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 :D 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.

[John McClanahan]

The chuck falling off is not a model or brand problem. Here is an explanation.

http://www.youtube.com/watch?v=RF1fQTamzYs

John

[Grant Wilkinson]

On my Delta drill press, the end of the morse taper is a rectangular tab. It is not round. The morse taper only fits into the female part on the DP one way. The male tab on the morse taper has to fit into a rectangular mortise in the DP. If it does not, the taper will not hold. Maybe yours is the same???

[ken masoumi]

The chuck falling off is not a model or brand problem. Here is an explanation.

http://www.youtube.com/watch?v=RF1fQTamzYs

John
I have always enjoyed watching "mrpete222's machine shop tips",his videos are addictive,you start watching one and before you know it,you've spent a couple of hours going through more of his tips.

[Andy Pratt]

I had this same thing happen on my dp, problem was that I had used mineral spiritis to clean the taper instead of denatured alcohol (also didn't give it time to dry out after applying). Once I used DNA it has worked fine for over two years. It seems like this is a touchy area where a tiny amount of lubrication is a big no-no so try the alcohol and see if it fixes the problem.

I can't believe the morse taper works as well as it does here but it does work as long as you keep it clean and absolutely not lubricated at all.

[Phil Thien]

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.

This is good advice but I'll only add that, most people don't follow the recommendation to fully clean the spindle and chuck with a solvent, so there is oil left on one or the other (soon to be both) and it will make keeping the chuck in place difficult.

I recommend lacquer thinner. Use it with a rag to clean the spindle, and a Q-tip to clean the chuck. Keep cleaning until you can't get any more oil off the parts. You will know when you're done when the rag and Q-tips don't get dirty.

[Ronald Blue]

As others have said it is essential that both surfaces are free of all oil and dirt. Pop the Morse taper arbor out of the drill press and look at it closely for any nicks or burrs. When you are satisfied everything is properly prepped place the chuck on a solid surface with the jaws retracted and drive the arbor into the chuck. While it's true the arbor has a tang on it that has to be turned to match the spindle that has nothing to do with this problem. The chuck came off the arbor and not the chuck and arbor assembly dropping out of the spindle. This is a "locking" taper and any oil or dirt will impede this from happening. Look closely at both parts to insure that it hasn't slipped at some point and caused it to begin to gall. Good luck. As some others have pointed out this problem has nothing to do with the brand of drill press.

[Myk Rian]

Anyone that has worked with gauge blocks should be familiar with the term "Wringing". This is a way of connecting gauge blocks together without using magnetism, or any mechanical apparatus. It is the process of wringing (twisting the blocks) air from between the blocks, and since the surfaces are so flat, clean, and smooth, they literally stick together.
Basically this is the same process that holds a chuck onto the taper. Surfaces MUST be clean, and the angle of those tapers must match.

[glenn bradley]

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.

The wobble is the culprit. When a chuck is stuck and resists coming off the taper I use a circle cuter without the center bit. This forces a wobble and the chuck comes off after a rotation or two.

[John Downey]

The wobble is the culprit. When a chuck is stuck and resists coming off the taper I use a circle cuter without the center bit. This forces a wobble and the chuck comes off after a rotation or two.

Interesting, learn a new one now and then :D

[Phil Thien]

Interesting, learn a new one now and then :D

It is really better to just use a set of wedges. While the chuck simply lets go about 99% of the time and the cutter just comes to a stop, there are times when the fly cutter + chuck will flip and dance.

[Grant Wilkinson]

Sorry , Gabe. I didn't look closely enough at your pics. Now, I see what Ronald saw right off. The taper stayed in the DP and the chuck came off the spindle. My suggestion was, therefore, useless.

[Glenn Bird]

A retired machinist on another site mentioned that you can use a 20 ga brass shotgun brush (walmart $2, I think) to keep your tapers clean. Cleanliness is essential in maintaining your tapers. Also works well for the lathe.

[John Downey]

It is really better to just use a set of wedges. While the chuck simply lets go about 99% of the time and the cutter just comes to a stop, there are times when the fly cutter + chuck will flip and dance.

Yes, obviously. Just remarking appreciatively on a guy coming at a problem from a different direction when presumably he did not possess the wedges. Lets not get too pedantic about this stuff.