Re: Drill-press for milling?

["Finn Hammer" <f-hammer-at-post5.tele.dk> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Dan!

I would advise against trying it.

The reason is, that there are some differences btwn. milling machines
and drillpresses, however alike they may seem. these differences favour
the milling machine with greater stiffness, and the drilling machine
with longer and faster travel of the main spindle.

Millingmachines have tapered roller bearings, pretensioned, so that
there is no radial and axial play. The chucking of the endmill is by a
double tapered collet, which chucks the endmill into union with the
spindle. All this ads up to a very stiff assembly, which will be able to
sustain the cutting forces without much deviation from the centerline.
Thus it is able to apply a cutting force to the material being milled,
without bending away. 

If you try this on a drill press, the lesser bearings, and the
drill-chuck with large overhangs will bend out untill enough pressure is
established to initiate a cut. Once the cut is under way, the press will
return to normal position, and the resulting chip will be very thick.
This may lead to the endmill "walking allover the armature" and probably
break the mill, damage the armature and bend the spindle of the
drillpress.

Instead I`d advise you to invest in a coarse, 12" long flat, crosscut
file, and do the armature by hand. That`s how I do myself, and it only
takes around 30 minutes to modify a motor. The file is great for all
sorts of other jobs, like straightening the edges of rough cut copper
plate, you may well get fond of it.

I did 4 years of toolmaking apprenticeship, 14 weeks of filing school,
so maby I am forgetting that filing is an art that takes time and lots
of practice to master.

Perhaps better go by the angle grinder method. 

Hope this helps,

cheers, Finn Hammer 

Tesla List wrote:
> 
> Original Poster: "Dan and Nancy" <ntesla-at-logicsouth-dot-com>
> 
> Hi all,
> I have a drill-press, some end mills, and an x/y milling vise.
> Would it be possible to mill flats on a motor armature for a synchronous
> gap using this setup? The drill-press is fairly heavy duty.
> Thanks,
> Dan Kline
> ntesla-at-logicsouth-dot-com