Removing a 3 jaw chuck off a lathe

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Grizzly Adams

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So, I've been playing around with my 3 jaw chuck for a while and it's time to move on. Looking for hints to remove the chuck, no spindle lock on the lathe [Liang Dei 1236] threaded chuck. Putting a bar in the chuck and reversing it doesn't seem like a good ides, I've tried a strap wrench , but can't seem to get a grip. Thanks

Grizz
 
Clamp a bar in the chuck to put take up slack in the jaws, then place a large wrench on one jaw and rap on it with a dead blow. Best if you can do it with the machine in neutral to avoid beating on the gear train. Work for me on my southbend and comes off fairly easily.
 
Can you post a pic. of the chuck. It does sound like it has cam locks holding it in. If it's a cam lock it will have what looks like a plce to stick a chuck key in.
 
I Google the lathe it says you have cam locks. See #3

Features:
1.Bed is made of high tensile cast iron FC25.
2.Hardened and ground bedways.
3.D1-4 camlock spindle.
4.Metric or imperial specification depend on customer’s instruction.
 
Set the lathe spindle to it"s lowest speed. This should keep it from turning. Open the jaws on the chuck half way and place the end of a 3/4 to 1 inch bar of steel across two of the jaws. Give the other end of the steel bar a good wack. It should come loose if the chuck is threaded on.
Please post a picture of the chuck mounted on the spindle. I do not think any of the newer Chinese lathe have thread on chucks. It would come off if the spindle was revered.
 
One of my lathes is setup like that and I put a bar in the open jaws put it in back gear and take the slack out of the gears then give it some blows with the palm of my hand it comes off easily but I change it regularly so it aint stuck.

I tried taking one off a south bend once it never came off so needless to say I didn't buy that one , they can be tight but once removed it will be easier next time.

If it won't come off like that you're going to have to figure out a way to hold the rear of the spindle and use a longer bar good luck
 
I put a piece of wood on the ways to protect them in case I drop the chuck. Use a 3/8 ratchet with a short extension to back off the cams. Then tap the chuck with a mallet to brake the bond. The oil sometimes make the chuck stuck to the head stock.
 
If it has clam locks. You will see 3 or 6 holes that take the same chuck key as the lathe chuck around the spindle behind the chuck. Place the key into each cam lock hole and turn counter clock wise to loosing the cam lock. The lathe chuck will slide forward was the pin come out of the hole.
 
remp49 said:
Set the lathe spindle to it"s lowest speed. This should keep it from turning. Open the jaws on the chuck half way and place the end of a 3/4 to 1 inch bar of steel across two of the jaws. Give the other end of the steel bar a good wack. It should come loose if the chuck is threaded on.
Click to expand...

This is how to remove a threaded on chuck. I do it daily, my 4 jaw and 3 jaw get a good workout. They remove very easily.

Open your jaws like this so the 16 inch bar isn't damaging anything... and tap the end with a rubber mallet...

ou7LK0e.jpg
 
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Does the lathe have a spindle locking pin? If so, lock the spindle and apply torque with a strap wrench or an end-on piece of 2 x 4 against one of the chuck jaws, smacked with a hammer. Sharp hit, you just need to jar it off it's seated position.

Don't lock the spindle using the gears, if it is a gear head. Shearing a spindle lock pin is a minor hassle, shearing gear teeth is a major headache.

If no pin to lock, have you access to the belt pulleys on the head spindle? A strap wrench made of a chunk of wood and a section of an old vee belt will work to apply the lock down, while either jarring it loose or applying torque with a strap wrench around the chuck. I have also resorted to a hook spanner in to the key hole on the chuck, or a large adjustable wrench gripping the chuck jaw.

Does the lathe reverse? Run it in reverse and slide a end grain block of wood in between the bed and the chuck jaw. Be ready on the power, and ready to catch the chuck.

