Pete Bennett

Parabolic Dome

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Hi Guys it's me again. Can any of you please explain (in very simple English) how I can form a parabolic dome shape. I am designing a cabinet that is actually an Acorn, infact it is two acorns. I am fairly new to Sketchup so have yet to experiment with all the tools and their effects. I'm probably missing something obvious.

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The way I do it is as follow:

1. Draw a CIRCLE on the "ground". this will be your "turning tool" later on

2. Draw a LINE from the center of that circle to it's circumference (basically the radius of the circle)

3. Draw a LINE from the center of that circle "upwards" perpendicular to the previous line so that they form a 90 degree angle between them (this will be the center axis of the dome)

4. Draw an ARC from the end of one line to the other (does not have to be the end - could also be anywhere along their length and will be dictated by your desired dome shape as you'll see in following steps). set the curve of the arc match the dome shape you want to create:

post-10-0-17917600-1298306400_thumb.jpg

5. Now "TURN" that dome: SELECT the circle on the 'ground' (this will be used as the turning tool), then choose FOLLOW-ME tool (once Follow-me tool is selected, it'll use the previously selected circle as it's guide for the following operation), and click on the face made by your arc+2 lines and it'll turn the dome for you:

post-10-0-15521600-1298306514_thumb.jpg

This is really the simple explanation, my suggestion is to try it out, and play around with it to get the idea, and get more ideas as to what you can do with it. If you have any questions feel free to ask. I am sure others will jump in and add more suggestions and ideas.

Sharon

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The way I do it is as follow:

1. Draw a CIRCLE on the "ground". this will be your "turning tool" later on

2. Draw a LINE from the center of that circle to it's circumference (basically the radius of the circle)

3. Draw a LINE from the center of that circle "upwards" perpendicular to the previous line so that they form a 90 degree angle between them (this will be the center axis of the dome)

4. Draw an ARC from the end of one line to the other (does not have to be the end - could also be anywhere along their length and will be dictated by your desired dome shape as you'll see in following steps). set the curve of the arc match the dome shape you want to create:

post-10-0-17917600-1298306400_thumb.jpg

5. Now "TURN" that dome: SELECT the circle on the 'ground' (this will be used as the turning tool), then choose FOLLOW-ME tool (once Follow-me tool is selected, it'll use the previously selected circle as it's guide for the following operation), and click on the face made by your arc+2 lines and it'll turn the dome for you:

post-10-0-15521600-1298306514_thumb.jpg

This is really the simple explanation, my suggestion is to try it out, and play around with it to get the idea, and get more ideas as to what you can do with it. If you have any questions feel free to ask. I am sure others will jump in and add more suggestions and ideas.

Sharon

Thank you once again. However, is there any way I can soften the top of the dome a bit, it's rather pointy? Sorry to be such a pain but I don't really get a lot of time to play and I can see it's definitely a program to play with.

All the best

Pete

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Thank you once again. However, is there any way I can soften the top of the dome a bit, it's rather pointy? Sorry to be such a pain but I don't really get a lot of time to play and I can see it's definitely a program to play with.

All the best

Pete

Great method, Sharon. As always!

Pete, after you get the dome complete you should be able to use the MOVE tool to grab the top point and move it downward a bit. This would soften the tip, and all the faces should adjust by themselves. Be sure to just grab the very point at the top though.

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Great method, Sharon. As always!

Pete, after you get the dome complete you should be able to use the MOVE tool to grab the top point and move it downward a bit. This would soften the tip, and all the faces should adjust by themselves. Be sure to just grab the very point at the top though.

thanks guys. Can't get back to it before the weekend but, I'll give it a try. all I got to do now is figure how to make them in real wood.

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Thank you very much guys. Once I realized I was using the wrong 'move' tool? things worked well. Now all I have to do is make them Anyone out there an expert with Mercator's projection?

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