I need to get a Life besides Repairing/Enhancing!!! I enjoy helping and what I noticed is what could
be a failed “Pop Rivet”. It could allowing
the button not to respond and easy to wear.
Take a close look and the rivet has to be close to the end and flat or flattened
to work.

Am I close to the problem??? If so, tightening the clamp tighter reduces
wear and grease could help. If there is
no Quick Clamp there needs to be one to tighten and reduce wear. Please show a good Pic (with light) of the wear/problem
at the joint. Force you flash to work by
reducing light or auto flash if needed.

Since we have the other post re Ryobi tool, I looked at the button. As loger says, it is retained by a small pop like rivet. A regular pop rivet would be way too big and in the way. On a Ryobi, the button is on (or part of) a flat but springy piece of metal. I would imagine that a button could be created by bending one end of such a strip of metal into a little 'U' to act as the button. But I don't have an easy way in mind to anchor it. I suppose some real small riveting tools would work, but I have no experience.

1. The Lower Straight
   Shaft Assembly was possibly planned to be replaced when warned.
2. I can see a double clamp at the joint solving the
   matter with “Good Torque”. Possibly
   2 will have to be welded leaving some tightening material past the weld.
3. This is typical of Multipurpose Tools/Machinery.