Another Dome Question

dc1999

Hello all,

I have another dome question. I have tried searching the forums and actually tried to follow a dome video tutorial (http://www.youtube.com/watch?v=-hj_I1s6qLw).

The problem is that sometimes I am able to create the dome with no issues, but sometimes the domes don't come out correctly at all and I can't determine why.

I have attached the two images of the problem so you can understand what I mean when I say the dome doesn't come out correctly. There appears to be extra lines in it as if the follow me tool went too far (however, I even tried holding down the Command key when using the follow me tool and still same results).

The weird thing is that sometimes I use exactly the same methods to create another dome and there is absolutely no issues. Why is this? What am I doing wrong?

For completeness sake, I have also attached my SKP file in case someone wants to check it out.

Any help would be much appreciated.

dome.skp

Gaieus

Hi DC,

I am not sure what went wrong in your version however what I noticed is that your base circles' segments are slightly misaligned from the blue axis. What I mean (see the screenshot) is that maybe you did not align the arc (that you lathed around) exactly at the diagonal of your circle because you may have clicked somewhere else following some inference.

I have rotated the lower tube so that its diagonal is on the blue axis and made a dome easily.
I deleted your original dome and though did not rotate it, making carefully sure that I draw the arc on the diagonal, I could make a perfect dome there. See attached file (I have unhidden everything but turned X-ray on so you can see through)

dome.skp

dc1999

Gaieus,

Thanks so much for the help! I did not realize that the angle at which you draw your circle matters. I just thought you pick a point for the center and then draw the radius. But it appears if you don't align the radius with an axis you can have some challenges down the road especially if you are using the axis to draw the arcs. Eye opening, and completely explains why I was having inconsistent experiences with my domes!

Many thanks again.

dc1999

Gaieus,

Thought of another question relating to this SKP.

You saw my box with two cylinders bored into it. What if I wanted to rotate one cylinder so that it would be at an angle (please see attached image)? So now I have part of the cylinder sticking out of the box and part of the cylinder no longer accessible because the face is not at an angle.

Is there an easy way to slice off any extruding pieces? Because I figure I can just move the cylinder until the whole opening is accessible and then just slice off the external pieces. Or is there another way to do this?

Thanks in advance!

Dome at angle.jpg

dome at an angle.skp

Gaieus

You did it correctly - grouped the cylinder first.

Now if you edit the group, close the hollow end, you can simply PushPull it until all the end rim is outside. OR you can move it out a bit along the red axis. Then select the side of the cylinder (still while editing), right click > Intersect with model. Erase that is outside.

Now exit the cylinder, select the face outside and the cylinder group and intersect selected (not model this time) then delete the elliptical face you get there.

dc1999

Gaieus,

You are the bomb! Worked like a charm. Thanks a ton!

Gaieus

Imagine I go off like a bomb!

architex

CAN anyone, please, to teach me how can I build some ELLIPTICAL DOME?

And what kind of plugin do I have to install inside Sketchup 2013?

I am a finish architecture student, who need urgently finish my last project work for University. But, I am stocked at how I build a steel frame structure for an elliptical dome.

Need really help, please, some one.

best regards.

António André
from Portugal

Dave R

No plugin required.

Draw a circle for the base of the dome.
Draw a half-circle arc for the height of the dome.
Run Follow Me to get the spherical dome.
Use Scale to adjust the dimensions to make it elliptical.

Screenshot - 3_24_2014 , 4_30_53 AM.png

architex

Hi Dave R.

Thanks for your answer.

1º - I already try it, but I miss how can I build the inside frame structure for support the dome. Try to think like "Gothic Arch" and its timber frames structures.

I need to build some structure for support that shape. And I need to show it in SU model.

if you need I post some images of the project, please ask, so you can see for your self better what I pretend to do.

http://imageshack.com/a/img812/9311/g4z6.png

thanks again.