# Whats The Secret....



## Stump Fabrication (Aug 15, 2015)

To getting the chuck to come off of my 10f TH54? Ive got the back gear engaged with the pin lock, but not sure of:

1. How much force it takes to normally remove the chuck
2. What the best way to "grab" the chuck while removing
3. Left hand thread or right hand thread?

Just looking for some tips/tricks. No idea how long it been on there.


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## Stump Fabrication (Aug 15, 2015)

Never mind....I got it off. Luckily someone before me used a little oil on the threads and there wasnt much effort involved in getting it off.


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## kd4gij (Aug 15, 2015)

Glad you got it off, but using the back gears and pin to lock the spindle is a bad habit to get into as it van damage the pin and back gears. Better to use a piece of wood to hold the bull gear. Or chuck a piece of 2" x 2" x12"or so in the chuck so it is hanging out far enough to hit the bead and rotate the spindle by hand and bump it loose.


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## wa5cab (Aug 16, 2015)

Sorry, but I disagree and so did Atlas.  The MOLO lists locking the spindle by engaging back gear without pulling the direct drive pin as the standard way to lock the spindle for removing a chuck.  I've used this method for nearly 35 years.  I rotate the chuck until the key socket is between 12:00 and 1:00 o'clock, engage back gear, put the chuck key in the socket, grab it with both hands and pull smartly.

However, if I had just bought a lathe and it had a chuck on the spindle that I had never removed before, I would first spray the back of the chuck where the spindle screws into it with penetrating oil (Kroil being preferred) and let it sit for at least an hour.  Then I would more than likely rotate the chuck until it had one jaw at 12:00 (3-jaw) or two at 10:30 and 1:30 (4-jaw and engage back gear.  Then I would grab a piece of 2x4 about 24" long in the chuck jaws and rap on the end of it with a large shop hammer.


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## hermetic (Aug 16, 2015)

Don't use the chuck key (though everybody does!) because on some chucks the socket for the chuck key is rather thin at the corners, and I have seen more than one split at the corners by doing this. My preferred method is a large adjustable spanner on one of the jaws, A La Doubleboost!


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## kd4gij (Aug 16, 2015)

Well I have read a few times where things broke trying to remove a stubborn using that method.


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## mzayd3 (Aug 16, 2015)

I usually put a crescent wrench on one of the jaws


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## 38Bill (Aug 16, 2015)

I use a 1/4" socket wrench extension. Its long enough to get some good leverage and it fits my chuck socket very well.


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## Round in circles (Aug 17, 2015)

This thread is very interesting  interesting .
I'd always been taught to pop the chuck key in and with it at  9 o'clock give it a quick tap with a hide hammer ..I've got posh these days and have used a small rubber camping ten peg hammer for the last year .  I've not locked the spindle but have put it to drive without having started the motor ..the resistance to movement of the belt , pulley & motor appears to be a sufficient brake to let me crack the lock up with the a gentle tap .

  I think I'll be using the back gear lock method  along with a  15 inch long 3/4 inch square mild steel bar across open jaws from now on ,  as well as the rubber hammer if needed , for I'd be beside myself if I wrecked a 3 or 4 jaw chuck on my beastie .


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## Andre (Aug 17, 2015)

My chuck was very tight when I got my lathe, I was wondering if I ever could get it off. A 12" crescent wrench and a long pipe helped out. Beautiful lathe, also!


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## wa5cab (Aug 18, 2015)

Of course everyone is free to remove the chuck whichever way they want to.  But the only two circumstances where I might resort to any method other than locking the spindle with the back gears and pulling on the chuck key by hand would be (1) a new to me lathe that arrived with a chuck on the spindle and two tries the standard way didn't break it loose and (2) if I had ever been dumb enough to run the carriage into the chuck.  Any chuck so fragile that it might be damaged while removing it this way is too fragile to live, anyway.


