Making screw caps and nuts

[ivla]

Making a simple screw cap with "thread" primitive.

Make the helicoid thread object:

Extrude upper non-flat face by Y axis, not by normal (!!!) :

Repeat with lower face:

Flatten those faces by Y:


Inset both faces:


Scale (enlarge) both of them radial by Y axis

Use "Absolute scale" to set size of upper face:

And repeat with the lower (with same size by X & Z):

Select upper and lower faces and use "bridge"

Select whole oblect and "Invert" it:

Select faces on lower end of object and extrude it by Y axis

Unlesect all, select faces in the inner surface:

"Dissolve" it

All done.
Below I cutted the cap in half to show what's inside it:


Same process can be used for making nuts, but it requires to modify the initial oblect (dissolve some faces in its lower - smaller - end) and does not require last steps (extrude & dissolve).

Modifying thread primitive for making nut:

Select lower - smaller - face, then "Select more" (by presing "+" key):

"Dissolve" it:

Select those two points and "Connect" it:

"Connect" another two points:

Primitive is ready.
To make nut extrude upper and lower faces etc., as shown above.

[Xavier]

Thanks Ivia, it was helpfull!.



Wings 3D file: (Right click on the link & "save the link as...")
  BoltsAndScrews.wings
M3/ M4/ M5/ M6/ M8/ M10/ M12

[ivla]

M3/ M4/ M5/ M6/ M8/ M10/ M12

About "standard" metric screw thread.

There is plug-in for scripting in Wings3d by edb:
http://www.wings3d.com/forum/showthread.php?tid=3096
In the last page I placed a script for generating the profiled thread (metric ISO/DIN13 and some simple profiles).

Take a look.

[ivla]

...and about using "booleans" for making nuts: it may crash if there is too many faces, some thousands or even more - like blue ring here:

[ivla]

Update: making nut with thread generation script from there.
(orange is a selection color here)

Make thread object with "internal" (it's important!) thread


Select upper face and extrude it by Y (not by normal!)


Flatten upper face


Deselect upper face, select lower and extrude by Y


and flatten it


Select both upper and lower faces and inset it


and scale it radial by Y to the desired size (you can also use Absolute scale for it)


Bridge upper and lower faces, you get an "inverted" object


Select whole object and invert it


Both ends of thread looks like here: