symetry help

[LT72884]

Ok, so the homework is to build a block with 30* angles on each side and everything is supposed to be symmetrical around a center line. I follow the movie and book to a T and it will not work. The movie and book show the two very upper vertices being selected like i highlighted.
View attachment 4781

The book says click centerline and then the lower two vertices and then centerline again and then the two upper vertices as the lines indicate. the arrows appear just like they do in the book.
View attachment 4782
The next step is to select all three outside strong demnsions and then modify them all at once using the lock scale feature. I change the width to 20 and the others in the window scale down to the same as what the book says, however, the actual sketch is way muffed up. i hit repaint just to make sure. Oh and the undo feature always dissaperes after i save my project or add a new dimension. i have had to start from scratch 4 or 5 times because the undo feature just grays out.
View attachment 4783i made sure that that one particular verticy was selected. Notice how the modify window says 7.x but the image shows 62.x?? i tried for 3 hours to get it to work, either both the right and left go sky high or just the left. i wish i could record what im doing to show you all. This is very anoying that i cant even get simple things done.

thanx


Edited by: LT72884

 

[ReinhardN]

The click sequence for each symmetry constraint is centerline-vertice-vertice.
There is one constraint missing, the middle vertices in your sketch at the weak dimension 62.75. There are no arrows to be seen.
Reinhard

As a sketch must be fully constrained, ProE generates its own weak dimensions.
A sketch should be completely constrained by user, no weak dimensions to follow your design intent.

Edited by: ReinhardN

 

[LT72884]

The click sequence for each symmetry constraint is centerline-vertice-vertice.
There is one constraint missing, the middle vertices in your sketch at the weak dimension 62.75. There are no arrows to be seen.
Reinhard

As a sketch must be fully constrained, ProE generates its own weak dimensions.
A sketch should be completely constrained by user, no weak dimensions to follow your design intent.

dang it. Thats what i did. i grabbed all three dimensions and made them strong.

the book and video show and say "Make all dimensions strong corresponding to those in figure 5"

here is figure 5 from the book. which i added my text to. the video and book show the arrows in the exact same spot as to what i have with the same three dimensions set to strong. figure 5 does not show the 62.76 as a strong dimension. its still in grey color and says weak next to it. I wish the video and the book knew what they were doing. haha. thanx

figure 5 from book below
View attachment 4786

 

[kdem]

Actually I think the problem is that you don't have the 62.76 dimension in the modify dimension list. Check what happens when you have all four dimensions in the list with lock scale selected.
Edited by: kdem

 

[LT72884]

Actually I think the problem is that you don't have the 62.76 dimension in the modify dimension list. Check what happens when you have all four dimensions in the list with lock scale selected.

i just did that it it turns to a wine class shape. However, i tired it exactly like i did last night and this time i get a tuning fork shape. its almost like the program is messed up. My undo feature wont work 80% of the time, as in, when i make all the dimensions striong, it wont let me click undo or CTRL Z. the feature is greyd out and i cant save sometimes because the navigator greys out and i cant select where i want to save.

im goignt o try and record it and then put it on youtube to paste here so you can see what im doing. I called my friend and he walked me threw it but same thing happens.

thanx guys

 

[kdem]

When you get the wine glass shape do you have an angle dimension in your sketch as shown above? A video would be good but you're right either the directions are incomplete or you're missing a step. Can't say which since I don't have the directions you're using.

 

[LT72884]

Ok, here is the video, i dont have screen capture so it was done of me phone. i tired to explain the best i could. hopefully the res aint to bad. maybe somehow i can upload the video. it will only be a partial part of the lesson.

I am not selecting the angle dimension at all, just the three that i have outlined.

