Plastic Square Tube Caps for Bike Trailer Hitch

thingiverse

This is a series of custom-designed plastic tube-caps with precision-cut holes for securing a steel trailer hitch on a bike. The plan involves fabricating a seat-post mounting hitch, similar to the one shown in the photo, and then printing these caps to fit snugly into the 1.5 x 1.5 x .065 inch wall square tube section. Next, slide it over your seat post to pull a reliable bike trailer or trail-a-bike - in this case, the hitch was tailored for a Trek Mountain Tram. The caps are specifically engineered for use with 1.5 x 1.5 x .065 inch wall square tube. I've included detailed SolidWorks files and Parasolid models if you'd like to modify them to fit different sizes - for my purposes, this design worked perfectly because it left sufficient space between the seat tube on a 31.9 mm seat post and the tube wall without requiring a larger square tube size. I've incorporated three distinct hole diameters: 28, 32, and 33mm, as these were the specific sizes I needed for my project. Feel free to download the solid models and customize them to suit your unique requirements. Material selection is crucial - while I used PLA for mine, I would recommend opting for a more robust material that's less prone to cracking. ABS or NYLON would be excellent choices due to their durability and resistance to wear.