Two Turntables... and a Microcontroller - Part 1

My father is into HO railroading.  He's got quite the layout in-progress in his garage.  However, he's having trouble finding DCC turn-tables for his engine-yards.  The ones he can find are expensive and back-ordered.  My brother and I decided it would be a fun project for an Arduino (or three).  Here's the first installment of build pics and videos.

Materials:

• 1 Arduino Duemilanove
• 1 Adafruit Motor Shield
• 1 Stepper Motor (PF35T-48)
• 1 2-pack of 3x86mm Shock Shaft (HPI Racing 86055)
• 1 4'x8' sheet of 1/4" plywood
• 1 8' plank 1x4"
• 1 box #6x3/4" machine screws
• 2 railroad wheel truck assemblies.
• 2 screws of unknown variety from my parts pile. (for affixing the trucks to the bridge)
• 2 plastic bushings (used as stand-offs for the trucks)
• 2 RRP-1028 48P Pinion 28T
• 2 #6 5/8" screws (for affixing the motor)
• Wood glue (for making pylons for the motor mount from a double-thickness of 1x4)