Hi all,
Finally got my slot mortiser set up (an accessory item for my under and over/ jointer-thicknesser) and after a bit of trouble sourcing bits I finally received a very nice packaged set of CMT(?) bits.
However, on my second use of the machine the bleeding chuck came loose and fell off the tapered shaft (I think it's called a jacobs chuck) when I powered it up. Consequently damaging the cutting edge of the bit that was in at the time as it rolled around in the unit below where it fell off.
I have read that tapered shaft chucks are not designed for the sideways forces of slot mortising. My method was plunging the bulk out of the mortise then sliding left to right at increasing depths until the mortise was cleaned out. I think the vibration that occured during that process must have loosened the chuck.
I had tapped it onto the shaft originally but since that happened I have hit it on with a hammer a fair bit more forcefully.

Would you say that the manufacturer has cut costs by not using a threaded shaft mount for the chuck or should it be satisfactory as it is now that it is whacked on a bit harder? Hoping not to have a rerun of a chuck on the loose in the workshop at 3000+rpm again... especially given the cost of slot mortising bits...