hi
i am planing to build a V4 dome with a 3m radius.
i calculated the respective strutlenghts,thanks to the online calculators (http://www.geodomehome.com/domeformulas.htm) but what i can''t figure out is the angle of the ends or the conectorpieces.
i will weld strip to each end which has a hole to conect the strut to the others i attach an image to explain.
i understand in a V4 dome there are 6 different struts and each has a different angle on the ends, right?
how do i calculate these angles?
thanks
frank

[ Comments 17 ]

posted by
simon

29/01/2009 22:28:42

Hi Frank

It's 173 degrees for the shortest strut, 172 for the next two shortest struts, and 171 degrees for the three longest struts.

You can work it out by hand with trigonometry, but vector calculus is much more general, though you need to code that up somehow.

Simon

posted by
frank

30/01/2009 12:41:13

simon,thanks for this response.
would you mind confirming if my calculations for a V3 dome of 3m radius are correct (i sill have not decided between the V3 and V4
strut A(shortest) 170 degrees
strut B 168,3 degrees
strut C 168 degrees
thanks for your help i appreciate it
frank

posted by
simon

31/01/2009 00:24:40

Hi Frank, yes, that's what I make it.

Simon

posted by
frank

02/02/2009 14:41:20

hi,
thanks for the confirmation!
if you don´t mind i´ll keep on asking. i would like to avoid mass- missproduction.
i attach an image of the 5way hub, which is the easy part i guess, because when i look at the other hubs, 4 and 6 ways i see they are not all equipped with the same angles, there are 4way domes that have to have angle for strut A,B and C and there are 4 way hubs that have angles for only strut C and so on, i take as refference the V3 colorcoded image in the dome calculationtools.i have changed the design a bit, so this detail now becomes important i guess. is there a calculationtool that not only defines how many 4 way hubs but also how many of each type? same for the 6way hubs
thanks

posted by
simon

02/02/2009 19:04:42

Hi Frank, I haven't seen such a tool. I've written a very general tool myself and it wouldn't be very difficult to add this facility, but I haven't got round to it and I'm not actively working on it at the moment. You're welcome to the source if code Java.

posted by
rui

04/05/2009 01:14:06

can someone tell me a site to calculate measures of quantity and length of iron to build elliptical dome in the frequency v4, v5, v6, v7? see the elliptical design that need to build.
Regards

posted by
rui

04/05/2009 01:16:22

can someone tell me a site to calculate measures of quantity and length of iron to build elliptical dome in the frequency v4, v5, v6, v7? see the elliptical design that need to build.

posted by
Admin

04/05/2009 01:27:45

Hi Rui,
That looks like an elongated 3v dome. much simpler to build than an eliptical dome. Not sure what's happening with the base triangles, you seem to be getting some odd shapes. Have you tried the desert domes calculation pages, I think they go up to 5v.

You shold easily be able to calculate the struts yuo need for the center section of your streched dome, Have a look at this page for a 2v version: Elongated dome design

posted by
simon

04/05/2009 22:53:39

It's interesting, isn't it. It's basically a 2v dodecahedral, with a bit spliced into the middle.

posted by
simon

05/05/2009 12:23:33

The brown mesh is a 2v dodecahedral, sliced vertically at a mid-plane and reflected. The red mesh is a cylinder with the same diameter as the dome ends. The green-circled vertices are on the dome's mid-plane so the cylinder joins the dome at these points, and the yellow struts just stitch the other vertices together.

posted by
admin

06/05/2009 19:19:55

I thought it looked like a 3v? The whole thing needs to be rolled forward so that the bottom front row of panels is lost. Then you would loose those messy bits of triangles at the ends.

posted by
simon

07/05/2009 12:00:20

Hi Paul

I'm not too sure about the frequency nomenclature for a dodecahedral dome - I've assumed a 1v starts with the pentagonal faces divided into five triangles, but is that really a 2v?

Like you say, if it was rolled round 90 degrees it would be better.

It's not obvious how this extends to higher frequencies viz the regular spacing of the red horizontal struts and the way it mates with the geodesic.

posted by
rui

06/06/2009 21:07:44

hello admin. grateful for your comment. I entered the site of the desert domes "dome calculator" up to 6v. the calculations only for geodesic dome. there is a site to calculate summits with other formats? I do this with tunnel dome 30 meters wide by 50 meters in length 5v

posted by
simon

20/08/2009 12:20:03

how to solve the tan 2°, sin 10°, cos 5°

posted by
Mauricio

15/06/2011 08:23:47

hola, estoy contruyendo una cupula 2V sin conectores, solo con triangulos, como se ve en el video, queria saber como puedo determinar los angulos de cada puntal para formar el triangulo o mas bn, para formar los 2 triangulos que contiene la cÃºpula
se los agradeceria mucho.

posted by
Alligatorsoup

23/08/2012 06:57:35

If I want a shallow pitch dome as in a 4' rise over 30' as opposed to a 25' rise over 30', is there a dome calculator set up for designing the strut lengths in varying frequencys currently available?
Thank you.
Alligatorsoup