Aiph5u
(Aiph5u (not affiliated with Onefinity))
30
Hey Wayne,
you may be able to find wrenches that give you more leverage, but the root of the problem is the proprietary Makita collet. It only holds the bit at the front end. Reports about this type of collet not holding the bit during use are frequent in this forum. One solution would be a router or spindle with a real ER collet.
It is also good to clean the inside of the Makita collet regularly. Wood dust can be baked to hard but slippery coating inside the collet or on the outside of the bit shank.