Modified Drill Press

[Gorillakilla]

I was just curious as to how effectively a drill press could be converted to a CNC milling machine. A drill press already has motion along the z-axis and this table can provide movement along the x and y axes; steppers or servos would just have to be mounted to them. My biggest concern is whether or not the spindle could handle the side loading that comes from milling. Any input would be appreciated.

[Karl_T]

My machine shop instructor from 20 years ago allways said, "You can drill with a mill but you can't mill with a drill."

Drills use light wieght bearnings not made for side loads.

Karl

[motomitch1]

Yes It can be done Ive seen one here at cnc zone I cant find it now the guy was using it to make brass-gun barrows for model ships.using very small cutters the MT2 taper with no draw bar could come loose.

[NC Cams]

Yes and no. It all depends on the quality of the press and what you want to do. In a word and IMHO, more NO than yes.

There is usually too much runout for precise machining. Drill chucks make lousy cutting tool holders. The tables that provide X/Y motion that bolt to the drill table are crudely accurate at best. Lousy backlash and poor lead accuracy. THe bearings are usually NOT preloaded in the spindle which when combined with the chuck further causes runout/milling accuracy/finish problems.

Bolt on tables are simply not rigid enough to do anything more that very light milling. The backlash WILL bite you sooner or later.

TO be honest, I got by with a D/P when I didn't have a mill but crudely at best in milling plastic and nylon parts for R/C cars.

A mill will do great drill press work but any drill press i had (even a nice imported new one with tuned up bearings) wouldn't do good mill work. Simply too much slop....

[swarfmacdaddy]

Killa, you can get the same table from enco for $130. I bought one but be warned it has terrible backlash unless you crank the jibs down so tight you cant turn the handwheels.

[MrWild]

I have an extremely cheap Harbor freight drill press. I looked it over thinking maybe it'd work, but I've already discovered the spindle ram to head fitting is atrocious. By adjusting the lock just right, the rattling is reduced, but is still present. When you start to add milling sideloads, the ram will be all over the place. I discovered this problem while drilling circuit boards and the carbide drill was a wobbling blur. If I do convert, it will be with an entirely new spindle that is fitted to the bor of the head. A high quaity benchtop may be better, but if you start buying that kind of quality, you may as well go with a benchtop mill and convert that.

Cheap X/Y table conversions are also fraught with problems. All surmountable, but not an easy thing to do.

[Stevie]

this is the one he mentioned (mine)
It was ok for light duty
Now it looks like this


The Evolution of a Home CNC Mill
the whole thread

[NC Cams]

Stevie:

Now, THAT is a drill press!!!

Reminds me of an old joke where the owner removed the air cleaner and drove a new car undeneath it.

In all seriousness, the billet work is beautiful and it looks like the only remnants of the original drill press is/was the spindle column/casting (which reminded me of the air cleaner comment).

I'd be more inclined to call that a mini-haaz (sic)as it is clearly MUCH more than a drill press.

Again, huge accolades for the beautiful work....

[Gorillakilla]

I appreciate all the input. I know it is a lot of work, but this is for school, and the more work we have to do the better my group will look. My professor just purchased this mill/drill from Harbor Freight. At 700 lbs, moving it was an experience to say the least. We haven't taken it apart yet but the backlash in the table is already evident.

[JohnnyYuma]

Was thinking of using my old ShopSmith (1948 model) it shoud be ok as it can lathe and run a table saw blade. was going though the parts the other day and ran acrossed some small metal lathing cutters.......

JohnnyYuma