My fix for hair seizing the brush ball bearing.
The original ball bearing is replaced with two smaller ball bearings which are located out of harms way inside the brush tube. The shaft/axle which sticks out the brush end does not rotate. This creates space for the hair to wrap around the non rotating axel and not press directly against the sealed ball bearing, provided you clean and remove the hair every now and then. Moving the ball bearing creates the opportunity for the entire brush to get closer to the wall side bumper and rely less on the side brush. I was tempted but opted for more space for hair. The copper washer is because the flare diameter was slightly small.



The bearing spacers are made from of ¼” copper plumbing tube. The outer tube is 3/8” copper plumbing. A thin steel plate (part of a washer) mounts in the original ball bearing position and centers the axel. The axel is a ground 5mm x 100mm high speed steel shaft (overkill, it can break but it will never bend) cut in half. Two 5mm x 8mm sealed ball bearings slide onto the shaft and are positioned with ¼” copper tubes. The last tube on the shaft is slightly squished to make a snug fit which keeps the assembly together when removed for cleaning the hair away. The 3/8” plumbing tubing that I have has an 8mm inside and 10mm outside diameter. One end of the 3/8 copper tube gets flared to retain the brush beaters and bristles from sliding out of their groove and the other end is cut with a tube cutter which reduces the tube diameter slightly and stops the inner ball bearing from sliding all the way through the 3/8” tube.
The shaft is welded to the center of the 16mm diameter steel plate.
The plastic brush has an inside diameter slightly under 10mm but it also has two projecting key ways which need to be removed. I used lettered drills V, W, and a 25/64” to get a round hole with a snug fit on the 3/8” copper tube. The flaring was done in a vice which increased the copper tube diameter slightly so do the drilling and snug fitting testing last. I also counter sunk the brush end to accommodate the copper tube flare.
An alternative design could use a pair of 5mm x 10mm bearings with no 3/8” copper tube. The bearings just get pressed into the brush end; however, if the bearings ever jam the heat from friction might become a plastic melting issue. I expect the 3/8” copper tube will distribute any bearing heat if the bearings seize. If the welding is not an option you can glue the axle into the small ball bearing and glue that into the original ball bearing. This reduces the space for hair to accumulate so it would be my last choice.
Peter