Twist Lock 30 amp 220 to Duplex Pigtail

Wiring a 4-prong 30 amp 220 twist lock pigtail adapter to two duplex receptacles using 10 gauge four conductor service cord. Tinned the wires on the plug side and soldered spades to the receptacle side. I am not an electrician and the method I show may not be acceptable to certain legal codes. Therefore I can't recommend producing this adapter without consultation from a professional. Use my method at your own risk for your application.