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## ogberi (Aug 18, 2015)

I usually put the lathe in back gear and use a piece of 1' long 1/2" bar through the chuuck jaws.  A thump with the heel of my hand is usually enough to get it loose.   When I install a chuck I engage the belt with the motor off & thread the chuck on.  I give it a spin for the last 1/4", so it thumps solidly, but not too tightly, home.   I always oil the threads with straight 30wt non detergent oil before installing a chuck, faceplate, or thread protector.


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## wa5cab (Aug 18, 2015)

OK.  That all sounds reasonable.


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## Stump Fabrication (Aug 18, 2015)

What I ended up doing was basically what some suggested. I locked the back gear, and used a 1" wooden down between the jaws as a pull handle. it came off quite easily...way easier than expected.


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## Round in circles (Aug 18, 2015)

Robert I have had to resort to using different methods .. This spinal disability & subsequent operations  has left me even struggling to un zip a banana


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## wa5cab (Aug 18, 2015)

OK.  That's certainly understandable.


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## chips&more (Aug 18, 2015)

I just chimed in on this thread, WOW. I do not have a threaded spindle lathe. But, if I caught anyone putting a crescent wrench or similar on one of my chuck jaws. I would first need to pick myself up off of the floor from fainting. Then it would get really ugly…Dave


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## timmeh (Aug 22, 2015)

Back in high school our metal shop had hercus lathes, shop teachers instructions were, "in back gear(lock pin out), block of timber on rear of bed that reaches centre height, using countershaft pulley(large outer one), roll by (one)hand firmly until jaw contacts timber(two trys only). Should be sufficient. If not, lock pin, pipe/bar suitably sized so as not to bend approx 2' long, through jaws perpendicular to spindle, lightly tighten jaws, ease pressure on until thread loosens(no hammers allowed, and no gymnastics practice on the pipe/bar)." After that we had to call him.
If all that fails, then the usual, CRC/WD40 and the like, then some heat.
Took me about a week to get a chuck adaptor off my grandfathers old lathe, that thing had been stuck on there about 50 odd yrs or more by all accounts. Other than that, the only other thing that might cause a real problem is if your thead "picks up" whether due to rust or grit. Then the real "fun" begins.


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## hermetic (Aug 25, 2015)

chips&more said:


> I just chimed in on this thread, WOW. I do not have a threaded spindle lathe. But, if I caught anyone putting a crescent wrench or similar on one of my chuck jaws. I would first need to pick myself up off of the floor from fainting. Then it would get really ugly…Dave



I think we may be confusing tools here, I do not know if an adjustable spanner is the same as a crescent wrench in the US. The adjustable spanner is fitted to the side (unused) part of the jaws, and pulled firmly, no hammers or cheater tubes. With a steel jaw and a cast chuck body in compression I fail to see how you could do any damage to either chuck or jaw unless you are the incredible hulk. Please explain how this action could do damage.


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## JimDawson (Aug 25, 2015)

hermetic said:


> I do not know if an adjustable spanner is the same as a crescent wrench in the US.



Yup, same thing.


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## T Bredehoft (Aug 25, 2015)

At one time "Crescent" was the most sought after brand of adjustable spanner.


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## oldschoolcane (Apr 30, 2021)

It appears to me that I have a 3 jaw chuck on my Atlas 10 that I can't seem to remove? This is a chuck that came with the machine so I don't know whats been done to it before I got the machine. I have consulted MOLO but still don't know exactly what to do to correct this.


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## Grinderman (Apr 30, 2021)

I use this little device if I need to lock the spindle. It engages with 12 teeth on the bull gear and then wedges against the casting to lock the spindle. A guy was selling these on ebay awhile back, not sure if he still does.


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## larry4406 (May 1, 2021)

Found the back gear lock








						Atlas Craftsman 10 & 12" Spindle Lock Block by CRAFTED REMOVE STUCK CHUCKS  | eBay
					

Engages 13 teeth of the bull gear all at once. Developed to remove a chuck that got stuck for no apparent reason on my regularly used lathe. I had my 18" Adjustable wrench on the jaw as well as 36" long pipe.



					www.ebay.com


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## oldschoolcane (May 1, 2021)

That is a decent tool, I had no idea something that specific was available! I have tried engaging the back gear but as I apply pressure to break the chuck free the back gear lever loosens and moves out of place? Plus, I am afraid to possibly damage the gears. So I haven't done anymore until I can find a better way. I don't think this chuck has ever been off this lathe. Once I have the bull gear engaged, what is the best way to apply pressure to the chuck?


