I used to have a bantam with the D1-3 type chuck but have just acquired a Harrisson 140 & am struggling a bit with the L00 type chuck assembly. Twice now it has come loose whilst doing a bit of gently turning with a rotating centre in the end of the work. The locking ring backed itself up tight against the headstock which was a bit unnerving. I have to say I prefer the D1-3, which was fairly idiot-proof. I've read to use a bit of oil on the taper & threads & make sure they're clean. When tightening do you just put it into a low gear to provide some resistance or do you need to use a strap on the chuck as well? I've been looking all night to find a Doubleboost video where John is changing the chuck (I know I've seen him do it in the past) but annoyingly can't find one. Any advice?