homemade Wood Router - project failed And almost got me seriously injured- READ DESCR

[Claudio HG]

Hey dude, thank you for having posted this video. In my humble opinion the problem was not the speed, but the lack of support. The axis did break at the bearing point, may be because an excessive oscillation or more likely because the bit touched a vein with a sudden change in friction, because these shafts are hardened they are also quite brittle. Slowing down the speed would had not helped, on the contrary might have worsened the risk actually.
The problem could have been avoided by making a second bearing holding a much more ductile shaft that in turn would have held the mandrel. This last shaft would have absorbed vibrations and pressure shocks coming from the contact of the bit with the wood. Again, this is my modest opinion, I am not a mechanical engineer after all
Repurposing electric tools is cool but could be a serious danger as we do not know the calculations the engineers did when they designed the tool.
Glad you were not injured seriously.

Cheers & stay safe,
Claudio