I have a component to rotate, but I want one point to always stay where it is. Is there a way to constrain or fix that point so that no matter what happens, that point stays in place? Something like a closet door handle where the pin has to stay in place, or fan blades where everything connected to the hub stays in place, etc.
A DC (dynamic component) with its local origin fixed in SketchUp’s main axes system should do.
Do you hahe SketchUp Make or Pro?
Just the free one. Can I do it in that or do I have to get Pro?
The first 30 days of Make (trial of all the pro features) should allow you to experiment.
If you’re already past these 30 days you could search for any DC with only X,Y and Z fixed.
You can’t alter the DC properties but you can still change (=replace) its geometry in editing context.
Thus creating your own component.
edit: since you may not know the pinned position X,Y & Z beforehand, such a component would most likely not meet your requirements.
I would be making my own component. I can only do that in pro, right?
That’s right. And as long as Pro trial works you’ll be able to edit the X, Y and Z values the component is constrained to.
Add a guide point - or even a line perpendicular to the rotation plane. The Rotate tool will stick to those. The guide point/line can be deleted/hidden/or placed on a separate layer that can have its visibility toggle off.
Look at the wag the tail example on this page.