Confused about combine behaviour

[Anonymous]

The screen cast below shows what's going on. Cutting one body with another works, but when I delete extraneous body (created due to a hole in the tool body) the hole created by the cut fills in.

I'm baffled.

Worked around it by creating a sketch that intersects the spline and using push/pull to cut with that. It's actually a better solution as I need to **** the tips of the female spline points and I could do that on the intersection sketch.

I'd still like to know what's up with the hole filling back in.

The design is here: http://a360.co/29DCfdG

[Anonymous]

Ok, I remembered that there was some trick to this operation as soon as I posted. And sure enough, there is an option to "remove" the extra body created by the combine operation. You need to choose remove instead of delete.

I'm leaving this post up in case others run in to this same oddity. It's the second time I've tripped over it. Eventually it will sink in and I'll LEARN it.

So - why two operations that appear to do about the same (but clearly don't). Why does deleting the body null the combine operation where as remove gets rid of the cruft body left over?

If it's confused me twice, perhaps what's happening could be clearer? maybe a prompt that says "did you mean to use remove?"

I'm still learning CAD - so maybe it's just a concept issue for me.

[weshowe]

Because (puffs chest out) Fusion 360 is a "parametric" modelling tool (wheezes out last breath).

Seriously, what you are making by retaining the tool parts is different from what you made by removing them.

Both are a cutout (or joined) entity. But when you retain the tools (keep tools), the size of the cutout is linked to the other part. When you don't, the modification is permanent.

I'm not sure what practical purpose retaining that link has (maybe someone else does), but when you delete the other part the resulting cutout cannot stay because one of the equation inputs is now missing.

Anyway, I am also self-taught. My best friend is Ctrl-Z.

 - Wes

[TrippyLighting]

In this thread Jeff Ttrater has provided an excellnt explanation what the differece is between Remove and Delete.

Also, not keeping the tools does not mean that you loose the parametric nature of the tool.

Tools are features earlier in the timeline (before the combine operation). If you edit these features, the results of the combine operation will update.

Keeping the tools has more to do with the fact that sometimes you need to keep a tool for another combine operation with another body.