Chuck falls of drill press shaft

I have a small benchtop drill press, A Ryobi of about 20years old.
It has had little use ready over the years and works as intended except that lately the chuck keeps falling off its taper, usually when drilling larger sized holes.
Cleaning the tapered shaft on the drive shaft and in the back of the chuck seems to have no effect. I can not see any rust or dirt or deformity? Tapping it back on and pressing it into the drill plate all to no avail. It is OK for small sized drills but as soon as it it asked to drill something larger - like 12mm, it just slips and falls off.

Does anyone have and suggestions as to a possible cause, and fix, or is it just EOL for this drill press. To all effect everything else is OK

My use is just casual DYI.

The only thing I can think of that may help is to use some thread locker.

i had a similar problem with my old herless, a few years ago. I gave it a polish with some fine wet and dry, and it has done the trick,so far (10 yrs light use).
TM

If all else fails buy a chuck and morse taper. Last time I bought a chuck and morse taper it was less than $50. The chuck that came on my drill had runout so I stuck in the one from my lathe so had to replace that.
Regards
John

Quote:

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Originally Posted by orraloon

If all else fails buy a chuck and morse taper. Last time I bought a chuck and morse taper it was less than $50. The chuck that came on my drill had runout so I stuck in the one from my lathe so had to replace that.
Regards
John

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My read on the original question is that the unit is one of the smaller ones that uses a chuck taper mounting direct to the spindle rather than use a morse taper arbor between the chuck and spindle. I would be tempted to "Blue" the taper on the spindle (colour it with a Sharpie marker), and install the chuck and then remove it. Where the chuck contacts the spindle taper, it should remove the bluing, so this can be used to assess the contact area that provides the grip. My guess is that there are slight differences in the tapers between the chuck and spindle, limiting the contact area and torque that can be transmitted.

Another potential issue that would result in loosening the chuck on the taper with larger drills would be the drill sharpening technique. If the drill sharpening results in the cutting edges being slightly uneven in length or angle, the point of the drill may not be truly centered, which would try and wobble the chuck, potentially working it loose on the spindle taper and causing release. Larger sized drills would be more prone to this as they are both longer and stiffer than smaller drills, so would be more likely to 'work' the chuck on the spindle to release it.

When I have issues with chucks coming loose on Morse taper arbors, my standard approach has been to take the arbor to a freezer for a few hours to shrink it, put the chuck on an a sunny window sill for a similar time, fully open the chuck and rest it with the body on a piece of wood, drop in the cooled arbor, and give the assembly a moderate rap with with a rubber mallet to drive the arbor into the chuck recess firmly. As temps normalise, the chuck recess shrinks and the arbor expands, resulting in a tighter fit. Just very hard to do for a drill where the chuck fits directly to the spindle, though you could try and substitute a few squirts of electronics 'freeze' spray for putting the arbor in the freezer, but I haven't tried this.

Thanks for your reply guys

I have tried the fine sanding (2000 grit) in the past but to no avail.

Not sure of the thread locker idea. Sounds like a recipe for runout I reacon. I had considered this though.

As suspected, there is no arbour to remove and replace with a new one. The taper is machined on the end for the drive shaft.

The blueing idea has interest. I guess it might highlight some high spots to try and paper down. Might look into this.

The freeze can and a heated chuck also sounds like a route to follow.

In the meantime I have borrowed a similar drill press from a friend to complete my current drilling.
I will try out the above suggestions soon, else it is time for a new unit (Fathers Day present?)

An easy fix for this is to clean the taper and the recess and then rub chalk on the taper.
Then do as before tap the chuck back in place,
I am not sure the exact science behind this but it does work.

Morse Tapers are designed to seat tighter the deeper they are embedded so by designed this should be resolved simply by hitting the chuck harder, ie using a block of wood, and a deadblow hammer. Rotate the table away and give it a few solid wacks. If it slips out chances are there is grease or something limiting the friction fit. If this isn't the case dip a rag in some kind of solvent give everything a good clean and try again.

Failing that investigate why its working itself loose with larger bits, i suspect excessive vibration? if so check the belts and setup of machine.


All the best

loctite make a specific glue for this, its often used to glue bearings onto flogged out shafts, can't remember the number but its green.