Rack and Pinion Design 1 - spur gear design in solidworks

How to design a working steering rack, rack and gear or rack and pinion mechanism, understand how the pitch circle drives other factors. Identify which characteristics control the gear design and why the module, number of gear teeth and pressure angle are important. The relationship between addendum, base diameter, pitch diameter, clearance diameter and root diameter is also discussed.

This video gives a practical demonstration on how to detail the spur gear, involute curve, gear tooth profile, pitch circle, circular pitch, dedendum, addendum, whole depth, addendum circle, clearance circle, root circle, base circle, pressure angle and how it relates to rack design.

[tinchan]

took me a week to find a right video whose actually use the equation and drawing techniques right. thank you

[EricLaspe]

Thank you for this helpful video. I followed along with your process in Fusion 360 and found that each step could be followed more or less exactly with Fusion's very similar tools.
I did run into a problem, however, when I tried to change the variables after creating the gear. Some small changes that should have worked destroyed the tooth geometry. I discovered that the fit point spline has handles for each point we linked to create the involute curve, and if those handles are unconstrained, wacky things will happen when parameters get redefined. So I'm now going through the process of figuring out just how to constrain each handle. I believe the handles should be perpendicular to the tangent lines that intersect them, so adding tangent constraints is my first move. I also think the length of each handle should be proportional to the length of the tangent line (i.e., it will be some multiple I haven't discovered as yet). I'll come back and leave another comment if I figure it out.