Stepper Capstan Winches

The chief actuation system for the course projects is a four-axis stepper-motor driven capstan winch set. The primary construction material is laser-cut 6mm plywood. The enclosure houses four NEMA17 stepper motors and an Arduino with CNC shield and four A4988 drivers. An external 12VDC power supply is required for the motors, and a USB cable from the Arduino to a host computer.

Download the SolidWorks CAD files.

All designs and documentation available under a Creative Commons Attribution-ShareAlike License (CC BY-SA 4.0) .

Contents

• Stepper Capstan Winches

  • Renderings

  • Components

Renderings

Four-axis capstan winch set.

Laser-cut part outlines. All are 6 mm plywood except the power connector plate. Not shown: optional rear cover. PDF of outlines.

Capstan hub fabricated using 3D printing. This mounts on a Pololu hub to connect to the stepper motor shaft.

Rear view, showing location of steppers and Arduino.

Oblique view showing bottom. The cutouts are for adjusting the eyebolts which route the lines.

Front view. The letters are marked with a partial-power cut.

Rear view.

Side view. The Arduino USB connector is exposed via a cutout. A barrel plug connector is installed on a small panel behind the power cutout.

Top view.

Components

A partial parts list follows.

Size	Description	Vendor	Vendor Ordering
5mm x M3	mounting hub for 5 mm shaft, M3 holes on 12.7 mm circle, for stepper motors, includes 1.5 mm hex key for set screw	Pololu	1998
NEMA17	stepper motor, 76 oz-in (5.5 Kg-cm), 1.5 Amp/phase, M3 mounting holes, 5mm shaft	Automation Technology	KL17H248-15-4A
M3 x 10	socket head cap screw, 2.5 mm hex socket	McMaster-Carr	91290A115
M3 x 14	socket head cap screw, 2.5 mm hex socket	McMaster-Carr	91290A119
M3 x 18	socket head cap screw, 2.5 mm hex socket	McMaster-Carr	91290A121
M3	nut, 2.3 mm thick, 5.5 mm wide	McMaster-Carr	91828A211
8-32	Routing Eyebolt with Nut, 8-32 Thread	McMaster-Carr	9489T112
8-32	nut, zinc-plated, 1/4” width, 3/32” height	McMaster-Carr	90760A009