10-04-2023, 08:49 AM
Making a simple screw cap with "thread" primitive.
Make the helicoid thread object:
![[Image: 001-cr.png]](https://i.ibb.co/88HbK9W/001-cr.png)
Extrude upper non-flat face by Y axis, not by normal (!!!) :
![[Image: 002-cr.png]](https://i.ibb.co/Hnh0qbr/002-cr.png)
Repeat with lower face:
![[Image: 003-cr.png]](https://i.ibb.co/6sX9w6J/003-cr.png)
Flatten those faces by Y:
![[Image: 004-cr.png]](https://i.ibb.co/VVTQ889/004-cr.png)
![[Image: 005-cr.png]](https://i.ibb.co/9qtYvHk/005-cr.png)
Inset both faces:
![[Image: 006-cr.png]](https://i.ibb.co/SrvbdRW/006-cr.png)
![[Image: 007-cr.png]](https://i.ibb.co/qWnVGks/007-cr.png)
Scale (enlarge) both of them radial by Y axis
![[Image: 008-cr.png]](https://i.ibb.co/bBfMFGx/008-cr.png)
Use "Absolute scale" to set size of upper face:
![[Image: 009-cr.png]](https://i.ibb.co/Z8XL8Dh/009-cr.png)
And repeat with the lower (with same size by X & Z):
![[Image: 010-cr.png]](https://i.ibb.co/VvYs76X/010-cr.png)
Select upper and lower faces and use "bridge"
![[Image: 011-cr.png]](https://i.ibb.co/b3y2Jt5/011-cr.png)
Select whole oblect and "Invert" it:
![[Image: 012-cr.png]](https://i.ibb.co/kHL1jzf/012-cr.png)
Select faces on lower end of object and extrude it by Y axis
![[Image: 013-cr.png]](https://i.ibb.co/S5SgbkX/013-cr.png)
Unlesect all, select faces in the inner surface:
![[Image: 014-cr.png]](https://i.ibb.co/fpQ2bsq/014-cr.png)
"Dissolve" it
![[Image: 015-cr.png]](https://i.ibb.co/cw1TK3c/015-cr.png)
All done.
Below I cutted the cap in half to show what's inside it:
![[Image: 016-cr.png]](https://i.ibb.co/jR3FjSS/016-cr.png)
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:
![[Image: 101-cr.png]](https://i.ibb.co/3fN93mT/101-cr.png)
Select lower - smaller - face, then "Select more" (by presing "+" key):
![[Image: 102-cr.png]](https://i.ibb.co/rHV8VS6/102-cr.png)
"Dissolve" it:
![[Image: 103-cr.png]](https://i.ibb.co/KG0QxQn/103-cr.png)
Select those two points and "Connect" it:
![[Image: 104-cr.png]](https://i.ibb.co/wYSqRhZ/104-cr.png)
"Connect" another two points:
![[Image: 105-cr.png]](https://i.ibb.co/pdYWWXY/105-cr.png)
Primitive is ready.
To make nut extrude upper and lower faces etc., as shown above.
Make the helicoid thread object:
![[Image: 001-cr.png]](https://i.ibb.co/88HbK9W/001-cr.png)
Extrude upper non-flat face by Y axis, not by normal (!!!) :
![[Image: 002-cr.png]](https://i.ibb.co/Hnh0qbr/002-cr.png)
Repeat with lower face:
![[Image: 003-cr.png]](https://i.ibb.co/6sX9w6J/003-cr.png)
Flatten those faces by Y:
![[Image: 004-cr.png]](https://i.ibb.co/VVTQ889/004-cr.png)
![[Image: 005-cr.png]](https://i.ibb.co/9qtYvHk/005-cr.png)
Inset both faces:
![[Image: 006-cr.png]](https://i.ibb.co/SrvbdRW/006-cr.png)
![[Image: 007-cr.png]](https://i.ibb.co/qWnVGks/007-cr.png)
Scale (enlarge) both of them radial by Y axis
![[Image: 008-cr.png]](https://i.ibb.co/bBfMFGx/008-cr.png)
Use "Absolute scale" to set size of upper face:
![[Image: 009-cr.png]](https://i.ibb.co/Z8XL8Dh/009-cr.png)
And repeat with the lower (with same size by X & Z):
![[Image: 010-cr.png]](https://i.ibb.co/VvYs76X/010-cr.png)
Select upper and lower faces and use "bridge"
![[Image: 011-cr.png]](https://i.ibb.co/b3y2Jt5/011-cr.png)
Select whole oblect and "Invert" it:
![[Image: 012-cr.png]](https://i.ibb.co/kHL1jzf/012-cr.png)
Select faces on lower end of object and extrude it by Y axis
![[Image: 013-cr.png]](https://i.ibb.co/S5SgbkX/013-cr.png)
Unlesect all, select faces in the inner surface:
![[Image: 014-cr.png]](https://i.ibb.co/fpQ2bsq/014-cr.png)
"Dissolve" it
![[Image: 015-cr.png]](https://i.ibb.co/cw1TK3c/015-cr.png)
All done.
Below I cutted the cap in half to show what's inside it:
![[Image: 016-cr.png]](https://i.ibb.co/jR3FjSS/016-cr.png)
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:
![[Image: 101-cr.png]](https://i.ibb.co/3fN93mT/101-cr.png)
Select lower - smaller - face, then "Select more" (by presing "+" key):
![[Image: 102-cr.png]](https://i.ibb.co/rHV8VS6/102-cr.png)
"Dissolve" it:
![[Image: 103-cr.png]](https://i.ibb.co/KG0QxQn/103-cr.png)
Select those two points and "Connect" it:
![[Image: 104-cr.png]](https://i.ibb.co/wYSqRhZ/104-cr.png)
"Connect" another two points:
![[Image: 105-cr.png]](https://i.ibb.co/pdYWWXY/105-cr.png)
Primitive is ready.
To make nut extrude upper and lower faces etc., as shown above.