Drill Press Help! My Ignorance is showing.

[Dell Moore]

Yesterday the chuck on my older delta drill press fell off. Having only had my Shopsmith as a drill press in the past, I expected to just put it back on using a set screw. NOPE. No set screw, no nuthin'! What keeps it on?

Could someone please enlighten me about how to put the chuck back on?

Thank you!

Dell

[Tony Bilello]

I dont know about Delta but I can tell you that traditionally the drill chuck on most drill presses have a taper and it just jams in place and held by friction.
If your chuck shaft is tapered, just jam it back in place and tap LIGHTLY with a soft faced mallet or a block of wood.

[Joe Scharle]

Google 'morse taper' and you'll find all you need to know. Meanwhile, don't try to hammer it back on.

[Myk Rian]

Slip it back on the quill shaft and press it down against a block of wood, like you were drilling something.
The chuck coming off is a safety feature in case the tool gets stuck.

[Rich Engelhardt]

Hello,

Yesterday the chuck on my older delta drill press fell off.

Try having that happen while the chuck is turning - fast - and with a 1/4" router bit in it . Exciting only begins to describe that situation!


But - yes - as mentioned it's held on only by friction.
Also as mentioned, just slip it back in place and press fit it into position.

If you whack it with something, you'll knock it cockeyed and introduce a lot of runout.

[John Coloccia]

Before you put it back in, make sure the spindle and the inside of the taper are absolutely, positively as sparkling clean as you can get them. There shouldn't be the slightest bit of dust in there. If there is any dust, you will be rewarded with a wobbling chuck and/or the thing will fall off again and/or you will damage it.

I usually push it in until I can feel it's all seated, and then I tap it a couple of times lightly with a hammer to finish seating it...the keyword being lightly. I have a nice brass hammer that I use.

[harry strasil]

FWIW, the Long taper inside the quill is a Morse Taper, the short taper in the drill chuck is a Jacobs Taper, and its not a safety feature if it comes loose when you stop the drill if you are using too much pressure, it will spin inside the chuck and you will end up purchasing a new chuck and tapered quill piece. Cleaning both the male and female taper is good practice, just don't use anything abrasive to clean it.

Most of the cheap import drills have an almost useless cheap chuck to start with anyway. The first thing to do when purchasing a drill press is to replace the chuck and tapered adapter immediately.

Also standard practice is to use the chuck key in all 3 holes to tighten a bit in the chuck otherwise the bit may experience runout.

[Eddie Darby]

http://www.rvplane.com/pdf/drill_press_tune-up.pdf

[Dell Moore]

OK, while I've got people answering Drill press question, I've always felt this drill press didn't drill "true" straight up and down.

Could this have been because a past owner hammered the chuck back on?

Will "pressing" it back on fix the problem?

If not, is this the time to fix the problem, and if so, how?

Many thanks!

Dell

[doug faist]

Hello,

Try having that happen while the chuck is turning - fast - and with a 1/4" router bit in it . Exciting only begins to describe that situation!


But - yes - as mentioned it's held on only by friction.
Also as mentioned, just slip it back in place and press fit it into position.

If you whack it with something, you'll knock it cockeyed and introduce a lot of runout.

Rich - I curious about your use of a router bit in the drill press. I was always taught this was a no-no because of the design of the router bit (very high speed 15-20,000 rpm). Is there a procedure that you do that can't be done on a router?

Inquiring minds want to know.

Doug

[Barry Vabeach]

Dell, if it is not drilling true, it could be a number of factors, the most likely is that the table isn't plumb to the chuck. Once you get the chuck on, put one end of cut off coat hanger into the chuck and tighten the chuck, then bend the coat hanger so it is parallel to the table, then one more bend so that it is perpendicular to the table near the outside of the table. You then move the quill down while you slowly rotate the drill by hand and you will see whether the table is leaning backwards or forwards, and then check it side to side. Side to side can usually be a adjusted by loosening a nut and tilting it, front and back is corrected by using aluminum foil, or cut up aluminum for soda cans, slipped in between the table and the mount for the table either at the top or bottom.

