. Touching the sphere 33mm above the ground and in contact with the Cone at point P.

*Angel*

Cina wrote:

Hmm, it was most certainly not a very high cone for Q3. I had that at first aswell but then i realised I was doing my lokai off the wrong points and the final cone worked out to be about 25mm smaller than Cone A. Touching the sphere 33mm above the ground and in contact with the Cone at point P.

Yey I'm now backed up.

Damn it!!!

Well a lot of people made that mistake so hopefully they'll be nice when they correct it!!


Anyway, best of luck tomorrow Cina.

OTliddy

I wouldnt describe my cone as very high, but I think it was a bit higher than cone A. Damm!...ye all seemed to have done so well...i was hoping for an A between the 2 papers but that seems to be out the window now .

*Angel*

Out of interest is their many girls in your td classes, in mine there is one 5 out of around 24. Which I think is pretty pathetic.

*Angel*

OTliddy wrote:

I wouldnt describe my cone as very high, but I think it was a bit higher than cone A. Damm!...ye all seemed to have done so well...i was hoping for an A between the 2 papers but that seems to be out the window now .

Hope is not lost, you can still lose 60 marks between the papers and still get an A.

OTliddy

In my class of 15(around) there are no girls. However, in my music class, there is only one other boy

*Angel*

OTliddy wrote:

In my class of 15(around) there are no girls. However, in my music class, there is only one other boy

Terrible! You're so deprived. It's kinda weird how certain subjects don't appeal to different sexes.

OTliddy

*Angel* wrote:

Terrible! You're so deprived. It's kinda weird how certain subjects don't appeal to different sexes.

Yeah, it happens in extremes. In physics class if 17, there are 3 girls.
There are 40 people in the year doing music,only 4 of whom are boys.
Strangely, i got put in high female Irish and English classes. In both there are about 25 people of only 4 are boys. I'm not complaining.

sock.rocker*

Cina wrote:

Hmm, it was most certainly not a very high cone for Q3. I had that at first aswell but then i realised I was doing my lokai off the wrong points and the final cone worked out to be about 25mm smaller than Cone A. Touching the sphere 33mm above the ground and in contact with the Cone at point P.

yeah, i got that too.. i knew the logic of doin that question but the first time i tryied, i was takin the locus from the wrong points which gave me the high cone people are on about here

i went back to it though, restarted and got it out..

to get the true angle, do ya take an auxilary along the horizontal trace? thats what i did.. bout 60 degrees i think

Beno

Q1 (C) i drew a horz line from d to edge abc then brought that back to plan which gave me a line through plane abc

Then i drew a cone 40d from plane abc to d. Then i drew a xy parllel to plane abc where i got a circle from the cone
Bring these heights back from circle to abc then to the plan which should give you an elipse in plan
There this cuts the first line you drew on abc in the plan gives you the point where it hits the plane abc. Bingo you have ur line
That how i did it anyway
Fairly happy with the paper, stayed to the very end (examiner gave us an extra 20min) only did 4 q though couldnt do 7

P.s my new cone was about 20 higher than the other one and about the same diameter

Beno

Beno wrote:

Q1 (C) i drew a horz line from d to edge abc then brought that back to plan which gave me a line through plane abc

Then i drew a cone 40d from plane abc to d. Then i drew a xy parllel to plane abc where i got a circle from the cone
Bring these heights back from circle to abc then to the plan which should give you an elipse in plan
There this cuts the first line you drew on abc in the plan gives you the point where it hits the plane abc. Bingo you have ur line
That how i did it anyway

That sounds familiar!


But you examiner gave you an extra 20 minutes? Wtf?!

Beno

she was a bit busy with all the bags and papers and talkin to a couple of the lads about how they did next thing u knew it was 10 to

*Angel*

Beno wrote:

examiner gave us an extra 20min

Nice for some, I would have done an extra question.

Beno

spent 30min lookin at Q7 but just couldnt do it

sock.rocker*

Q7 was good except for the very end.. cudnt get the other pyramid at all.

*Angel*

sock.rocker* wrote:

Q7 was good except for the very end.. cudnt get the other pyramid at all.

I thought before hand that the oblique would be quite hard, however I was surprised with when I first looked at it I thought it looked easy, 'a' and 'b' were, then I saw 'c' and it was couldn't actually believe they'd thrown that in, it made the question quite a lot longer, thankfully I had time to spend a while on it, and I'm pretty sure I got it in the end, definitely a bit :eek: though.

sock.rocker*

i got an auxilary of the secong pyramid but i cudnt figure out how to take it back to plan.. i sat for so long staring at it at the end and cudnt figure it out

Webmonkey

I just hope i've passed it ...

daxon

i had a huge cone that went off the page.i thought this couldn't b right. so i just drew a smaller one at the same angle.i picked any height.
then it worked for me.

Q7 was a disaster..

i hav 4 desks to myself.i set up all pages 15mins before the test.so i really do save on time

*Angel*

daxon wrote:

i hav 4 desks to myself.i set up all pages 15mins before the test.so i really do save on time

I some how ended up with 3 desks, I only set up the first sheet before hand, did you put the sheets one on top of the other? I do that a home but it kinda leaves a 'spongy' feeling when you're drawing, hence the lines are less sharp.


I was thinking though it has to be one of the easiest exams to cheat in, if it weren't such a broad topic, because you're given the sheets before hand, all you have to do is stick a few sheets in under them and you're sorted. And you're shuffling through you're sheets during the exam so it wouldn't look suspicious at all. However it's too hard to predict what's coming up and cheating is wrong!

