Technique help needed

[King Azog]

Hi everybody! I'm Luca from Italy, new member of this illustrious comunity and long time Lego fan. After a long pause in building lego castles, I found LDD and I switched to virtual building. Please forgive my bad english.

Now I'm here to ask some advice to build a truncated icosahedron (roughly a sphere built with polygons) with nexogon part (not a MOC. I've seen on the net and I'd like to buld it for my next spaceship). I've some troubles with angles and fixing parts toghether: it seems that hinge aligne tool doesn't works. I attach an image for you all and you can find the lxf file here.

Thank you in advance for any help. Have a nice day,

Luca

[SylvainLS]

LDD’s “hinge align tool” causes more problems than it resolves.  It moves all the parts, especially those you don’t want it to move, and it crashes.

The best approach is to calculate the correct angles yourself and enter them with the “hinge tool” (not “align”).

[King Azog]

Thank you SylvainLS. Yes, Hinge align tool is a very complex tool to use. My problem is just that you wrote: calculate the correct angles... I always come near to connect pieces but they don't. Is for this reason that I've asked help or advices. Thank you.

[SylvainLS]

I mean you need to do the Math here, with the parts’ exact geometry.

Those angles are not necessarily “regualr” / all the same.  Like on the picture below that shows the angles one needs to use to make an hexadecagon (16-sides polygon) in Lego with 4-studs-long sides.  A regular hexadecagon would have 22.5° angles (that is, 157.5° and 67.5° instead of the ones in the picture) but it wouldn’t fit in the Lego system.  With the angles shown in the picture, the arc fills an 8 studs by 8 studs corner.  The hexadecagon will have 4 sides (horizontal and vertical) “in System” / that can attach on a baseplate (20x20).  (The hexadecagon is an example.  It doesn’t apply to the icosahedron.)

Also note that with real bricks, there’s a tolerance that often allows connections that can’t work with “perfect” bricks, like in digital.  So you may be able to make a ring that connects correclly but not the whole sphere (that means you might have to leave a few parts not connected).

 

[King Azog]

That's the kind of help I need. Thank you SylvainLS. I'm not good at math and, yes, I know that from real brick and virtual brick there are differences. Thank you.