Quantity   Component name
2 × 600 p/r Rotary Encoders https://www.amazon.com/Signswise-Incremental-Encoder-Dc5-24v-Voltage/dp/B00UTIFCVA
1 × Arduino
1 × 550 RPM Gear Motor https://www.amazon.com/gp/product/B01KTZXZDE/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
1 × LARGE Paint Stirrer Rod Get a good one. You're worth it.
1 × 3D printer For various parts
1 × GT2 Belt
1 × Motor Driver Ours is way overkill from a previous project.