My Ryobi 40V leaf blower stopped blowing yesterday. The motor sounded like it was spinning but the visible fan blade would only rotate slowly. A quick consult with Dr. Google turned up a few youtube videos of people who had had this problem. One solved it by using a small R/C motor coupling, which also had a well done teardown. The other gooped in a bunch of JB Weld as a fix. Both worked. So I tore mine down to see what was what. I didn't do a detailed teardown, it's trivial to disassemble, but watch that first video I linked to.
All the screws are the same size which is nice.
Ryobi uses these weird offset silicone pieces to retain bearings and springs. I don't like it.
Square shaft for the blower end.
The only other screws are these long motor screws.
The coupler is a 1" long piece of plastic. One end has a square hole for the fan, the other a D shaped hole for the motor shaft. Ryobi does not sell this part, which I consider immoral.
The D hole has been wallowed out round, which is why it's not working. Thankfully the square hole was fine.
I made a bunch of measurements and will be drawing it up in CAD for 3D printing a replacement should it be needed. In the meantime (hopefully it will last forever) I simply tapped in the side of the coupling for a #8-32 setscrew. I used a form tap which should snugly hold the screw and keep it from backing out. This should work for any coupling which just had the D hole rounded out. If the square hole is wallowed out you would probably need 2-4 setscrews that were adjusted so you could just slip it onto the square shaft. This would be a lot harder to get to work well.
It went back together and now it blows again.