As a general rule I don't see a problem with that - do it all the time. A good example is a hole in a part starting with a sketch on the face of the part since that's where I want the hole to start.
You must consider the design intent before modeling, that's mean how the model should behave when it's changed.
Good morning John,
It can be good and bad, depending on the assembly and the possibilities of total make over changes. Not a good practice if you are designing a "New" never done before project, however if you are doing a re-design on a older assembly, than you will know what will possibly change and what won't.
For larger and new assemblies I use a Skeleton Sketch Part and base everything off that, which consists of planes, points and sketches.
All good, but it depends what your doing,
I like your response John (and others). When it comes down to it, it all depends on your design intent and how the modeler wants his model to behave under changes. A very broad question which I believe everyones right :-D. Thanks for your time. Have a nice week! Happy Monday!
I like others agree it depends on the design intent. I create sketches on feature surfaces, but it depends
on what, how that surface interfaces with possible other components in an assembly. I have gotten burned before doing this
when the said surface changed and possibly the mating surface in the assembly failed or errored.
But again this all comes down to design intent. I will say if it is a surface that you can see down the road is a standard
surface that might be a central point of contact in the assembly, then using a plane would probably be best.
Like Wayne, I do it all the time. Due to changes I occasionally have a sketch lose it's sketch plane or references, but it's usually no big deal to fix and I prefer that to creating a bunch of extra planes and reference sketches.
On the other hand, I'm a one-man-show here. If I was working on someone else's models, or vice versa, I might feel differently.
There is no real problem to doing this in a general sense. I think it's one of the workflow features of SolidWorks that makes it so easy to use. I've trained and worked with users who came over from other 3D CAD modelers and when I open their models there are unneeded planes everywhere. Makes it very difficult to work with a part like that. If you don't want to use model faces, then you will need to use 3DSketches or planes. Either way, you have a longer path to a finished part, but you will get there.
The biggest drawback I see is with novice users who put sketches on model faces that paint them into a corner down the road when they want to remove or modify that same face. Being careful about parent child relations and when they are created is a huge skill needed for more complex geometry so these things don't happen.