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## Weldingrod1 (May 1, 2021)

locking the back gear is fraught with peril :-(
Very easy to break a tooth.
Of course, the next weak link is the key between the bull gear and the pindle... 

I made my own version of that tool at least a decade back.

Apply penetrating oil and let it work.
Order the lock widget.
Install lock
Heat chuck.
Wipe inside of spindle with cool liquid.
Unscrew

Clean, clean, clean all the chuck and spindle threads afterwards.

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## JPMacG (May 1, 2021)

I have the spindle lock that Grinderman and larry4406 mentioned.  It fits the bull gear like a glove and works very well.  I have not tried it on a badly stuck chuck - so I can't say how well it would hold up.


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## wa5cab (May 2, 2021)

Note that if you don't pull out the Direct Drive Pin (in the side of the bull gear) but engage the back gears, this locks the spindle and is the factory recommended way to routinely remove a chuck.  But it is NOT the way to remove a stuck chuck, as several people have already said.  The back gear locking device being sold on eBay, however, is safe to use as it engages several teeth at once.  and does not depend upon the direct drive pin and the rest of the back gears to lock the spindle.  Basically, if you break off several teeth with it, the gear was scrap anyway.

To use it to remove a stuck chuck, first apply penetrating oil by whatever means to the chuck and spindle threads and let sit for a few hours to a day to give the penentrant time to work.  Obtain a short (around 6") length of hex stock (for a 3-jaw or 6-jaw) or square stock (for a 4-jaw) that will just fit through the hole in the center of the chuck.  Insert the stock through the jaws and deeply enough into the chuck to engage the jaws fully.  Tighten the chuck jaws onto the stock.  Rotate the spindle until you can fit a hex wrench or key into the set screw that locks the bull gear to the Woodruff key in the spindle and loosen the screw.  Install the bull gear lock and turn the stock in the direction to loosen the chuck.  While holding tension on the stock, re-tighten the screw as you normally would.  At this point, what you do next depends upon what wrench you have to break the chuck loose with and how you plan to turn it.  My preference would be a 3/4" square-drive socket, breaker bar and cheater pipe.  And the above assumes that the lathe is securely anchored to the stand and the stand anchored to the floor.


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## larry4406 (May 3, 2021)

wa5cab - what is the purpose of loosening the woodruff key set screw to then retighten it?

Also, looking at the chuck from the tailstock, does the chuck turn counterclockwise or clockwise to loosen?


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## Grinderman (May 3, 2021)

Wondered the same thing about the set screw. Chuck turns counter clockwise to loosen. Seems like trying to loosen a stuck chuck with something tightened into the jaws the normal way wouldn't give you much leverage.


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## wa5cab (May 4, 2021)

Yes, CCW.

If you don't have enough leverage, get a larger wrench and/or a longer cheater pipe.  Seriously, if the chuck is small enough and isn't a drill chuck, you can try using a strap wrench around the chuck body, if you have one large enough and sturdy enough.  The reason for limiting the size of the square or hex stock to what will just fit through the chuck body is that part of the jaw is always "down inside" the chuck body.  With square stock and maybe with hex, you can turn part of the corners off of the part down inside the chuck in order to have a larger socket or wrench on it.

The reason for suggesting the set screw loosening and re-tightening step is that there is always a little play or clearance between the key and the slot in the bull gear.  The suggested procedure ensures that you start off with the key firmly against the side of the slot that you are going to be pulling against.


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## markba633csi (May 4, 2021)

Interesting thread- I guess there are folks who use the same chuck forever, for every job, hence the 50 year stuck.  
Probably a good thing to add to anyone's used lathe evaluation:  does the chuck come off easily? 
-Mark


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