DISQUS

Rod_Uding · 3 months ago

Great post Josh. Although I have never had to do this type of feature, it is always interesting to read about it and bookmark it just in case. Adding this one to Google Reader for sure.

ecirwin · 3 months ago

If you have solids, how about just extruding a cut up to an offset surface. You can do that with 1 feature, because you can offset the surface within the extruded cut. That is about as easy as it gets. I think that the surface has to be all one patch, but that seems to be what your example is showing.

Josh M · 3 months ago

AWESOME ecirwin. This is a great method too. It rebuilds a lot faster. Twice as fast as the last method. The only problems I've had are with getting a draft and the cut is always straight into the surface. Still, this is a super good method for very shallow recessed features. Thanks!

ecirwin · 3 months ago

I would say that unless you are making this feature more than 1mm (.040") deep, the draft is overkill. If you really need the draft, I don't see why a Parting Line draft wouldn't do the trick. We use this method all the time to put text on our parts.

Josh M · 3 months ago

It probably depends on the part and the manufacturer. I've been recommended draft from manufacturer. It's probably more of a catch-all, just-in-case type thing though - a general rule for the parts they mold.

While the draft probably isn't needed in most cases for shallow cuts like this, having the option would still be kinda nice.

ecirwin · 3 months ago

Josh,

Are you saying that you are unable to apply the draft at all? A "Parting Line" draft isn't working? Or is it that you have to add another feature to get the draft, and you just don't like that?

Eric

Josh M · 3 months ago

Hey Eric, I don't mind the extra feature so much if it works. Like in the second option. I couldn't get a draft on that one unless I convert the profile to sketch lines in 3D sketch, then add a cut with a draft, like in the 3rd option.

Still, I'm hoping this will be a single feature in the next release.

Petr · 3 months ago

Another thing you can do is to make the cut-extrude "from surface." That way, you don't have to worry about offsetting surfaces to extrude to. However, this method doesn't let you add draft.

(Also, hi everyone! I've been reading this site for a while, but this is my first post here. I hope to join in more discussions in the future. Thanks!)

ecirwin · 3 months ago

My method does not require you to create an offset surface. From within the Cut feature for the depth choose Offset from Surface.

I never create draft from within a Protrusion/Cut. It generally just leads to problems and the inability to find the draft to change it when I need to. Maybe it is old school CAD, but I try to create all my features, then create draft, then create rounds. Seems to create robust models most of the time.

Josh M · 3 months ago

Hi Petr, thanks for the comment. looking forward to getting your input in the future too. That method definitely save on rebuild time.

Kieran Choy · 3 months ago

For a sloped recess - offset a surface, then use a body copy/rotate and rotate the offset surface a small amount, then trim, loft and knit. Not sure about rebuild times, but you could always use trim with multiple contours in a sketch instead of split lining it?

Also, not sure about how well the rotate method for creating a sloped recess would work on surfaces with a high degree of curvature - my guess is you would need to copy the initial sketches and modify the geometry in these cases.

Josh M · 3 months ago

Hi Kieran, I love it. that sounds like a great method. I haven't tried this yet, but I have a model coming up that I'll need to do this on. Your suggestion will be the first one I try :) thanks!

Kieran Choy · 3 months ago

Haha, I've never actually had to model this, so I'd definitely like to know how you get on.

Charles Culp · 3 months ago

The difference between Extrude To Surface (or extruded cut to surface), and an offset is a matter of the sides, and the curvature. Extrudes will create flat sides, and a linear extrusion. If you are looking ad embossing or debossing a logo into a plastic part, then it is definitely the way to go. You can then create draft, and it will be easy to make.

The reason to consider an offset surface is for more complex shapes. If you want it to cover a 90° bend, for example, it will have to be an offset, because you cannot extrude in both of the directions. Because the "curvy surface" used in this example is almost flat, this is not noticeable.

Also, if it is a plastic injection molded part, with the offset surface you will have to accommodate the draft with other solutions. Simply "applying draft" will probably not work, and that will all just depend on the model.

Josh M · 3 months ago

For those that are curious, I've updated the post with a method from Mark Biasotti of SolidWorks. It takes a little bit longer to rebuild, but it creates a draft recess with a couple features.

Leonard · 3 months ago

cool! never heard of Solid Works until now! 3d program?