What Should Surfacing Be Used For?
Surface features are one of those things that 90% of Solidworks users will never have a need for. If you’re doing machine design or sheet metal or a lot of basic work that’s out there, you really may never have the need.
But there are times when you really do need these tools.
- Import repair
- Mold work
- Complex and organic shapes
Surfacing can be used in addition to solid modeling, and the goal of surfacing is almost always to make a solid model in the end.
With solid modeling, you make all the faces of a feature at one time, and there should be enough faces to fully enclose a watertight volume.
With surfacing, you’re generally working with a single face at a time. You’re either working toward a watertight volume solid, or modifying a solid.
Does This Need Surfacing?
Radio Case
Probably not, but maybe. I know that has a really definitive sound to it. If it’s really as boxy as it looks, then no. If there are some subtle curves in there, then yes, or at least maybe.
I looked through the feature manager for the parts in this assembly, and there were no surface features in it at all.
Rifle Stock
Probably. You could do it without surfaces, but it might be awkward and maybe “non-optimal” as they say. In my model, 80% of the features are surface features.
Remember that with surfacing, you generally have to make each face as a separate feature. If you’re making a block, that’s 6 times as much work to use surface features compared to solid features.
Also, please don’t fall into the trap thinking that fillet features are for sculpting or making shapes. They aren’t. Fillets are just for breaking edges. You don’t make parts round with fillets. Or shouldn’t, let’s say. Some people try.
Law Enforcement Device
No. Again, this is an assembly that is mostly plastic, but there’s only one cam ramp, and even it didn’t use any surface features.
I’m not talking about what is geometrically most efficient, I’m just talking about how these particular models were actually made. Remember that surfacing takes at least 6 times as many features and time as normal solid features, even though the computer has to do a lot more work for solids, the computer does that work much faster than you do.
Aero flow Device
This part could go either way. It could have been done fully in surfaces, or in this case, there was only a single surface feature in the whole part.
The mold to make this part would have been a different story. The parting line is what is complex here. It is internal, and it jumps all over the place with passing shut offs and probably minimal draft.
This looks like a complex device, and it sort of was. I worked with the faces colored for direction of pull/draft from the mold. Even with all of the crazy shapes going on here, this only had a single surface feature which could have been avoided, but using it made things easier.
Pickup Truck Cap
As simple as it looks, this was done mostly with surfaces. It probably could be done with straight solids, but it would have been ugly. There is some subtle curvature on each face, and the best approach was really with surfaces.
This was done a long time ago, and there have been some functions added to the software in the meantime that would have made parts of this, especially the windows, easier to create.
Avionics Panel
I’m not sure I ever knew what this was, but it started as an imported part completely out of context, and then had to be modified using surfaces to add curvature and various features. It was probably a plastic or die cast part.
Shampoo Bottle
This bottle started from a 3D scan, and then was surfaced over that. It was 3/4 surfacing features, and 1/4 solids. The solids were mostly the mechanical details. Fillet features can be applied to either solid or surface bodies.
Looking at this after 14 years, I can see some things I would have liked to have done better. I remember this was done between several other projects in a rush, and I think in the end it was a test.
Forged Handle
This was a handle part that came up in a training class a few years ago (~17). It was 100% surfaces. A student brought a physical part with them to class and on the spot asked me to model it. There are no truly flat faces, and all the sketches were splines.
Musical Instrument Stand
This was a small assembly of plastic parts and forged or die cast parts. It was meant to sit on the floor and you’d put your flugelhorn or trumpet on it, and the device would just hold your instrument. But it also had to fold down small and store in the bell of the instrument.
In this case, the plastic parts were 100% solid, and the die cast leg was 80% surfacing.
The project just came to me randomly, but as I’m a brass musician myself, this was particularly interesting to me. Unfortunately they didn’t want a trombone stand designed, which is my instrument.
Photographic Equipment
This was a piece of photographic equipment that was going to be cast in aluminum and then machined. The first few features were surfaces, and then the remaining 90% were solid.
Many of these models were reverse engineered from an actual part with some changes or modeled from hand drawings/napkin sketches.
Soap Dispensing Penguin
What would we do without a little whimsy? Believe it or not, the plastic parts of the housing are about 50% surface features. Even some of the internal parts used surface features, although I’m not entirely sure that was necessary.
Looking at this, there is a lot of detail missing here. I’m not sure that this was ever a real project that I fully took on. I think I was just involved in creating or adjusting an internal mechanism for this design once the original was found not to work. I didn’t do the original work.
I’ve done a lot of projects and I’ve probably forgotten most of the ones that weren’t major jobs
Summary
So you can see with a wide range of products, some use surfacing and some don’t. Should you learn how to use surfacing? How limited do you want to be? I can’t say that this is a fair representation of all the products you can make in CAD, but it is a fair slice of things I have worked on.