[calabrese55]

That is how it grabbed...."When I investigated I found the whole router assembly (secured to the underside of the bench module with four bolts) had loosened over time meaning the entire router was loose!"
No Doubt the bit pivitoted or worse yet bounced into the work from the slop in the router screws and it bit off more than it can chew.
It is however very concerning that the bit came lose from the chuck. One thing to be sure of when locking down your router bits, NEVER bottom the bit to the bottom of the chuck. This (depending on how your chick is designed) could give you a false sense of tight grip on the bit even though you feel a lock on the chuck nut.
I always try to have 1/8 inch between the bottom of the bit and the bottom of the chuck.
calabrese55

 

[calabrese55]

Thanks for your reply and information, I agree with your conclusion regarding the pivoting. The router bit was definitely tightened and set at the mark shown on the router bit (I mark all my bits with black marker to show how far they should be, in the collet). The force damaged the collet and (incredibly) appears to have bent the 1/2” diameter router bit, which now causes excessive vibration to the point it can no longer be used! A salient lesson!

Wow marking your router bits is a great idea wish I had thought of it. If possible can you post a picture of the bent 1/2 inch router bit? My reason is it can serve as a reminder to all of us new and old ( I am old) the need for respect of our tools based on the danger / damage they can create when things go wrong.
Lastly just so you know I am not trying to single you out I had a router incident and I did not fare as well.
Danger never sleeps.
calabrese55