Dumb Drill Press Question

[Charlie M. 1958]

I just purchased my first drill press (Delta 12" benchtop DP-300L). I'm not totally new to drill presses as I used to fool around with my dad's when I was a kid.

Having never assembled one before, I was shocked to discover that the chuck is installed by simple tapping it on to the tapered shaft. What little common sense I have wants to tell me that the laws of physics work against this thing staying put. Can somebody explain the reasoning behind this design? I now have visions of the chuck flying off at high speed and ricocheting around the garage like a top.

[Doug Miller]

Friction fit. It isn't going anywhere. Don't lose sleep over this.

[Robatoy]

Make sure the tapers on the shaft (trunnion) and inside the chuck (bore) are squeeky clean. A light tap upward, and it will stay on....like REALLY stay on. Google >Morse taper< for more info.

r

[<marierdj]

With your kit you have a wedge. Do not loose it. It is used to remove the chuck assembly. After a while it becomes impossible to remove the Morse taper assembly without using this wedge and tapping lightly with a hammer.

[DonkeyHody]

The Morse Taper dates back to about 1864. It is the standard method of attaching many rotating shafts together, including chucks on drill presses. If you tap it solidly into place, it won't fall out.

DonkeyHody "Even an old blind hog finds an acorn every now and then."

[Andy Dingley]

Yes, it's a miracle it works. Frequently they don't.

This _isn't_ a Morse taper. There's a short taper in the back of the drill chuck and there's a double ended shaft that joins it to the Morse socket in the quill shaft. The short taper is usually a B16 these days, older ones may be 0, 1 or 2 JT (Jacobs Taper).

More details.

[Phisherman]

It is a friction fit. It is very important to thoroughly clean both mating parts before you tap the chuck in place. Do not put any fingerprints on the metal.

[Toller]

I bought a barely used drill press and was really shocked when the drill and chuck fell out. They are balanced so they don't shoot anywhere, and really don't have all that much energy anyhow.

Turns out they were all greasy; apparently the guy didn't read the assembly instructions. I cleaned them up with acetone (mineral spirits weren't adequate to the job) and it has been fine since.

[RonB]

Don't worry. Just clean the taper and the hole and put it together. As I recall my instructions told me to put a block of wood on the table, clean and insert the tapered shaft; lower the chuck onto the wooden block and use firm pressure on the plunge-handle to press the taper into the hole. I did that with mine about 25 years ago. Still there.

RonB

[Rick Samuel]

Before tapping the chuck onto the taper, OPEN the jaws so they are inside the chuck body, hit ONLY on the face of the solid body.

[Roy Smith]

double-ended intermediate at all.

[Edwin Pawlowski]

The reasoning is that it is simple and works. Do not, however, apply a lot of lateral force for some reason (like trying to use a drill bit like a router) as than can make it come off. No, it won't go flying around, it just sort of drops.

[A.M. Wood]

"Certain types of small tools and machine parts, such as twist drills, end mills, arbors, lathe centers, etc., are provided with taper shanks which fit into spindles or sockets of corresponding taper, thus providing not only accurate alignment between the tool or other part and supporting member, but also more or less frictional resistance for driving the tool."

A.M. Wood

[lwasserm]

I don't think the OP will hurt anything either way, but on a common Jacobs plain bearing chuck it's better to strike the JAWS than the SHELL of the chuck.

[Charlie M. 1958]

Thanks to all who replied. I feel better knowing that the chuck isn't going to come flying off like a projectile. I did follow the instructions to clean the surfaces, and it seems to fit securely.