I am a beginner in SketchUp so my questions might sound a little unclear and/or very basic to you guys.
There is one thing I cannot figure out on my own. So there it goes:
I am trying to create a part which I will 3d print afterwards. This part is supposed to fit an existing part of a pen and will be screwed on the latter. The existing pen part already has a screw thread. I have thought through my entire part but I cannot figure out how I’m going to reproduce the exact screw thread.
probably first thing is find a screw that fits the pen (take the pen to a hardware store)… if not, maybe there’s some sort of putty you can put in the hole, let it dry then unscrew it ? (hawtf)
you need some way to get the dimensions and i assume it’s easiest to use the specs for the exact screw… if not that then it will probably be easier to get the measurement from the molded screw as opposed to inside the screw socket…
if all else fails, just use a cylinder slightly larger than screw diameter, choose a softer print material, and screw it in
but after you get the right dimensions, it will be easier for people to show you how to model it properly in order for it to fit.
Perhaps you can get the thread specification from the manufacturer. This should give you the shape of the thread profile and the dimensions, from which you should be able to construct a 3D representation. For resources on how to construct screw threads, see The SketchUp Sage: Helical forms - spirals, screw threads and more.
A word of caution, though. Given the inherently segmented, polygonal form of curves in SU (including constructed helices), I am dubious that you’re going to get a mating thread that engages smoothly with the die-molded one.
Depending on how small the threads are and how high-resolution your 3d printer is, you may have better luck printing the part without threading and then using a tap or die to cut the threads.
If it is just a small detail in a larger model, you may never see it, or only need a general impression of ‘thread’ to view from a distance. In that case, a simple 2d FaceMe image might suffice.
If you draw one in full detail, and use lots of copies, it may overwhelm SU, and in any case will look almost solid black in anything except a very close up view.
There are other ways of giving an ‘impression of thread’.
One is to use parallel circles, separate from the cylindrical body of the thread, spaced wider apart than the real thread pitch. Don’t use more segments than needed to "look round’ at your viewing distance. The default 24 is usually far too many and will just bloat your file. Try 8, 12, or 16.
But if you do need full detail, or a more accurate ‘impression’ try one of the plugins to draw spirals - search the Extension Warehouse or the Sketchucation Plugin Store for ‘helix’, 'spiral" or ‘thread’. Or Google for ‘sketchup spirix plugin’ - the author has a separate website from which you can download it.
@DaveR has a few tutorials - I think on the Design, Click, Build website. Or maybe he will chip in with a reference.
I did do a tutorial on creating printable 3D threads for a blog post for Design. Click. Build. although I can’t grab the link at the moment. I’ll share it as soon as I have time to look it up.
