# Modeling Problem When I make a Bolt (stud bolt)

Hello, there. I’m Yustino who has problem with modeling in sketchup 2018 pro.

what I tried to do is making a studbolt size of M16(metric) about 20~30mm long.

This is my procedure.
(1) make Half circle (from circle, Ctrl+ 50 segments)
(2) move 0.75mm one end only of ‘(1)’ along blue axis
(3) copy ‘(2)’ and rotate 180 degrees and them make them meet at one end
(4) copy & array ‘(3)’ along blue axis as many as I want
(5) make ‘(4)’ a group, rotate & copy 180 degrees about blue axis

now, I have two groups of spiral curves

(6) make circle section, make the circle as a group
(7) extrude ‘(6)’ to be a column has the same center & height with ‘(5)’

(8) explode ‘(7)’

here is my problem
(9) explode one of spiral curve group, I got modeling problem as shown picture I attached above.
it looks like… several tooth pulled out.

this is my environment
win10 pro
Nvidia GTX1060
Surface book2

You’re working at too small of a scale. Scale up by 1000. Set units to meters but think millimeters. Or use the Dave Method.

I think there are some other issues you’re creating. Instead of 50 sides, use a multiple of 12. 24 for a half circle is likely more than enough.

Here’s an example done with 48 sides for the entire circle.

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The method as you describe it can’t work. When you raise one end of a semi circle you are basically rotating it which means the endpoints of the segments will not line up, so they won’t break the cylinder faces. This can be seen in your image, the spirals disappears behind the face rather than follows it.
The manual method for making a helix is to use one segment and lift one vertex along the blue. then radial and linear array to get multiple helices.
I have a demo video somewhere, if I can’t find it I’ll make another one.

And you need to do as @DaveR says, scale up or use the Dave Method.

Edit: This is one I made long ago just to show the method. Ignore the last part with the scaling as it’s not relevant to making your thread.

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@Box, I’ve watched it over and over again the gif animation, but I did not understand how the lines are joined. How do you join lines? Are you using a plugin?

Yes, that is why I said to ignore the last part.
In the gif I zoom out (before extruding the circle) and select all of it then you see a red flash of the edges, that was a keyboard shortcut for weld.
You don’t need that for making thread as you can select the faces of the spirals and scale them.

I’m using “smustard_Weld” to join lines. But the lines do not merge as you do. Therefore, I would like to know which plugin is this.

Fredo’s Curvisard.

Thank you so much.