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I have an old Northern Drill Press, which has a MT2 taper spindle. I have added an XY mill table, hoping to use the machine as a mill. However, the spindle of the Drill features a solid spline shaft, which drives a tube with a MT2 taper. Is it possible to replace this assembly with a tube type shaft, so that a drawbar can be used to secure the chuck, or collets? Has anyone else done this particular conversion? I am not in my shop to check the dimensions, but as I recall the spline shaft diameter is rather small. Like .750" or maybe even 1".

[Fastest1]

Generally you wont find people who support this modification. Of course there are always people who have done it due to necessity. My understanding is that the bearings are designed for a downward load and not a side load. How about a MT2 to ER collet adapter?

[awerby]

I don't think that's going to work too well. If you really have no alternative, then think about removing the whole MT spindle assembly and replacing it with something else that's designed for axial loading and won't fall off when you start milling. But really, keeping this as a drill press and finding a mill would probably be a better idea...

Andrew Werby
ComputerSculpture.com — Home Page for Discount Hardware & Software

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I have already built a Router Table which is in essence a combination Mill and Lathe (4 axis machine). However, being unemployed I just can't afford the investment to replace the Router with a VFD and spindle, which would give me the mill I really want.
I just thought that with Northern being such a common brand of cheap shop tools, someone on here may have addressed the problem. And could offer suggestions.
And yes, I agree that removing the entire assembly, and replacing it with a modified spindle is probably my best option. However, I feel sure it would require a larger diameter of casting to work with than the drill press is equipped with. In order to bore the casting out for the larger radial/axial/thrust bearings it would require for best results.
My main question, is whether or not the small diameter spline shaft could accommodate being bored thru the center, for inserting even a threaded rod to be used as a drawbar to secure the chuck in the spindle tube. Even a 3/8" 16tpi rod would at least provide a way to lock it in the spindle tube.

[DareBee]

If you want to drill a hole in the middle - just do it.

[gun_mike]

I tried to to convert a drill press into a mill. What a waste of my time. i got better results with a milling attachment on my lathe. However it was a fun project. I suppose it would be okay if u want to take light cuts all day. I would highly recommend fitting a digital caliper slide to the quill so you have an idea where your tool tip is at.
just my 2 cents
Mike

PS I was able to drill through my spline shaft and use a 1/4-20 piece of ready rod for a makeshift draw bar. Without the draw bar, my MT3 endmill holder would just fall out of the spindle at random times during machining. I also tried to remove the quill and put AC bearing around the spindle. I made clamps to adjust the play around the column and I added a 1 1/2" bar on the back to stop the head from twisting. Also I used 1/2-10 ACME rod for a Z-axis lead screw. The whole contraption was very smooth to raise and lower the head, but it was terribly un-rigid and produced poor finishes at even small DOCs.

http://vincechanblog.ca/cnc/cnc.html this was my inspiration for the second half of my conversion

[GrievousAngel]

Any info on this?

Thanks,
William

[handlewanker]

Hi, back in the late 70's I tried to convert an Atlas bench drill to do milling, by fitting a 3 morse taper spindle........took some doing......lack of draw bar made it iffy.

The whole problem was the round column that did not support the head casting sufficient to do milling.

You might improve the set-up by bracing the head casting back to a wall and adding an old 6" 3 jaw chuck to the top of the spindle splined shaft to act as a flywheel damper, but when you can find mill drills going fairly cheap, and they're also a heap of sh!t, the work involved is wasted.

As the man said, you can get better results milling in the lathe with a vertical slide on the cross slide.
Ian.

[Winnfield]

I remember reading something somewhere on Bob Warfield's site, I think, about a guy who had a phD in Mechanical Engineering that did it. There used to be a link to the site where he showed it, but I remember having trouble finding it. There are countless college engineering senior-projects on the subject, though, so you should be able to find something somewhere.