in short bearings. in long, on and on. basically the dp bearings aren't as robust or designed to take the side load that a mill's are, the dp takes an axial load while the mills takes this plus a heavy radial load. There are other problems such as no drawbar so what ever you're holding the tooling with will tend to pop out. if you do some searches here and in the some of the metal working forums, there's lots on this topic
Thats interesting because I was going to buy the drill press and get a mill later.
But maybe I should just get a big mill for doing everything?
I will be doing a lot of work with wood initially so thats why I thought a floor standing drill press would be useful by itself...maybe this is not so?
I know Im going to have to get a mill later on for more precise metalwork....but thought the drill press with a suitable bit would do me for a while....
Are you talking about these devices which have an auger bit running inside a hollow square chisel? The square chisel cuts out the corners and deflects the chips into the auger which takes out the center and all the chips.
For this the answer is yes; actually a benchtop mill is the best choice for this because it is more rigid and you can have better control of the downfeed on the quille by using the supplementary feed wheel rather than the hand lever.
About the only thing you can do with a bench drill that is not easily done with a benchtop mill is mount a drill close to the corner of your bench so you can rotate the head to the side and drill the end of long pieces by standing them on the floor.
Ok. Sounds good. Mill it will be....if I can get one that is big enough but not too expensive and will take a morticing attachment.
(Yes the hollow square chisel with the drill bit is for cutting mortices. But they require a special adaptor to mount them onto a drill press and I assume also a mill. They are usually used with a morticing machine which looks kinda like a benchtop drill press)