[Cliff Rohrabacher]

and its not a safety feature .

Yah, there's nothing safe about having your chuck and drill and flopping about the shop at who knows how many RPMs.

The taper is simply an effective means of having an interchangeable chuck mount the taper provided both a locking mechanism and is a high surface area to drive the chuck.

[Rich Engelhardt]

Hello Doug,
Too lazy to use the right tool is all I can say.

It was such a small groove - the DP was there & the router was out in the garage - and did I mention it was just a small groove? Plus, it was late & it was winter & the router was in the cold garage -- and did I mention it was just a small groove?

[Keith Outten]

A drill press and its bearings are not designed for lateral force, only straight up and down drilling. The design of the chuck mount is also for up and down force with no lateral movement.

Drum sanding, milling and routing are lateral force operations, of course we have all done this more than once and I expect we have all experienced a drill chuck coming loose while the spindle is turning
.

[Bob Barkto]

One issue with using most router bits in a drill press is they are designed to cut at high speed and make less than clean cuts at lower speeds, unless you feed the work at a slow snails pace. A 4 flute end mill will wok better but there are more serious issues when using such a tool in a drill press.

That brings up the safety factor of a morse taper letting go under a radial load. Morse tapers are self releasing tapers, they are designed to release easily except under axial load. Any sideways pressure on such a long, slow taper results in a loss of contact, and loss of holding friction. Once the bond starts to break it lets go quite quickly.

Jacobs tapers, like what you see in the end of most drill chucks, are self holding, press or force/shrink fit and will withstand high radial loads like encountered when routing or drum sanding. These short high angle tapers hold really well but they are a more or less permanent fit. It takes considerable effort to release those tapers. Not handy if you interchange tool holders.

Personaly I think the morse taper sockets are a bit dated today. When most drill bits were available with morse taper shanks it made sense, particularly in industrial settings where a tool would be mounted and used until dull and then exchanged with another like tool and so on. It is, however, a more precise holding method, all things being equal and provides for a quicker swap out of tooling.

Delta used to manufacture their home shop/trade drill presses with a unique spindle nose that allowed safe use of tools like router bits in their drill presses while still allowing for easy interchange of tool holding chucks and whatnot.
They had a JT33 taper on the end of a solid spindle, the spindle was threaded on the end. The chucks and other toolholders had a feamle JT33 tapered hole and a mathching threaded collar. Unscrew the collar and the toolholder could be easily exchanged. Yet the JT33 tapered nose held a great deal of radial load.
They also used bearings that could take the side/radial loads, unlike drill presses that feature morse taper sockets. I haven't seen many mt socketed drill presses that were equipped with radial load bearings.

Other methods of restraining morse tapers can work when the spindle is hollow, like on a lathe. Then there is a standard for a threaded rod or draw bar to pull the morse taper in from the non-working end. The morse taper has a matching threaded hole in the end instead of a tang. This results in more or less a self holding arangement, but sufers some loss of accuracy/precision since the long morse taper can still flex a bit under a radial load no matter how it is restrained. You also lose some drive torque as you are relying solely on the friction of the taper to the spindle. On drill presses the tang engages a slot in the spindle hole and this is what provides most of the drive.
This drawbar arrangemet can't be practically done on a drill press because of the way the spindle is mounted and constructed. There is no real room or access for a draw bar.

If your drill press has a morse taper spindle hole you might want to think about loading it with anything other than a drill bit. The results can result in injury, tool damage and/or work spoilage.

Whew, that was enough.

Rich - I curious about your use of a router bit in the drill press. I was always taught this was a no-no because of the design of the router bit (very high speed 15-20,000 rpm). Is there a procedure that you do that can't be done on a router?

Inquiring minds want to know.

Doug