[mplanchard]

In SolidWorks, create two configurations of the spur gear
1. Just pitch diameter (simplified)
3. With teeth if needed for visualization

If you what to test gear ratios in the assembly, use a Gear Mate with the simplified version, enter the ratio.

To see how a spur gear is created, in a new assembly insert a gear from Toolbox, then enter in pitch, teeth, pressure angle and all the other parameters. When you are learning - just take default on everything and then see what varies.

You can create the profile of a spur gear tooth based on sine and cosine functions - but this is really overkill and will bog down any large assembly in robot design.