Our Hartan Racer baby stroller started to lose its wheels. Turns out that the little buttons in the center of the wheel randomly popped out, releasing the wheels.

Since we do not regularly exchange the wheels, I designed this model as a replacement to permanently fixate the wheels.

Important: This replacement is not meant to be removed again. If you want to replace the wheel, you need to destroy the 3D printed button (I would recommend drilling into it).

Simply pull out the old button and push in the printed replacement. Make sure that the non-straight insets align with the little metal rod in the wheel. They are supposed to push the metal rod against the axle to keep in in place. In contrast to the original design, I inserted an "early" location at which the metal rod is pressed against the axle harder than in the original button. The idea is to go beyond that point to keep the button in place. This makes it a rather tight fit and you might need to gently hit it with a hammer to make it go in all the way.

Anycubic