Whats strange is, in the video instructions, it shows the 131.27 dimension after he sketches the shape. in my vidoe below,If i middle click to briing up dimensions, that one is not there until AFTER i add the center line. Probably no big deal just an odd thing.

http://www.youtube.com/watch?v=gAdxNJLP0WM

this next video is the tutorial i am following. in no way am i distributing the whole video. just a partial of it for learning purposes only. i paid for it so the fair use policy allows me to display parts of it.

http://www.youtube.com/watch?v=S6U9VabFI9Y

i do everything this video says. notice on his though, the dimension appears right after he sketches it but on my video, it aint untill after i put the center line. you will see what i mean.

thanx guys.


Edited by: LT72884

 

[ReinhardN]

As nobody here has your book you should tell us how the sketch should look after scaling, I think it should keep its appearance and be larger/smaller.
You say "everything is supposed to be symmetrical around a center line", but your sketch isnt, the vertical lines are 61.63 resp. 76.63 long.
Apply the symmetrical constraint to the remaining vertices and the weak dimension will go away. Scaling will work then.
Reinhard

 

[LT72884]

As nobody here has your book you should tell us how the sketch should look after scaling, I think it should keep its appearance and be larger/smaller.
You say "everything is supposed to be symmetrical around a center line", but your sketch isnt, the vertical lines are 61.63 resp. 76.63 long.
Apply the symmetrical constraint to the remaining vertices and the weak dimension will go away. Scaling will work then.
Reinhard

i applied the constraints to all vertices and i get an error saying that the constraints interfere with other vertices. The shape is supposed to stay the same but smaller.

i have posted the video i am following. i also posted my video i made.

 

[kdem]

Okay looking at the video of the tutorial you're following there is a missing step. If you look at the video at 2:32 notice the weak dimension on the left legs of the sketch. The person providing the instructions misses a step so it looks like the video is spliced together. If you look at the frame at 2:35 where he is starting to select the three dimensions for modification notice the weak dimension is gone but there is a symbol (L with an underscored 1) next to to the left and right vertical legs. This is an equal length constraint which the person doesn't mention you need to create.
Edited by: kdem

 

[LT72884]

Okay looking at the video of the tutorial you're following there is a missing step. If you look at the video at 2:32 notice the weak dimension on the left legs of the sketch. The person providing the instructions misses a step so it looks like the video is spliced together. If you look at the frame at 2:35 where he is starting to select the three dimensions for modification notice the weak dimension is gone but there is a symbol (L with an underscored 1) next to to the left and right vertical legs. This is an equal length constraint which the person doesn't mention you need to create.

I knew something was missing. haha. thanx for pointing that out. So i guess i have to use the equal length constraint and then pick the two vertical edges?

thanx for noticing that. i would have never seen that. the book doesnt even say that, let alone how to do it.

 

[kdem]

So i guess i have to use the equal length constraint and then pick the two vertical edges?

Yes, you will then have a sketch that has the three linear dimensions and an angle.

 

[LT72884]

So i guess i have to use the equal length constraint and then pick the two vertical edges?

Yes, you will then have a sketch that has the three linear dimensions and an angle.

WOW, it actually worked. This kinda bugs me that the video and book left that out. I would have never figured that out if it was not for this forum. Thanx Kdem

now its time for me to figure out the other issues. lol haha



Edited by: LT72884

 

[TonyJager]

I am sure it was an exercise to add constraints.
however there is a another way of doing this. If you know you have a symetrical part you could just draw the centerline, then draw one half of the geometry from the centerline, highlight the geometry and select the centerline you want to mirror about.
Add add or delete dimensions.

 

[LT72884]

I am sure it was an exercise to add constraints.

I agree, but a hint would have been really nice. Especialy when the right side stayed symetrical and only the one vertice did not, i would have never ever guessed to use equal length symetry. Im just trying to figure out why i did not have to add an equal length constraint to the upper and lower horizontal lines? but i had to add it to the two vertical lines!..

however there is a another way of doing this. If you know you have a symetrical part you could just draw the centerline, then draw one half of the geometry from the centerline, highlight the geometry and select the centerline you want to mirror about.
Add add or delete dimensions.

I was thinking of this last night. #ds max had a simular feature back in the day. The last time i used 3ds max was in 02 during my high school years.

thanx