OTliddy

I put the second sheet below the first for the skew lines bit and punched holes with my compass through the points A,B,C and E. I bet a load of posts follow saying "duh, everybody knows that trick".

That extra twenty minutes isn't fair. Time was a factor for me and I could have finished Q7(c) if i had another 10 minutes

StupidLikeAFox

OTliddy wrote:

I put the second sheet below the first for the skew lines bit and punched holes with my compass through the points A,B,C and E. I bet a load of posts follow saying "duh, everybody knows that trick".

I didnt

jacksie

i was fair flying through the paper, at 20 to 12 i had interpen just set up and was like **** ill never get it done. so i went into overdrive to get most of it done, at 12 i was ready to tidy up when realised i had extra 30 mins.. lol.. pwnd most of it then:D:D

hum

hey guys,
i thought the exam today was pretty good, i stuck to my time and managed to get it all done so i was happy enough. some parts were a little tricky like 1 c but generally i thought it was a fair exam..

and Angel thanks for that tip about getting loads of sheets at the start, it saved me about five minutes! the examiner thought i was a bit crazy though!!

i did the loci question and i was really happy with it, what did everyone else think?, i thought it was an easier loci than other years, hopefully paper 2 will be ok too!

cant believe its almost over now, i have tomorrow then off for a week then in on the last day for engineering!

Alan G

For the cone in tangent planes I got a Steep Cone aswell and taller than cone A....
If it touches the sphere @ 33mm from the horizontal then you must draw a tangent to the sphere at this point - where this tangent touches the xy transfer it down to the plan and draw this radius from the centre of the sphere - this is where the distances start for your tracery centre!! It came up before in a previous year & i did it recently and thats the way to do it - so if you got a steep cone - i'm almost certain it's right!!

Cina

Then your cones are prolly right, but so is mine, the method was right and it contacted all necessary points. Maybe it was pissible to have a few types of cones that worked out.
Either way .. Paper 2 now.

I think it is, as you only have two points in plan of which you have to make a circle. But you need 3 points to make a circle. So maybe there are 2 possibilities.

Anyway, get off the computer and do some CRAMMING!!!

*Angel*

So what did you guys think of paper II?

Slightly harder than Paper One imo, but I think I did well.

It was a very fair paper. No questions that seemed complicated etc.

*Angel*

Yeah I think it was harder, what questions did you do?

I did:
- Mining
- Roads
- Roof
- Hyperbolic

I made a really stupid mistake with the plane director in hyperbolic, stupid stupid me, worse still I realised just as I was handing up my exam.

Perspective looked interesting...

I did:

Mining: I think I got all of that right.

Roads: Did pretty good. I'm not sure if I took the right approach to the shape thing as the lines weren't perpendicular to the road.

Hyperbola:A VERY easy question. I hope for full marks.

Shell: I chose this over the perspective as perspective takes me longer and I was a bit short on time. I regret the decision. That was VERY hard, although I may have got it right. I guessed one of the steps but it came out right so hopefully I got lucky.

All in all, a good exam.

hum

i did
perspective
roads
shadow
skew bore holes

i was kinda annoyed with the perspective, its usually my best question but this years was pretty hard, i could finish one part of it..

roads was pretty stantard i think... hopefully i didnt do too bad.

shadow was a really nice question i think it was pretty easy

skew bore holes was ok too..
i wouldnt say i did as good in this than i did in paper one.. i was kinda expecting it to be a little thougher but hey its over!!

im off for a week now then in next friday for engineering!

OTliddy

he he he the engineering paper was very easy. If only I didn't do so bad on paper1...

Cina

Did Perspective, Roof, Low Saddle (the hyberpola yoke) and roads.
Got everything right except for the end elevation of the hyberbola don't think that was right. Perspective was a bit hard imo, but I got it done perfect, took the best part of an hour however.

jacksie

Deleted User wrote:

I did:

Mining: I think I got all of that right.

Roads: Did pretty good. I'm not sure if I took the right approach to the shape thing as the lines weren't perpendicular to the road.

Hyperbola:A VERY easy question. I hope for full marks.

Shell: I chose this over the perspective as perspective takes me longer and I was a bit short on time. I regret the decision. That was VERY hard, although I may have got it right. I guessed one of the steps but it came out right so hopefully I got lucky.

All in all, a good exam.

exact same really

eoinmurphy

To be honest, I found this paper easier than the first. I dunno why? normally its the other way around and I suppose I'm just happier about this one cause I messed up big time with solids in P1.

I did:
Roof
Mining
HyperBolic...
Road

Roof was amazing, they litterily told you what to do step by step,
Minig was grand, I think I got (B) and I ran outa time but got most of (c) done,
De saddle thingy was easy, I did something where I joined the diagonals in plan to give me some wierd points to get the heights for the edges in plan(you know above D and
Road was grand, but there was one wierd bit at the upper left corner of the car park thingy, any one else get that??

All in all, it was a good paper.

P1 was good aswell, apart from the fact that I couldn't get my head around de solids in contact.
Loci=easy
Conics=easy
Inter PLanes=easy

I'm pretty pleased. So are the rest from my school, well.. most of them.
I'm glad to hear that you can drop 60 points and still get an A. I was worried there for a while.

But now its all gravy...........