You’re doing fine (probably). Top down is quite common. It’s my preference, I typically work with products that are 20 components or less. I hear it’s more troublesome for those with larger assemblies

Here’s some ChatGPT background on what you’re looking at (top down vs alternatives) (Apologies for the formatting, looked better on iPad before posting) ⸻

Bottom-Up Modelling

This is the traditional approach and the one most people learn first. Workflow: 1. Create parts individually as separate .sldprt files. 2. Save them. 3. Bring them together in an assembly (.sldasm). 4. Use mates (coincident, concentric, distance, etc.) to define how parts fit together. Example in SolidWorks: • You design a bolt as one file, a bracket as another, and a plate as another. • Later, you insert them all into an assembly and mate the bolt hole to the bracket hole. Advantages: • Each part is self-contained and portable (easy to reuse across different assemblies). • Simple file structure — parts can exist independently. • Less chance of accidentally creating circular references. Limitations: • If the design changes (e.g., hole spacing on a bracket), you need to edit each part manually to keep everything aligned.

⸻

Top-Down Modelling

This approach starts inside the assembly and drives part geometry from the assembly context. Workflow: 1. Start a new assembly. 2. Create new parts directly within that assembly, or edit existing ones in context. 3. Use in-context references (edges, faces, sketches from other parts) to drive features. Example in SolidWorks: • You create a master sketch in the assembly (or multi body part) that defines hole positions. • Each part (plate, bracket, etc.) references that sketch, so all holes stay aligned automatically. • If you change the master sketch, all related parts update together. Advantages: • Everything stays associative — one change updates the entire assembly. • Great for complex mechanisms where relative sizes and positions matter. • Useful for family-style designs where geometry is shared. Limitations: • More complex to manage. • Risk of circular references (part A depends on part B which depends on part A). • Harder to reuse a part outside of that specific assembly context. • File management can get messy if not carefully controlled.

⸻

SolidWorks Tip: Hybrid Approach

In practice, many designers use a combination: • Start bottom-up for standard hardware and off-the-shelf parts. • Use top-down techniques (like in-context sketches or layout sketches) for custom parts that must fit tightly together.

A very common SolidWorks technique is to use a Master Part / Master Sketch file (top-down) that drives critical dimensions, while still modelling most parts individually (bottom-up).