I know that Park Tool has their own crank removal tool but, WHAT IF you want to make your own??
Step 1: Materials & Tools
•1.375 inch x 1" Dia 6061 aluminum solid round
•.125 inch x .5 Dia 1045 mild steel solid round
•2 inch x 5/16 - 18 Grade 8 bolt
•Metal lathe (thread cutting ability)
•Round End mill - (5/8)