First of all excuse me for language skills (I try my best)
I want to build a dome in segments or elements, i.e. triangles manufactured in my workshop and later on put together to a dome. No struts or hubs used.
I am in progress of building a small model of 2v dome. It is built of 10mm board. I belive I have solved all matematichs.
My future project will be a greenhouse of wooden framed triangels fitted with glass.
The problem i need help with is the angles between panels the dihedral angles for 3v domes.
Can somebody help me were to find these or how to calculate them

[ Comments 33 ]

posted by
simon

27/08/2009 19:51:53

p12

For a 2v, bevel all the edges 11 degrees except for the long edge of the pent panels, and you bevel that one 7 degrees.

For a 3v, bevel all the edges 7 degrees except for the long edge of the smaller triangle, and you bevel that 4 degrees.

I think.

posted by
p12

29/08/2009 22:56:00

3rd attempt, so sorry, beleive my keyboard causes the errors
Simon
Thank you for your answer. May i post another question to clarify my needs. I have not found anywere how to calculate dihedral angles in 2v domes. I have tried to solve the calculations myself. The calculations regarding dihedral angles i have done results as follows:
Dihedral between x-panel and y-panel to be 161,97 or or approx:162 (180-162=18). 18 total to be beveled , divided between x- and y-panel as follows:
x-panel bevel = (90-82,78 =)7,22 or approx: 7
Y-panel bevel = (18-7,22=)10,78 or approx: 11
Dihedral angle between x-panels 157,54(180-157,54=22,46) 22,46 total to be beveled. In this case 22,46/2=11,23 from sides next to adjacent x-panel
So your answer of using angles 11 and 7 are same as my calculations. But if you use decimals, is it any difference from my figures?
Best regards

posted by
admin

30/08/2009 02:49:51

Hi P12, you could of course adjust the dihedral angle by making the struts slightly longer or shorter. I build 2v domes that have all dihedrals at 10 degrees, and 3v domes with all 6.5-degree dihedral angles. As you go up in frequency the angles between different dihedrals gets smaller so it's even easier to make them all the same. I will in due course be adjusting the dome calculations tools on the site to make all dihedral angles equal, this will make the headache of dihedral angles hopefully a thing of the past. If your interested I'll post details.

posted by
p12

03/09/2009 21:41:10

First of all , great thanks to simon and admin for taking the time to help me
Second , Note: names of triangle sides, panels etc all from 2v calc tool here
Third, Spelling and grammar could be doubtfull, i hope thet does not distract from the subject..I belive in the importance of angles made as close as possible to calculated (if my calculations are correct) angles. The origin of the dome is the carbon 60 molecyle. It has its strengt in the c60 similar structure..in case of building a dome i beleive stress factors such as distubution of forces as well as shear forces between panels will be better equal distributed in the structure the closer to the original c60 it is built. Of course it (number of decimals) has to be reasonable to be possible to constuct, i guess i can keep it within 0,5 degree (with more expensive tool within 0,1 degree). Who am i to open my mouth? I have so far only made models. I have no experience of bigger domes. I look in to it as a 3-D puzzle. I would like to make all pieces induvidually (various triangles). In this way put effort in to make them exactly identical and then put them together. My ongoing model project is at 2v dome. I first made one x-panel (a-sides beveled 11degrees and b-side beveled 7 degrees) and one Y-panel (b-sides only, all beveled 11 degrees), angles within less than 0,5 degree error. These were used as guides in manufacturing 30 x-panels that are exactly the same. Then also 10 y-panels.
It seems to me like most people build domes “on-site” ,.a bunch of wood pieces and hub connectors put together. In that case dihedral angles seems to be not so important. Only concern would be angles at strut ends to be joined in hubs. I felt like it would be nice to build triangles fitted with isolation, windows etc. All made indoors during winter, and later on put together and hub connectors not needed. This is why i am seeking the exact dihedral angles. And/or how to calculate them.

posted by
p12

19/02/2010 09:32:25

model project

posted by
p12

20/02/2010 10:38:15

I have tried to post pictures of my model project. I could not. I created a simple home page for this. h t t p://web.comhem.se/p12dome/

posted by
Trielsaiderve

17/05/2010 01:19:28

Hey i am new to this, I came upon this message board I have found It absolutely accommodating & it's helped me out alot. I hope to give something back & help other people like it has helped me.
Thanks, See Ya Around

posted by
Trielsaiderve

21/05/2010 14:48:53

Sup im fresh here, I stumbled upon this chat board I find It positively accessible and it's helped me alot. I should be able to contribute and aid other users like it has helped me.
Thank You, Catch You Later

posted by
blinnyAttaist

27/05/2010 05:39:40

Hey i'm fresh to this, I came accross this forum I have found It truly accessible & it's helped me a great deal. I should be able to give something back & assist other users like it has helped me.
Thank You, Catch You Later

posted by
Trielsaiderve

13/06/2010 16:26:49

Howdy i am fresh to this, I came accross this message board I find It incredibly useful & it has helped me so much. I hope to contribute & assist others like it has helped me.
Cheers, See You Later

posted by
Victor

01/12/2010 11:00:09

Hi,
First, congratulations for this fantastic site.
I have a doubt. I’m trying to design a similar 2v model, and If I bevel 7 degrees the long edges of the pent panels (X) and 11 degrees the remainder edges of X and Y panels, I will have a gap in the angles of both type of panels with the dome floor, because the Y and X panels will rest in the floor at different degrees (7 degrees for long edges of X panels and 11 degrees the Y panels). All dome panels should rest with the same degree. Isn’t it?
Thanks,
Victor.

posted by
p12

15/12/2010 05:43:45

comment to victor: i wish i could post picture to illustrate. there will not be a gap to the floor. the x and y panels are off a different height and then needs different angles when resting on the floor. both x and y panels will reach (the top point of triangle) a point that is one radius away from dome centrepoint . good luck with your dome project /p12

posted by
Dave

11/12/2012 15:01:23

I would definitely be interested in the calculation tool update where all dihedral angles along the long edges are the same. Is this a possibility? thanks.