That could well be a big part of your issue with chatter. The longer that thing is extended, the more it flexes, and flex equals chatter. I use mine as a precision drill press a lot, so I'm constantly swapping the drill chuck in and out. It has its own R8 shank, but is still a lot longer than an end mill in a collet. Thus, the need to raise and lower the head all the time.
Just to be clear, Ed, the sum total of my milling experience is with the machine I have, which I've had for maybe a year. What I posted earlier is based on lots of research on the whole subject of machining rather than personal experience, so I'm sure no expert
. I get along with machinery, and I seem to have a knack for figuring stuff out and making it work, but I also spend a lot of time reinventing the wheel. But I guess that's all part of the fun, too. Later.