Chuck key for Fobco pillar drill ?

sarabande

sarabande

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I have an elderly Fobco Star bench pillar drill, in need of some TLC. In particular, the chuck will not turn to open the jaws for the bit.

I have soaked it in penetrating oil, and read that sometimes gentle persuasion with a brass hammer will free reluctant parts. Some heat will also be applied from the Leinster air torch.

Also, the chuck key appears to have evaporated. I have measured the pilot hole dia as 7.1mm, but it is likely that the chuck is imperial ? (Possibly a Jacobs chuck ?) Any suggestions as to how to find the number of teeth required please, or do I order 7mm keys with varying teeth numbers till I find one that fits ?
 
My Fobco has the original Jacobs no. 34 1/2" chuck. It uses a Jacobs K3 key which is readily available AFAIK.
Edit, just measured my K3 key, it's 5/16", ie 8mm, so too big for your chuck. A 3/8" Jacobs chuck that I have has a key dia. of 1/4".
 
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Norman, that is now going into realms of the unknown. I understand, and like, the idea of a keyless chuck, but removing the present keyed one is a bit of a challenge as I have never done it before.

i think I will try Earlybird's suggestion first.

thanks both.
 
To remove a chuck on a pillar drill with a taper shank get a tapered ball joint remover and ue that between the chuck on the underside of the pillar drill shaft

Photo-1.jpg
 
sarabande said:
Ah, Roger, I see how that works.

Another stage in the process - now to take more measurements !
Click to expand...

You may need a bigger hammer than shown

I have the reverse. The taper on my pillar drill is damaged so sometimes my chuck falls off when I withdraw the drill bit.

I fixed it with some fine grinding past on the taper of the machine and the chuck while running the machine.
 
Pull the quill right down. On most drills with a morse taper fitted chuck there is a slot in the quill which matches a slot in the spindle, through which you can see the tang on the end of the chuck taper. You use a tapered drift, easily made from a piece of mild steel, to release the taper.

Rogershaw's method may well pull the chuck off its taper fitting, leaving the Morse taper behind in the machine spindle. The use of a tapered drift as I describe is the best method, and carries no risk of damage.
 
Norman_E said:
Pull the quill right down. On most drills with a morse taper fitted chuck there is a slot in the quill which matches a slot in the spindle, through which you can see the tang on the end of the chuck taper. You use a tapered drift, easily made from a piece of mild steel, to release the taper.

Rogershaw's method may well pull the chuck off its taper fitting, leaving the Morse taper behind in the machine spindle. The use of a tapered drift as I describe is the best method, and carries no risk of damage.
Click to expand...
This^^^
If this is the case, then any new morse adaptor wants a 'tang' to remove it.

Or possibly there is a drawbar pulling the taper up from above? More usual in a mill.

Personally I find keyless chucks are best kept for machines with controllable reverse, it's a lot of turns to go from small drill to big.
 
Although a later version of the Fobco Star was made with a female 2MT spindle, most have a male Jacobs taper, 6JT for direct chuck mounting. No drawbar.
The OP's chuck, with 7.1mm holes, seems a bit of an oddball
 
earlybird said:
Although a later version of the Fobco Star was made with a female 2MT spindle, most have a male Jacobs taper, 6JT for direct chuck mounting. No drawbar.
The OP's chuck, with 7.1mm holes, seems a bit of an oddball
Click to expand...

Mine has a Jacobs taper as If i remember most small bench drills have is only the bigger pillar drills (floor mounted) that have a longer quill to take the longer morse taper.

Of cause if the OP does have a morse taper quill a taper wedge is the way to do.
 
If its the sort with a solid spindle then Rogershaw's method is the only way, but needs care and ideally a pair of wedges so that an axial force is applied when the two are squeezed together by a clamp.
 
Norman_E said:
If its the sort with a solid spindle then Rogershaw's method is the only way, but needs care and ideally a pair of wedges so that an axial force is applied when the two are squeezed together by a clamp.
Click to expand...

It the similar to the way you can removing a prop from a tapered prop shaft . 2 big hammers hit simultaneously from the opposite side.

That's of cause if the chuck knickered as I think the OP's chuck is.

Also if the geared part of the chuck is jammed the 2 hammer method could alo free the chuck.
 
Progress ! I took courage in one hand, a lump hammer in another, and masonry chisel in the third. :)

Having checked the quill for slots (none, only the gear teeth for the feed handle) I gently inserted the chisel into the gap between the chuck and the spindle clamp, and tapped.... After a few blows of decreasing gentleness, the chuck fell from the spindle onto the cloth I had laid on the table, and the rest was just standard fettling with oil, a bench vice and a pair of 18" footprints.

