[JWB_Machining]

Hey,
I know a Drill Press has a spindle that handles loads in the Z direction, Mills have splindles that handle forces in X,Y and Z directions and they have moveable tables. So what's the difference between and Mill/Drill and a Mill. Am I correct to assume it's just a light duty mill? What else should I know about a Mill/Drill before firing one up for some quick roughing work?

[ihavenofish]

i think a mill has x y and z controlled motion. a mill drill has and x and y, but only a lever operated quill for the Z - like a drill.

[handlewanker]

No JWB, the mill drill is just a combination drilling machine that will also just about do mrilling.

It has that goddam awfull round column, that when you start to do milling causes the head to vibrate, due to the round column being too small in diam to resist the side forces of the milling cutter.

They are at best cheap very light duty mills and some have a device that allows you to engage a worm wheel and so move the spindle down slowly.

The XY table is the best part.

The other drawback is that if you want to get more height by raising the head, when you unlock the head and crank it up there is a tendency for the head to move round the column, and so you lose position, and there is no means to accurately maintain position when the head is moved up or down.

The other drawback, but only a minor one and that is the taper in the spindle is most usually morse taper, (about 3 morse), and you can if you're not carefull, get a taper sticking in very tightly.

Like all vertical mills you MUST have a drawbar to hold the taper tooling up or you'll have it drop out under side forces.

Do not be tempted to use a drill chuck as a cheap milling chuck, as it will drop out or release the cutter at the wrong moment.

A milling chuck with ER collets for basic cutter sizes is the best way to go.

Apart from that they will serve as a cheap bench top mill, if the lightness in construction is allowed for.

A new one at $1500 is half the price of a second hand Bridgeport mill at $3000, but is only one hundredth the value.
Ian.