Working with Sketchup in between beginner and intermediate skill level can be a back-braking adventure. I was exited after the first steps when it was so simple to extrude three dimensional objects in no time. But it doesn’t stay that simple. Going to the next level requires a lot of in-depth knowledge, fiddling around with plugins and watching hours of video tutorials. For one of my projects I had the need for a custom case that could be closed with a threaded plug. I found a lot of tutorials but none of them fully worked for me. This is how I’ve done it:
- First install the following Sketchup extensions ( you can find them by searching in the sketchucation user forum):
- Helix Plugin
- Right Up Extruder
- Draw the profile of your thread on the green axis. I draw everything in millimetres multiplied by 100. This avoids issues in sketchup when working with very small faces. The Profile is created by sketching 3 lines and rotate the the two lines parallel to the red axis by 30 degrees so they form a triangle. I then redraw one of the rotated lines to create a surface.
- Insert a horizontal line and devide it into 7 part to find a spot for cutting off the tip of the triangle. You can of course vary this depending on how much you want to flaten your thread.
- The tip and the remaining middle line are erased and the thread profile is ready for extrusion.
- Now create a helix (Draw -> Helix menu) and choose the appropriate values. I used 1500mm for the radius, 120mm pitch and, 4 rotations and 48 sections for this example. If you want to print your screw later on make sure you choose min. 48 sections otherwise the printed screw would have visible edges.
- Rotate the thread profile and move it to the start of the helix by connecting the middle of the thread profile’s right edge to the start of the helix start point.
- Explode the Helix group and mark all – helix and thread profile by tripple clicking
- Extrude thread by choosing “Upright Extrude” from the Extensions Menu
- Reverse Faces and create a component “thread”
- On the red axis draw a circle starting from origin to the extruded thread connecting exactly the middle of the thread’s “left” edge. Make sure your circle consists of 48 sections. This can be set when you initially select the circle tool by just typing “48” in the measure bar.
- Push the circle in both directions to become slightly higher than your thread.
- Mark the bolt and create a component called “bolt”.
- Check both components individually with the Solid Explorer to see if they are “solid”
- Select both components and create an Outer Shell. Tools -> Outer Shell
- Check again of the newly created component is still solid.
- Select the component and use the Scale-Tool to scale the threaded bolt down by 0,01 to its original size.
The model can now be exported to DAE or STL file type, imported into your 3D printers slicing software and finally printed out. Happy printing!All Posts