Tube plug (Blue Ox Tow Bar)

thingiverse

I was revamping my Blue Ox tow bar system. It's a setup used to haul a vehicle behind an RV. There are four plastic inserts that keep dirt and water out of the tow bar arms. The original insert was a square fitting into a trapezoid mounted on a cylindrical base. I applied factor gobs of caulk to seal any gaps. One of my inserts was missing, so I decided to 3D print replacements with a better fit. This is an excellent illustration of how custom 3D printing can enhance the original design. In other words, don't insert square pegs into holes that aren't square! Photos show the tow bar system, the original square plug, a test plug for fit, and a red plug made from PETG filament. If the red PETG doesn't hold up long-term, I will switch to ABS or TPU but didn't want to experiment with different filaments and printer settings.