Can't subtract derived part but don't know why

angel_hernandez326

I keep running into errors similar to this and I never seem to figure out how to solve it properly… I always end up working around this kind of issue, so I hope I can learn from someone more knowledgeable here :)

Here is a link to my document: https://cad.onshape.com/documents/d1da93a1497d672f4bd5d0c2/w/3f1bdf132bebb70841bf45eb/e/fe452418000da36dc9af8584?renderMode=0&uiState=67c49451f242694bd8392cc5

I have two parts I'm trying to subtract; I named them TARGET and TOOL.

All I want to do is subtract them with an offset on all sides just so I can print TARGET with a hole that's about 0.2mm bigger than TOOL, but I keep running into an error without much info in it regardless of the offset distance and direction:

Can anyone tell me what I'm missing here?

Thank you!

GregBrown

When you are trying to "Offset all", you are automatically including a LOT of faces that really have no impact on the cutout, except of course to mess it up. If you just do the Boolean subtract with no offset, this is what you get:

Note how those copper traces from the PCB are imprinted too. Those pockets have a depth of 0.035mm….
It would be better to a) simplify the PCB to remove those faces before doing the Boolean subtract without offset, then b) offset the faces in the cutout


Alternatively if you don't want to mess with the PCB, you could a) do the Boolean without the offset, b) remove the faces of the pockets left by the PCB trace (see image below), then c) do the offset of 0.2mm

angel_hernandez326

Ah! That makes a lot of sense!

I will try to simplify the board since that antenna is just printed and most times doesn't even have any depth.

Thank you so much for pointing this out!