View Single Post
  #30   Report Post  
Posted to rec.woodworking
Joe gwinn Joe gwinn is offline
external usenet poster
 
Posts: 416
Default Drill press dado

On Sun, 22 Nov 2020 17:51:07 -0500, wrote:

On Sat, 21 Nov 2020 19:45:38 -0500, Joe Gwinn
wrote:

On Sat, 21 Nov 2020 17:50:55 -0500,
wrote:

On Sat, 21 Nov 2020 11:26:28 -0600, dpb wrote:

On 11/21/2020 8:12 AM, JayPique wrote:
On Friday, November 20, 2020 at 6:45:13 PM UTC-5, wrote:
snip
I have a Rockwell/Delta 11-280 drill press. The manual discusses its
use as a router and a shaper. In fact the manual displays a shaper
cutter kit. I haven't used it as either a router or a shaper. But I have
used it as a drum sander.

http://vintagemachinery.org/pubs/1141/2952.pdf

This isn't a good idea. As has been discussed in this thread
(recently at least), sanding/routing/shaping will put a side load on
the bearings. Drill presses aren't designed to handle force
perpendicular to the bit. This is just asking for terrible runout
when drilling.

I agree. That said, for light duty you could use something like this to minimize the damage...
https://www.leevalley.com/en-us/shop...m?item=68Z0220

And you don't suppose Rockwell designed/picked the bearings to handle
suggested uses of the machine?

No. The mounting is all wrong. No matter what, you're not only
putting a side load but torque on the bearing.


Really? How does that work? How is it different from the loads
imposed by drilling?


You're cutting/shaping/sanding sideways putting torque Against the
side of the bearings. Drilling is a vertical operation and puts no
stress on the side of the bearings/shaft as they were designed. Add
to that the leverage of the length of the /bit/quill/shaft and a it's
significant stress in a way the machinery wasn't designed to operate.


You are assuming that the manufacturer did not design for these loads
in a machine sold as being able to do just this. Ball bearings are
very strong, and if only woodworking precision under woodworking loads
is needed, quite cheap.

Hmm. I wonder what kind of bearings this Rockwell/Delta 11-280 drill
press uses. Google. Seems to be a pair of ball bearings at top and
bottom of the spindle, plus a radial needle thrust bearing at the
bottom. So there is a pair of bearings next to the chuck, and the
ball bearing will handle side loads, while the needle thrust bearing
will handle axial (drilling) loads. So, use for making dados is quite
plausible.

Knowing Delta, these will be comodity bearings, and easily replaced
even today.

The replaceable bearing mentioned by others is for the cone pulley at
the top of the drill press, and is unrelated to side loads on the
drill chuck.

Joe