Jacob's chuck installing

[sarabande]

I have a new-to-me heavy drill press

It has a Jacob's chuck, with which I am unfamiliar.

Whilst cleaning the drill this morning, the chuck and its tapered shank came loose (no damage).


I have tried pushing the shank back in, and twisting so that the 'slot' engages, but how does one ensure that the chuck stays where it should be ?

The shank is lightly oiled, not bent, has no signs of previous abuse with a heavy hammer, etc...

What magic words does one use to persuade the shank to stay in place please ?

 

[penfold]

Can you post a picture? Unless there's something wrong or damaged you should be able to put it back by hand, although tapping the end with a mallet can be done for extra security. I assume from your description of a 'slot' it's a morse taper with a removal tang, so make sure it's correctly aligned before whalloping with the mallet.

As it's new it's quite possible that it was only inserted loosely and has just come out from you cleaning; the taper should be lightly oiled(i.e. wiped with a slightly oily rag) to avoid difficulty removing it in future.

 

[Graham_Wright]

There is a Jacobs taper in the chuck itself and a Morse taper to fit in the spindle.

Which one are you referring to?

 

[JumbleDuck]

I have tried pushing the shank back in, and twisting so that the 'slot' engages, but how does one ensure that the chuck stays where it should be ??

It's held in purely by the taper. Make sure that it's scrupulously clean, lightly oil it and push it firmly home: it should stay there.

 

[sarabande]

learning fast !

The bench is about umpty years old, a Fobco.

The chuck end is fine and works well. The problem (if there is one) seems to be at the tapered end which shows a marked reluctance to stay attached to the vertical drive shaft.

The pic shows the taper with the original oil on it. Should I clean this off and also the inside of the taper in the drill, and lightly re-oil it, or install it 'dry' ? There is a slot in the shaft where it looks as if the top end of the taper can be drifted out with a trapezoid piece of metal.


There's more to this engineering stuff than meets the eye Needs scrupulously cleaning for a start, and I thought that oil was a Good Thing.

View attachment 41742

 

[sailorman]

learning fast !

The bench is about umpty years old, a Fobco.

The chuck end is fine and works well. The problem (if there is one) seems to be at the tapered end which shows a marked reluctance to stay attached to the vertical drive shaft.

The pic shows the taper with the original oil on it. Should I clean this off and also the inside of the taper in the drill, and lightly re-oil it, or install it 'dry' ? There is a slot in the shaft where it looks as if the top end of the taper can be drifted out with a trapezoid piece of metal.


There's more to this engineering stuff than meets the eye

View attachment 41742

i would clean that spigot

 

[penfold]

i would clean that spigot

Aye, give it a quick rub with a bit of wire wool or green scourer and a dab of oil to shift the black gunk.

 

[sarabande]

the apprenticeship continues...

View attachment 41746

Spigot now cleaned as instructed, and polished with a dab of chrome cleaner (vintage 1970 or thereabouts).

Internal taper cleaned also, and both parts washed with tractor brake cleaner, and dabbed with Wurth spray oil.

The chuck now slides into the shaft, engages easily into the key, and with light tap from a soft hammer, is now well and truly secure. Now on with the drilling !


many thanks everyone.