How prevent LOTS of unwanted geometry in extrusion?

[lens42]

Lets say I have a component like this:

Then I place a sketch on the top surface, and extrude a 2nd component on top:

My problem is I don't want any of the holes from the bottom component to be in the top component. I just want a solid on top. I know I can click on all the holes and extrude them with the top solid, but what if there are LOTS of holes? This is just simple illustration, my REAL problem is that I import an Eagle PCB for the bottom component, with 100s of tiny holes of different sizes. If place a sketch on that and extrude, the number of holes is overwhelming. Is there a better way?

[leowarren34]

Hi @lens42,

Create an offset plane on the side you want to extrude with an offset of 0.00mm,

Sketch on the offset plane the profile you want to extrude.

Extrude profile - easy!

I'm happy to provide a screencast if that fails to explain.

[g-andresen]

Hi,

try this:

günther

[HughesTooling · Accepted solution]

Turn off all auto projection, then when you create the sketch on a face it will not contain all of the edges from that face. Turning off auto projection does mean you'll need to manually project curves you need but you will end up with cleaner more efficient sketches.

Mark

[lens42]

Wow! Three quite good solutions. Thank you, hive mind.