Need subtract and add functions that work

Help somebody!!! What is the best extension for Add and subtracting? My Sketchup subtract and add functions aren’t working properly. It’s very inconsistent . Unless there is a reason why it only works periodically, I need to find a good, reliable extension recommended by someone who’s gone through something similar (I’m lucky if it works 1 out 6 tries) even then, I may only get half of a solid model done and it becomes very nerve racking when it doesn’t work.

Probably what you really need is an appropriate workflow for the sort of objects you are modeling. The Solid Tools are predictable and dependable if the models are made correctly. There are a couple of extensions that also do Boolean operations but they won’t work any better if your model isn’t right to begin with.

Share a model file so we can see what you are working with.

BoolTools and Eneroth Solid tools are a couple of extensions for Boolean operations, but they use the sama algorithms as the native tools and differ only in their output (preserving components etc.)

I wonder if the perceived inconsistency is due to SketchUp’s inability to handle endpoints that are very close to each other (e.g., very short edges)? Perhaps the failures are the result of SketchUp merging such closely-spaced endpoints (which can easily occur along the boundary between curved surfaces). The “Dave” method of editing a scaled-up component is very effective at overcoming this SketchUp behavior.

The only cases I’ve encountered where the solid tools (I prefer BoolTools2) don’t work are due to very strange geometry in the solids. But well over 99% of the time there is no issue. So, I agree with @DaveR that if you can share an example and point out where you get odd results that would help to understand what is happening.