OK, problem solvers. Delta drill press question.

[Gabe Caraway]

I don't use my DP350 much; maybe 20 times in the last 3 years. Today, I was using it to rough cut two large mortises using an extension and a forstner when the chuck just fell our of the machine.

A simple google search showed that I could rubber mallet the chuck back onto the spindle because it uses a Morse Taper. This isn't my favorite tool so I have no problem laying into it with a mallet. However, it doesn't seem to want to seat down all the way.

I've attached pictures. What can I do to get back to work?

Thanks for any help. I'll be back in about an hour.

[Charles Taylor]

I don't own that model, but I do have two other Deltas, and the same thing has happened with one of mine. That looks right to me; there is room above the chuck to insert wedges to remove it (intentionally) should you ever want to.

[Kyle Iwamoto]

Clean both parts with a good cleaner such as acetone or denatured alcohol. The problem is you have lubricants/dirt/debris on the morse taper. Then whack it up there. If you use WD-40 etc to clean, it will just fall back out.
Your Delta is colored like a Jet......

[Kent A Bathurst]

Do it. That is exactly the way it is done. Or - block of wood on the table and use the handle to force it down.

I use a block of wood and a smallish steel sledge - about 1.5# head.

But - if you properly seat it once, that should last a long, long time. I have helped a friend asse mble a modest shop over the years. One was a nice Jet benchtop DP. He called me freaking out because the same thing happened to him. I told him exactly what I told you. He says - not kidding "Oh - Yeah. I remember reading about doing that in the owner's manual setup instructions. I guess I forgot to do it." Me: Ya THINK?"

On big-time industrial DP's, they often don't even use a chuck. Their bits, etc., are mounted on tapered posts and they seat them directly into the MT. You should see a vertical slot on the side of the quill - an angled piece of metal called a "drift" slides in there - whack it in, and it will release the chuck/tool.

[John Downey]

What makes you think that's not on all the way? Looks about right to me.

I've had the same thing happen to my mortiser, it happens with Chinese stuff more than it should. I put some loctite on the taper (The short one for the chuck is usually a Jacobs taper) and it's held fine since then. If yours falls off again that may be the way to go.

[Charles Lent]

Clean the tapers (both male and female) with mineral spirits and inspect them to be certain that they are both very smooth. Then put them together using the mallet or dead blow hammer. An alternative to the mallet is to press the chuck hard against a piece of wood but I prefer the mallet or dead blow hammer. Don't use a steel hammer. You don't want to damage the chuck, just drive it home. The Morse taper is there to let you replace the chuck or use other tooling having a Morse taper. It's a great way to connect tooling, but it can be a bit of a pain to get it to seat properly. Once it does seat properly I doubt that you will ever have this problem again. If you should ever need to take them back apart, there is a slot in the side of the drill press quill (lower the quill toward the table and you will see it) and you can drive a wedge into this hole to push the Morse taper apart.

Charley.

[Thomas Hotchkin]

Gabe
I like to have both surfaces on a taper fit very clean. Then with your chuck fully open heat it to no more then about 120 degrees, kitchen oven does a great job. With some wood blocking under DP spindle quickly place chuck on the cool DP spindle and use your DP feed lever press it home. No need for a hammer. Works for me. Tom

[Gabe Caraway]

Well, after a proper cleaning and good whack or four with the rubber mallet (I'll try the wood block next), it falls back out when I begin to use the extension and forstner.

The problem may be there. The forstner and (cheap) extension have a slight wobble not present with a drill bit. I wonder if the wobble is the culprit since I've headed all the good advice here with no luck.

[John Downey]

Well, after a proper cleaning and good whack or four with the rubber mallet (I'll try the wood block next), it falls back out when I begin to use the extension and forstner.

The problem may be there. The forstner and (cheap) extension have a slight wobble not present with a drill bit. I wonder if the wobble is the culprit since I've headed all the good advice here with no luck.

That's what my mortiser did too, once it came off there was no reseating it. I didn't try heat though, that's not a bad idea. I guess how well that would work depends on the cause in the first place. I concluded mine was a badly matched set of tapers, and went for the expedient solution - glue A sharp heat/cool cycle should pop it off if I ever need to remove it.

[Bill Huber]

Worst case, go to the Auto parts place and get some fine value grinding compound and put a little on the drill press shaft and then put the chuck on and turn it on the shaft. After doing this for a little bit you can then take it off and clean the shaft and the inside of the chuck really good and it should seat good again.

[pat warner]

I'd bet the spindle is boogered. Booger dat & you need some machine work not a hammer.

[John McClanahan]

I have the same drill press. That hasn't happened to me. The wobble of the bit can make the chuck turn loose. So can using a drum sanding attachment. As others have said, the mating surfaces must be clean, dry and without any kind of scars. Open the jaws fully before whacking hard with the mallet. Don't hit the jaws. Also, the taper is a Jacobs taper JT33.

John

[John McClanahan]

Gabe, that drill press had a design flaw that would cause the variable speed to break. To top it off, Delta stopped selling the replacement part. Take the top cover off and make sure the pin that goes thru the end of the motor shaft (at the top) can't back out. Mine tried to do that, but I caught it before anything broke. I used a zip tie as a clamp to keep the pin in it's proper place.

John

[John Stankus]

Funny, I had the same thing happen yesterday trying to use a hole saw on plexiglass. I guess the plexiglass was a bit more grabby and the torque on the 2 5/8 hole saw loosened the taper.

What I recall doing to seat the tapers in a chuck, back when I helped maintain the chemistry machine shop in graduate school, was to chill the taper rather than heating the chuck.. We used liquid nitrogen, but dry ice should work as long as you don't condense water on the taper. (Caveat: I am not a formally trained machinist)


John

[Myk Rian]

I got rid of my DP 350 because of problems that weren't worth the trouble to fix.
Such as the chuck falling off, and the roll pin in the Reeves drive coming loose.