June 26, 2020
After years of use, the plastic nub holding the roller had worn down and snapped. I could buy a new one, but they were $150 a piece. 3D printing an aluminum rod was my next idea, but it was still $100. Plastic was cheaper at $50 and won't last as long; its strength dubious as well.
The last idea is to drill a hole from both sides and insert two short metal rods. It was risky because it sounded incredibly difficult to drill a straight hole into the plastic. But it was going to be a piece of garbage anyway if I didn't fix it, so I ordered 3 pieces of 5mm stainless steel rods from AliExpress. Just when the lockdown started.
After three months, they arrived. I got to work. I hit two snags - I didn't have a metric drill bit and the closest imperial size was too big for my liking. Also, drilling into thick plastic wasn't easy. At higher rotational speeds, the friction got too great and melted the plastic. Instead of crushing and pulling out pieces of plastic as I drilled, I was mixing heated plastic goo in the barrel. I stopped using the Dremel and used a slower speed instead with my regular drill.
The larger hole was actually an advantage. With some grease, the rod had just enough friction to stay in position once I inserted the roller into the frame. The result was a smooth roll, better than new. All for less than $2 in material costs.
Take that Armaid!