Gal, writing at Mare & Gal Electronics, documented an electric drum winch built to tow a wakeboarder. The 12 kW motor and the 24S10P battery pack, about 100 V charged, were pulled from a scrapped Awake board. The frame, drum, belt drive, rope guide, electronics and firmware are all his own work.

The drum core is 200 mm across and 120 mm wide, 3D printed, with 6 mm laser-cut aluminum flanges. An HTD 5M belt gives a 7.1:1 reduction, good for roughly 39 km/h rope speed and about 1170 N of pull. The rope is 300 m of 3 mm Dyneema SK-75 at 0.87 EUR per meter, the single biggest cost in the build.

With 13 to 17 layers of rope on the drum, a level wind was needed, so the winch has a motorized rope guide on an SFU1204 ball screw driven by a NEMA 23 stepper. A custom 4-layer board steps the 100 V pack down to 48 V and reads the VESC tachometer over CAN at 250 kbit/s. One drum turn moves the carriage 3 mm. Total cost was about 700 EUR.

See more at e.pavlin.si.