Spindle design

[Mean 69]

"The hard part of engineering something like this is determining the forces at play. It won't take much to be strong enough, but stiff enough takes more material in the right places. With the factory print, or part, you can reverse engineer it, to determine the loads it can take, and then design to the same loads, or a percentage higher."

This is largely true, but consider also that the factory pieces have somewhat different design and performance requirements, relative to a very high performance application. Further, today's street radials are better than probably all but the best race tires, and today's track tires are WAY better than those of even 20 years ago. So cornering forces go up well beyond what the factory was using as a design input, on the flip side the OEM's need to insure an appropriate safety factor - and cheap manufacture, so they usually go stronger than basic needs. But you are right, starting with a fundamental engineering analysis - free body diagram to understand all of the forces and moments in all driving conditions - is the very first part you should start with.

In general, 7075 is an excellent material choice for small production runs of such parts, as long as the part is designed correctly.

[Cdh84Z28]

If it would let me post a picture, there is a prototype cut already.