Cable Actuator (telescoping Cylinder) and Winch

This is how to make a 20" travel telescoping cylinder that is cable operated via a winch. The goal was to make it light, strong, and cheap to build using 3/4" PVC. I use it to tilt a solar panel on my kayak. Adjusting the solar panel tilt provides more power for my trolling motor.

1 ea. Rigid Aluminum Tubing, 1-1/4" OD, 0.035" Wall Thickness, 3' Long, McMaster-Carr part 8978k233

1 ea. 3/4" PVC irrigation pipe, hardware store (sold in 10' lengths)

1 ea. Bicycle brake housing, 3 meters (Amazon)

2 ea. Stainless steel bicycle shift wire 2 meters long (often sold in a pack of 10, Amazon)

1 ea. HCS V625ZZ V groove wire guide pulley ball bearing 5x22x5mm (eBay)

1 box #4 x 1/2" pan head stainless steel sheet metal screws (hardware store)

1 ea. 1/4-20 stainless steel pan head screw 1-1/2" long (hardware store)

2 ea. 1/4-20 stainless steel pan head screw 1-3/4" long (hardware store)

1 ea. 1/4-20 stainless steel Nylock nut (hardware store)

1 ea. 10-32 stainless steel pan head screw 1/2" long (hardware store)

1 ea. 10-32 stainless steel Nylock nut (hardware store)

small amount of PLA filament for 3D printed parts

2 ea. 18ga. wire crimp terminal or bicycle adjustable wire nut

This actuator was built to tilt an overhead kayak solar panel / sunshade into the sun to gather more power for the electric trolling motor. The design goal was to tilt the solar panel frame quickly, which ruled out slow linear actuators; plus the linear actuators produce way too much force which could easily break the PVC frame if something got stuck. Thus, cable actuation was chosen, and a winch also designed so the actuation speed could be regulated via a hand crank.

The first part of the design was to place the frame in various tilted positions and see what the required extension of the 3/4" PVC pipe was relative to a fixed mounting point on the kayak. I chose to have about an 20" stroke, extending from a 22" long aluminum tube. I cut the PVC and aluminum tube to length. Be sure to cut the aluminum tube carefully so the tube doesn't get distorted- it has very thin walls.

The top of the aluminum tube has a 3D printed part that holds a V grove ball bearing pulley for the wire that pulls up on the bottom of the PVC pipe, allowing the wire to change direction. The cable housing stop for this wire also fits next to the pulley, and transfers the cable pull stress to the aluminum tube. Another cable stop is also fitted for the wire that moves the PVC back into the aluminum tube, tilting the opposite way in the process. The 3D top part also has a built in bushing to center the PVC pipe and has a cutout for the wire to fit through. At the bottom of the PVC pipe, another bushing is glued to the PVC also to center the pipe. The wire that attaches to the bottom of the PVC is just above the bushing so it doesn't interfere. .

Insert the 3D printed attachment part (plug) into the bottom of the tube and drill a 1/4" hole to match.

Test fit the 3D printed top part on the aluminum tube, mark and drill 3 holes for the #4 retaining screws and cut the screws to just fit inside the aluminum tube (can protrude a max. of 1 mm inside), de bur the holes. I used a nibbler tool to cut a gap in the tube for the wire (match the inside cutout in the 3D printed part). Attach the V grove pulley to the 3D printed part with the 10-32 nut and bolt.

Put the 3D top part over the PVC pipe by itself.

At the bottom of the PVC pipe drill an angled hole (so the wire lays flat against the PVC) about 1/2" from the bottom. Thread the wire shifter cable through the angled hole from the inside, the cable stop on the wire will secure it in the PVC pipe. Thread the wire through the top 3D printed part, around the pulley and through the cable housing hole. Glue the small 3D printed bushing to the bottom of the PVC pipe. Insert the PVC pipe into the aluminum tube. Attach the 3D printed top part to the aluminum tube with the 3 retaining screws.

Print the 3D parts, insert cable drum into housing, install crank handle over cable drum and secure with 1/4-20 x 1-3/4" screw. Install crank knob with 1/4-20 x 1-3/4" screw. Angle holes in cable drum so wires will lay flatter when wires are fitted. Sand if required, and lubricate with light oil.

Cut the 2 cable housings to 2-1/2 feet, ideally use a cable cutter (can use hacksaw and file ends flat). Drill a hole in the PVC pipe about 3" above the minimum actuator extension point (I drilled through a PVC pipe Tee instead). Thread the retract wire through the hole in the PVC, then through the 3D printed top part's retract cable stop, then through cable housing. Thread the actuator's extension wire from the pulley cable stop through the other cable housing. Test retraction and extension by pulling on the wires.

Determine which way you want to turn the crank to extend the actuator. Mine cranks clockwise to extend, so installed the extension wire and housing in the bottom cable guide of the winch housing. Then wrap one turn of cable around the cable drum when actuator is fully retracted, then through hole in the drum. Secure wire inside the drum with a cable stop, I used a electrical terminal crimped on via vise grips. Don't cut the excess cable yet, wait until the actuator works as expected; you can cut the crimp off if not positioned properly. Pull the actuator out, and install the retract wire, wrap one turn around the cable drum and insert through the other hole in the drum. You may need to remove the crank handle screw for better access when installing the cable stop (to better remove slack in the wires). I used an adjustable wire cable stop (has a set screw) to secure the retract wire. Test the winch. Install the winch housing on 3/4" PVC pipe and secure with one screw.

Done !