Chuck keeps falling off Drill Press

[anoldfart2]

I have one of those inexpensive small bench top drill presses. It's worked pretty well over the last 2 years since I bought it at a local auction. Yesterday I had to drill a 1/2" hole in some 1/8 steel. I was drilling when suddenly the bit got stuck. I rasied the lever, and the chuck fell off the shaft.

The chuck and shaft are tapered, but there is no flat side. It's basically just pressure fit due to the taper. So I put it back on the shaft and tapped the chuck upward with a hammer. I started to drill again, and once again the chuck fell off. This continued to happen. I finally took a heavy hammer and really beat the chuck onto the shaft. 30 seconds later it fell off again. I repeated, hitting even harder, and once again it fell off.

At that point I said the hell with it and used a hand drill.

Is there some trick to this, or something I am missing? There is no screw inside the chuck (like the hand drills), no pin, no threads, nothing like that. How the hell is it supposed to stay on, and stay tight on that shaft?

Either it's badly worn, or I am missing something. It does not look to be worn....

Anyone got any suggestions? I am seriously considering using JB weld, but I know it will never come off again. However, the press is useless as it sits now.

It even fell off before when I drilled a 1/4" hole in a 2x4 scrap, while I was trying to fix it.

Thanks

[jimmy]

I've had good results by getting the chuck really hot with a propane torch and then using a piece of wood between the chuck and the hammer to tap it tight.

[Edwin Pawlowski]

The taper must be perfectly clean. Use mineral spirits and then let it dry. Put the chuck in place and just give it a tap with a hammer and a piece of wood as a block. Tapered chucks are on millions of drill presses. It is possible that your unit has a bad spot, but it does work. They are not good at taking a side thrust though.

[yourname]

ink it up[would use dykem, but I 'll bet you have a sharpie] and spin it lightly in the taper to check for a high spot. If you find one, gently ohso gently wiht a fine file.

Most likely you have exceeded the capacity of the drill chuck/taper.

I have had good luck with red loctite. beating is counterproductive.

[WConner]

I have seen where some people use valve grinding (lapping) compound to seat the taper in the chuck to the taper of the quill. These two surfaces will need meticulous cleaning afterwards of course.

Walt Conner

[Rich]

Put the chuck in the freezer for 30 minutes or more then take it out wipe off the sweat and then seat it. It will expand and stay put.

Rich

[yellowbirddog]

If there's been no galling of the surfaces (male or female) during the incident you described, there's a chance the taper was poorly made to start out with. Machinists will often check tapers by rubbing them with chalk, seating them, and the removing them to check for signs of uneven fit. Depending on how bad the problem is, they'll take an emery cloth to it while on a lathe, or they'll take another cut at it. Hopefully, your taper has only a minor flaw that can be polished down.

Get out the chalk and magnifying glass. Be sure to clean the chalk off really good when you're done.

[Tim Killian]

[RicodJour]

Small wonder. The thing spins like the dickens and he probably got dizzy. ;)

R

[andynewhouse]

I would just try cleaning both surfaces carefully with mineral spririts and then tapping the chuck on with a block of wood between the hammer and the chuck, as Edwin mentioned above. If it wasn't damaged by previous hammering, this should work. I would NOT put the chuck in the freezer - if anything, you should heat it, and then its diameter would shrink as it cools and hold it onto the spindle. Shouldn't be necessary, though. I definitely would not use JBweld either, as this could defeat the whole purpose of the spindle taper arrangement, which is to keep the chuck exactly centered with the drive shaft. Good luck, Andy

[George E. Cawthon]

That's backwards. If you put anything in the freezer it should be the quill. Freezing the chuck would just make the hole smaller, which means it would go on more tightly and then when it warms the hole gets larger and if falls of the quill even more easily.

[Chris Lewis]

Perhaps not backwards. Depends on what comes off with the chuck.

My drillpress has a female taper in _both_ the quill and the chuck. They're attached together by an adapter that has a male taper on both ends. They're different tapers... Many DPs will be like this. I'd also imagine that some DPs have the adapter bolt to the chuck (like a portable drill chuck).

When I've had "falling off" problems, it's always been the quill end, and the adapter has stayed on the chuck. So freezing it would work. If it didn't dislodge the chuck-adapter taper ;-)

A good cleaning with alcohol or degreasing agent is usually the trick.

[George E. Cawthon]

I've never heard of an adapter or a female chuck in any discussion on chuck falling off. So, I was not aware of this possibility. However, I think the assumption in this discussion was that the chuck was female and the quill was male.

[Chris Lewis]

According to George E. Cawthon :

The quill on my DP is a female #2 morris taper and the chuck is a female "R8" (I think) taper. The R8 is quite stubby and wider than the #2.

[There's the Morris #n series, plus IIRC, Rn, and Jn standard tapers.]

This configuration is very common at least in the larger units.

My DP is a heavy duty bench model - an inexpensive knockoff of an industrial unit I suspect.

Most of the conversations I've seen about chucks falling off have turned into people siliconing their chucks on. I don't think they care enough to look very closely.

Few people these days really appreciate what tapers are for. The only other place woodworkers see them is tailstocks of mid-quality and better lathes.

After taking machinist courses, it makes me cringe when people glue 'em together. All of their DPs had female tapers on the quill, and special levers to make disengaging them easy so you could swap the chuck for something else. Mine has a slot in the side of the quill so you can drive a wedge in to pop out the taper.

But, if all they're ever going to use in their DP is the originally supplied chuck I suppose I can't argue.

But they do prevent themselves from using things like large size twist drills that have #1 and #2 morris tapers, and mount directly into the quill (there are sets that go all the way from 1/2" to 2" or more in diameter - I'm waiting to find mine at an auction - bought new, they're a bit on the pricey side).

[Brian B]

replying to anoldfart2, Brian B wrote: Why is Chuck standing on the drill press? Tell him to get off!

Sorry, had to do it. :)

Brian

[bob_villa]

Brian, you're a little slow on the uptake...over 10 yrs and no one's laughing!