Whats The Secret....

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

Sent from my SM-G892A using Tapatalk
 
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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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.
 
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?
 
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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