How do I Build a Trailer Winch?

How do I Build a Trailer Winch?
You need a method of getting boats or other heavy items up and onto the trailer's cradles. Winches accomplish this with mechanical assistance and gear and pulley ratios. You can set one up on your trailer to give you the needed strength to pull boats or heavy objects onto the trailer. Count on the project taking a day to complete.


Difficulty: Moderately Challenging

Things You’ll Need:
  • Metal spool - 6-inch diameter with gear bushings on the spool spindle
  • 85 feet of 3/8-inch steel cable
  • Trailer winch mount cradle
  • Deep cycle battery
  • DC motor
  • Red/positive and black/negative cables
  • Ground wire
  • Wire cutters
  • Power drill with metal bits
  • Metal screws with washers
  • Nuts, screws and washers
  • Locking steel carabiner or C-clip
  • Steel crimping fid - 3/8 inch
  • Crimpers
Step 1
Locate where you wish to attach the winch along the trailer arm. Mark the spot with a scratch on the metal. Position the winch cradle over this mark and scratch where you will drill the attachment screw holes into the trailer arm.
Step 2
Drill out the holes in the trailer arm with the power drill and metal bit. Use a 1/2-inch bit. Position the cradle over the holes and align so the screws will fit in both and then place a screw into both holes, and add a nut above and below each screw. Use a wrench to tighten and lock the cradle into position.
Step 3
Remove the spool rod out of the center of the spool and then place the spool into the cradle, aligning the side holes of the cradle with the spool rod holes. Push the spool rod through the cradle, spool and other spool holes. Attach the spool rod with nuts on either end to lock it onto the cradle. Attach the gear bushing to the spool spindle according the gear bushing ratios.
Step 4
Run the black/negative cable from the deep cycle battery, stored in the front of the trailer, to the black/negative connection on the DC motor. Run the red/positive cable from the battery to the DC motor. Attach the cables to the battery terminals, red going on red, and black going on black. Run the ground wire off the negative terminal of the battery and attach the other end to the metal of the trailer.
Step 5
Secure the DC motor to the gear bushings at the cradle. Screw the motor into position so it extends off the trailer arm running perpendicular to the arm.
Step 6
Thread on end of the 85 feet of 3/8-inch steel cable into the spool's cable entry hole. Turn the DC motor on so the spool begins to turn. Guide the cable onto the spool so it does not bunch up. When there is 1 to 2 feet remaining, turn the motor off. Attach the C-clip to the end of the cable line with a steel crimping fid. Place the crimpers over the fid and tamp it down so it secures the C-clip. Loop the C-clip over the cable into a double figure eight knot. Loop the steel locking carabiner into the loop off the knot.

Article Written By Eric Cedric

A former Alaskan of 20 years, Eric Cedric now resides in California. He's published in "Outside" and "Backpacker" and has written a book on life in small-town Alaska, "North by Southeast." Cedric was a professional mountain guide and backcountry expedition leader for 18 years. He worked in Russia, Iceland, Greece, Turkey and Belize. Cedric attended Syracuse University and is a private pilot.

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