• ​UNI-T UT136B Multimeters ($16.56 each)
• ​JDS2023 Handheld oscilloscope ($113 + battery)
• ​Eagle CAD Schematic/Layout ($0)
• ​Ferrule Crimper Ferrule Crimper, to eliminate problems caused by stray wire strands ($23.99)
• ​20 AWG Ferrules 20 AWG Ferrules, as above. $3.99/20 pcs
• ​18 AWG Ferrules 18 AWG Ferrules, as above, $3.99/20 pcs
• ​PWM Crimper Crimper for building PWM cables, Micro-Fit Encoder cables, etc ($39.95)
• ​Desoldering Tool Weller desoldering tool. $25.60 ($6 shipped from ​amazon and $2-5 from ​banggood)
• ​12V/7AH batteries for Peanut Bots $14.90 Cheapest price I've found (​amazon has 'em too)