Small horizontal (bolt down) winch with 3:1 gear ratio.

Print settings (Orca Slicer 3mf included)

• 0.2mm layer height

• 5 perimeters for casing, spool, driving gear, both axles

• 3 perimeters for lever, shaft caps, handle and crank

• 20% or more infill

• For more stability use alternate extra wall

• Use snug support for the bearing holes and the spool (slicer file with painted support is available)

• I printed all parts in PLA

Assembly steps

Needed hardware

• 4 x 608 bearings

• 8 x M3 threaded inserts + 1 if used for set screw in crank

• 8 x M3 x 6mm bolts (axle/shaft caps)

• 1 x M4/M3 bolt (depending whether threaded insert is used for the crank)

• 1 x M4 x 20mm bolt and corresponding nut (lever)

• small spring, e.g, from a ball pen for the lever

Step 0: Test for tolerances

No matter the precision of CAD, every printer has its own mind when it comes to tolerances and precision. The best way to ensure a proper fit for the bearings is to use the STEP files (or onshape design), test print a cutout and adjust the tolerances to fit your printer.

Step 1: Cleaning and checking the prints

After printing all parts remove the supports and make sure that the holes for the axles in the casing are correct in diameter. Drill out or file to 8mm if necessary.

Step 2: Threaded heat-set inserts and bearings

Use your preferred method to melt the threaded inserts into the casing (and the crank if you use one there).
The bearings should sit snug in the casing and spool. Sand or file if they are too small. If they are too big it is possible to shim the bearings with tape or paper, but it's better to test prints for tolerances first (Step 0).

Step 3: The locking lever

Test fit the M4 bolt for the locking lever. If the hole in the casing or lever is too small drill out to proper dimension. Glue the nut into the hexagonal hole. Install the lever and use a small spring to keep the lever under tension. I didn't have a sacrificial ball pen at hand, so I quickly wound up a small torsion spring. For the spring of a ball pen, drill out the holes in the lever and casing to fit.

Step 4: The drive gear, axle and crank and handle

Test fit the axle with the bearings already inserted into the casing. It should fit well already. Now comes the part that was the most work for me: test the fit of the drive gear. Try to slide the drive gear over the axle. It should have a tight fit, but without much friction. For me the axle came out of the printer with a bit of distortion (print the axles slow for best results). So I gradually filed down the axle until I was able to slide the gear on without much friction. As soon as this point is reached, we can start assembling the drive gear axle.

Insert the axle from one side and slide on the drive gear. Add the locking block and two washers as on the photo. Then finish the assemble by fitting the axle through the other hole. The drive gear should be right at the wall to the casing with the two washers keeping it in a safe distance. Install the blind and handle caps with the M3 bolts.

Glue the handle to the crank and use an M4 bolt as a set screw (or M3 bolt + threaded insert). When the glue is dry, slide the crank-handle arm on the drive gear axle and lightly tighten the set screw.

Step 5: The spool

Insert the bearings into the spool and bring it into position in the casing. Use more washers, one on each side to keep the spool centered. I used a little silicon grease to stick them in place on the bearings. Insert the spool axle and install the remaining two blind caps.

Work in progress, things to improve:

1. I'm not happy with the spring solution for the locking lever. I might modify it to use a rubber band instead.

2. The hole for passing through a rope in the spool goes through the center. The path is then blocked by the spool axle. I'm considering offsetting the hole so that doesn't happen.

3. The handle and crank are glued together at the moment. There might be a better solution for this part.

4. The bearings fit relies on tight tolerances. For me they fit perfectly at the first print but it might be better to add little protrusions to lock them in place. This mostly concerns the bearings inserted into the spool.

5. You can use an additional threaded insert to mount the crank on the driving gear axle. I figured a M4 bolt just worked fine as a set screw.

Safety

Do not overload. I only tested it with about 1kg of load.

CAD files

All files are available as STEP files. Remixes, additions and modifications are welcome :) The Onshape design is here.