Some times something as simple as setting a heat lamp to shine on the chuck for a bit will soften up the dried oil that may well be causing the issues with getting that initial movement. A heat gun works too, steer clear of hair dryers, the long run time and restricted flow across the heat elements tends to fry the Thermal Fuse, and they are a hassle to change out.
 
I had a similar problem with my lathe. I ended up having to remove the entire spindle from the headstock with the chuck still attached. I put the spindle in some round jaws in my vise and the chuck came off pretty easy.
 
guntech said:
This is how to remove a threaded on chuck. I do it daily, my 4 jaw and 3 jaw get a good workout. They remove very easily.

Open your jaws like this so the 16 inch bar isn't damaging anything... and tap the end with a rubber mallet...

ou7LK0e.jpg
Click to expand...

Gonna try this. Thanks

Grizz
 
Power Pill said:
I had a similar problem with my lathe. I ended up having to remove the entire spindle from the headstock with the chuck still attached. I put the spindle in some round jaws in my vise and the chuck came off pretty easy.
Click to expand...

I think every budding machinist has heard the story of the newby that spun the chuck onto a lathe using the lathe power and a fast spindle speed....the only way it could be removed was to machine the chuck off the spindle threads. LOL
 
fingers284 said:
I think every budding machinist has heard the story of the newby that spun the chuck onto a lathe using the lathe power and a fast spindle speed....the only way it could be removed was to machine the chuck off the spindle threads. LOL
Click to expand...

lets hope this is not the case. That would be a very expensive lesson. Like I always say, "an education costs money, some of us have just have to spend more"
 
if its threaded use the bar as pictured, I use a aluminum bar so not to bruise the jaws, set lathe on low speed first, do not use any spindle lock as you have a chance of shearing the lock pin.

if its a D 14 camlock like the google says, take a look behind the chuck, is there 3 square cams that look like the square on the chuck? if it does you need to rotate the square to unlock the chuck and it will fall off, as stated a couple pictures of both the front of the chuck and one from the side showing the chuck mated to the spindle nose

if its been on some time or used in reverse it is likely tightened and will need to be hit with a dead blow on the bar to crack it, assuming its a screw on
 
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laurencen said:
if its threaded use the bar as pictured, I use a aluminum bar so not to bruise the jaws, set lathe on low speed first, do not use any spindle lock as you have a chance of shearing the lock pin.

if its a D 14 camlock take a look behind the chuck, is there 3 square cams that look like the square on the chuck? if it does you need to rotate the square to unlock the chuck and it will fall off, as stated a couple pictures of both the front of the chuck and one from the side showing the chuck mated to the spindle nose

if its been on some time or used in reverse it is likely tightened and will need to be hit with a dead blow on the bar to crack it, assuming its a screw on
Click to expand...

The chuck jaws and chuck are harder than a soft steel bar, an aluminum bar isn't required.

He stated he threaded the chuck on. it is not a cam lock. Hopefully when he threaded it on he did not do so using power and fast rpm.

When I thread my chuck on I do so by hand and only in the last 5 or 10 degrees give it a little snap with my hand to snap it tight... If he powered his chuck tight he will have to use a 2 pound hammer and several hits to get it loose.
 
guntech said:
The chuck jaws and chuck are harder than a soft steel bar, an aluminum bar isn't required.

He stated he threaded the chuck on. it is not a cam lock. Hopefully when he threaded it on he did not do so using power and fast rpm.

When I thread my chuck on I do so by hand and only in the last 5 or 10 degrees give it a little snap with my hand to snap it tight... If he powered his chuck tight he will have to use a 2 pound hammer and several hits to get it loose.
Click to expand...

years ago I saw a hobby machinist use the turn it on 2 threads and turn the lathe on to tighten, yes it worked but when he stopped the lathe it un threaded off the nose and proceeded to do carnage in his garage

The jaws are hardened compared to say hot rolled steel but it will put a mark on the jaws, its not how hard they are but the level of deformation they can stand
 
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