When I bought the drill, I was told that it had been replaced by one of the early CNC machines, and had been moved to a side room and stored and forgotten for 20 years.

The spindle is a taper of as yet unidentified type, and the chuck taper recess looks as if it had been set on day 1 and never moved since then.

The chuck body, jaws, teeth ring and all the sliding parts now move easily and smoothly as a new one. I am reluctant to soak it in petrol, so a light oiling and then replace it on the spindle having cleaned and polished the taper and chamber, set it, then spin it up inside a soup tin at high speed to fling any remaining lube oil out before I use it properly.


I have now been able to check the diameter of the pilot holes for the key and it is indeed an 8mm one. Previously I had only measured on one hole and that had a bit of crud in it. Another lesson learned. Bit diameter is max 13mm, so more than enough for my modest uses.

NormanE, Rogershaw, Earlybird, and Tern, I do owe you all many thanks for the technical advice and the encouragement. I have always admired Fobcos, and this one just "talks" to me after all the years in a dark corner of an engineer's workshop. Good old-fashioned British engineering back in action. Lots of cleaning, a bit of de-rusting, and removal of chrome plate peeling bits that cut fingers, and then off on some long-delayed boat projects. Oh, and I might treat myself to a flexi LED lamp and some really nice bits :) And an 8mm Jacobs (?) key

Thanks again everyone.

Chuck on desk . Note jaws/collet now working.
x8ByIcx.jpg


Chuck jammed in place before application of gentle persuasion
ZedNPVX.jpg
 
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As an Engineer from Birmingham I always say you can fix anything with a big hammer. If you first hammer wont fix it you just need a bigger hammer.

When I use the term fix i mean if its fixed true and properly ( sometimes you fix it such that it wont work again)

Of cause a hammer is known as a brummagem screwdriver for that reason.
 
Looking to find what chuck tapers Fobco used I found this. Fobco Star chuck removal | Model Engineer
It seems that a lot of Fobco machines have a screwed chuck removal collar. Using a chisel risks damage, even bending the shaft and putting the taper off centre which is why I recommended a pair of wedges before I knew of the collar. Now that the chuck is off measure the taper against this webpage. Machine taper - Wikipedia Fobco seem to have used both Jacobs and Jarno tapers at different times. If you are lucky and its JT3 you can easily get a keyless chuck of the type I suggested. If you have a dial gauge and magnetic holder, check the taper for runout, to make sure the machine is undamaged.
 
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Bit late to this, but I have a Meddings DrillTru, so not dissimilar. Chuck was getting cranky, so replaced it with a Metabo 801 5/8" keyless. That was about 25 yrs ago and has survived daily abuse. The taper fit was not perfect, due to previous change, so I lapped it and put a drop of locktite on it. Not dropped off since.
On the use of hammers... Be very careful! The previous chuck change resulted in a slight bend to the quill shaft. Hardly noticable, but there. I called Meddings for a new one and they said, Sorry, don't have spares. Your drill was bought by your father in June 1960. That impressed me.
 
DownWest said:
Bit late to this, but I have a Meddings DrillTru, so not dissimilar. Chuck was getting cranky, so replaced it with a Metabo 801 5/8" keyless. That was about 25 yrs ago and has survived daily abuse. The taper fit was not perfect, due to previous change, so I lapped it and put a drop of locktite on it. Not dropped off since.
On the use of hammers... Be very careful! The previous chuck change resulted in a slight bend to the quill shaft. Hardly noticable, but there. I called Meddings for a new one and they said, Sorry, don't have spares. Your drill was bought by your father in June 1960. That impressed me.
Click to expand...

I must admit I do abuse my pillar drill. Its a 13mm but I uprated the motor to twice the original and do use reduce shant drills up to 20mm bit size. I alo use it for cutting holes with hole saws in both mild steel and stainless steel may be 6mm thick in stainless. In mild steel much larger.
 
Rogershaw said:
I must admit I do abuse my pillar drill. Its a 13mm but I uprated the motor to twice the original and do use reduce shant drills up to 20mm bit size. I alo use it for cutting holes with hole saws in both mild steel and stainless steel may be 6mm thick in stainless. In mild steel much larger.
Click to expand...
Me too, I upped the motor from 1/3 to 1.2 hp and for the 50 odd 50mm holes in 6mmSS, I piggy backed another motor aft of the existing one to cut the RPM by 1/2 down to the reccomended rpm for the hole saw. Luckily, I was given another DrillTru, ex school, pristine, so good back stop.
 
De-grease your chuck as best you can (dishwashers are good for this if Mrs doesn't mind), and try to remove as much rust as possible by wire brushing.
Then soak the chuck in a 10% solution of molasses for a week or so and it should come out like new.
 
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