Better way to cut out a shape along two dimensions?

creyc

Sorry the title's not great, it's easier to describe what I'm trying to do in pictures:


I'm struggling to create this sort of indentation cutout along the edge of a case, which means it has both a top and a front profile. I did this in a very hacky way with two parallel chamfers just to illustrate the final result, but is there a better way to do this?

https://cad.onshape.com/documents/57657c18e4b0887c5137f2c4/w/7f77bdc59988a60068a84fa5/e/e99302cf4a7d11cd0d67ec4d

Ultimately I'd like to have more control over the profile shape than what I can do with just a simple chamfer.

anthony_serna

creyc said:

I attempted to do this with a loft early on, as ideally I'd like to use a slightly different shape from top to bottom.  However I couldn't think of a way to achieve what I wanted using a loft, as the loft documentation seems to say I can't loft nested countours (like rings).

Do I need to create two lofts, ADDing a larger one with my part and then REMOVING a slightly smaller loft?  Or is there a way to do this in one step?

Thanks!

You should be able to loft nested sketches...I did this, meaning you can have more than a few different sketches in the same sketch, to loft you still need two sketches of course.

I did you what you were asking with two sketches, a plane for offset (dont like using faces much), loft, and an extrude.

here is what mine looks like (from your file):

mahir

There are lots of ways to control geometry in CAD. In this case, you could use a Loft, Sweep, or Extrude with draft. Which one is the best option just depends on what your end goal is.

creyc

I attempted to do this with a loft early on, as ideally I'd like to use a slightly different shape from top to bottom.  However I couldn't think of a way to achieve what I wanted using a loft, as the loft documentation seems to say I can't loft nested countours (like rings).

Do I need to create two lofts, ADDing a larger one with my part and then REMOVING a slightly smaller loft?  Or is there a way to do this in one step?

Thanks!

owen_sparks

creyc said ...as the loft documentation seems to say I can't loft nested countours (like rings).

Thanks!

But it will allow separate sketches placed on top of each other.

My first instinct would be to loft a drafted solid and then shell it.

Owen S.

anthony_serna

creyc said:

I attempted to do this with a loft early on, as ideally I'd like to use a slightly different shape from top to bottom.  However I couldn't think of a way to achieve what I wanted using a loft, as the loft documentation seems to say I can't loft nested countours (like rings).

Do I need to create two lofts, ADDing a larger one with my part and then REMOVING a slightly smaller loft?  Or is there a way to do this in one step?

Thanks!

You should be able to loft nested sketches...I did this, meaning you can have more than a few different sketches in the same sketch, to loft you still need two sketches of course.

I did you what you were asking with two sketches, a plane for offset (dont like using faces much), loft, and an extrude.

here is what mine looks like (from your file):

mahir

Another suggestion - don't box yourself into creating all your geometry in one shot. This tends to create complicated sketches that are difficult to modify down the road. Case in point, while lofting doesn't allow nested sketches, there's nothing forcing you to create all your geometry with one loft. Often, a combination of features will yield the most flexible and robust design. It's all about the design intent.

NeilCooke

I still think extrude with draft (or more likely, extrude then draft) is the best option.

creyc

Thanks so much everyone, the screenshot helped quite a bit, anthony_serna.

I was able to do this quite well with a loft add to create the outer wall, followed by a loft remove to cut out the inside.