How to punch holes in existing extrusion

ruth_ivimey_cook

In Onshape I have a model that has some 'pads' (electrical terminals) lying on top of a PCB (board), and these pads should have holes in them. The sketch for the pads doesn't have the holes, because another sketch, for the PCB body, has them (& also defines the edge of the PCB). It was easy to get holes in the PCB body (I just didn't extrude some faces, but not quite sure why that worked). Conversely, the sketch for the PCB doesn't have the pad shapes because the pads are on top, not through.

The sketch for the holes, and the sketch for the pads, have differing offsets, but are parallel to each other (1.5mm gap), because it is the extrude distance of the holes that forms the plane of the pads.

How can I make the holes in the pads?

I have tried using the Boolean tool, but I cannot make it work because it won't accept either a sketch or an extrude as input. I have tried several combinations of extrude operation (subtract seems useful) but cannot find one that works. Some combinations get the pads right, but obliterate everything else in the model :sa My model is public: https://cad.onshape.com/documents/a5c2a279e49528c89c09d0b2/w/dc89a9141b1c67c5842bdca1/e/54061859f71e3093f5c71781

wayne_sauder

@ruth_ivimey_cook
Here is the way I did it. Does this get what you want?  
https://cad.onshape.com/documents/421a6ec8a520b6097e7cb14b/w/5bb235e7e24a17c90aaac5fb/e/de8fe88ffc444bc015710796

ruth_ivimey_cook

Thanks for the video... very helpful.

I've fixed my own copy now, and discovered some errors in the original sketch and fixed them too! Yay!

wayne_sauder

@ruth_ivimey_cook  
Is this what you are looking for? 
https://cad.onshape.com/documents/421a6ec8a520b6097e7cb14b/w/5bb235e7e24a17c90aaac5fb/e/de8fe88ffc444bc015710796

wayne_sauder

@ruth_ivimey_cook
I simply used a extrude remove for this, but you could also use the hole tool and have the complete info available on a drawing level. If you want the part circle on the edge of the PCB then you will have to use extrude. There may be other ways of doing this as well but these are some ways I would do it.   

ruth_ivimey_cook

Hi Wayne, Many thanks for your help!

Almost right... the circular holes are ok, but there are also supposed to be 'cups'/segments taken out at the board edge, to match the board itself. (This style of board is known as 'Castellated').

Can you guide me on how to use extrude in this case -- as I said, I tried RTFM but I couldn't get it working. I suspect there is a step I missed somewhere.

I was trying things like:

1. Select the PCB part and also the Holes part.

2. Select Boolean Ops.

3. Note that in the dialog it hadn't included the two Parts; try selecting them & fail.

[Also tried that, but using the appropriate Sketches. Also Fail.]

1. Edit the Pads part

2. Select the Subtract tab, but cannot see anywhere to set the 'what to subtract'.

wayne_sauder

@ruth_ivimey_cook
Here is the way I did it. Does this get what you want?  
https://cad.onshape.com/documents/421a6ec8a520b6097e7cb14b/w/5bb235e7e24a17c90aaac5fb/e/de8fe88ffc444bc015710796

ruth_ivimey_cook

Thanks for the video... very helpful.

I've fixed my own copy now, and discovered some errors in the original sketch and fixed them too! Yay!