Help - stuck chuck, stripping gears on Craftsman 6x18

[TN Pat]

Many thanks to everyone for being understanding of my mistake, and all the suggestions. Learned a lot of good stuff outta this one! Quick question - should an impact wrench be unavailable, what's the next best way to remove a chuck?

Trackfodder - Seems to me that, if possible, the best idea is to cut the power before doing any modifications... that's not always possible, but I did make sure my lathe was unplugged!

[Don Young]

It is interesting how many people in other threads have said, 'Lock the back gears and give it a good whack, I have never even heard of anyone damaging the gears that way!'. I confess to locking the back gears, but not to get a stuck chuck loose.

[jhe.1973]

Just a couple of suggestions I have found handy.

A wood block w/notches to fit the inverted vee(s) & a radius cutout to fit the OD of the chuck. Plus a chunk of hex stock welded to a tube to use as a wrench.



The wood block takes the weight while you remove or install the chuck:



And the wrench is grabbed by the full length of the jaws to distribute the force more evenly.



A few years ago the South Bend lathe forum over at the Practical Machinist site had a thread on chuck removal. They may have made it a sticky - not sure. Anyhow, I grabbed this photo from there 'cuz I thought this to be a great idea, should I ever run into a need. It would not stress the back gears at all.



This is for locking the spindle while you use whatever means to loosen the chuck.

[darryl]

Putting it back on- this is my take on it. Clean all the threads, then use a bit of light oil on them and wipe clean. Don't try to remove all the oil, just clean up a bit. If you want to use anti-seize, then wipe the oil away a little more aggressively before applying that. Turn the chuck onto the spindle, and when it comes up close, take up the weight of the chuck in your right hand and turn it the rest of the way on. Don't snap it tight. It should run up crisply and stop, not progressively get tighter, which could be a sign of damaged threads or contamination in the threads. Then block the spindle in whatever way suits (sometimes there's actually a few holes in the spindle to use with a spindle wrench) and use some form of chuck wrench like the guys are talking about. Give it a good tighten, but there's no need to overdo it. I put lug nuts on tighter than I put my chuck on.

If all is well, you should find that the chuck only needs about 1/4 inch or so of extra rotation as measured on the OD to go tight from the point where it first comes up snug.

[Mike279]

Small lathe threaded chucks installed with a snap of the wrist are going to give you a nice tight chuck that will still be easy to remove. Engaging the back gear and using the chuck key to remove it is a tried and true method. Giving the wrench a rap with your hand is all that is needed to release the chuck. If for some reason like the chuck gets rusted on, then by all means do not think the back gear will withstand a beating. These small lathes have small keys and lightweight parts. They can last a lifetime if not abused. A little common sense will go a long ways. Mike

[vpt]

When I install a chuck on my 10" atlas I screw the chuck on till it just about contacts the register, then give it a quick fast twist of the wrist to "snap it on" and thats it.

When I take them off I do use my back gears but I make sure the gears are "loaded" before tapping on the chuck key with my hand. "loading the gears" means turning the spindle/chuck to put pressure on the gears in the way you are going to be loosening the chuck. So when you tap the chuck key the gears don't slap together. This is a drag car trick to not break gears in transmissions or rear ends (and other parts) as well. It is called loading the drivetrain so when you punch the gas peddle there is no shock to the system, everything is already loaded and the ready to just roll out.

[rowbare]

Another thing that apparently works well if you have a bar like this (I have not tried it) is to use an air chisel on the end of the bar.

bob

[shoeboxpaul]

The impact wrench is a great idea. Amazing what those units will break loose.

[TN Pat]

Really neat ideas, guys... I took my chuck back off and reinstalled it with just basically a light wrist-snap, so things are well again... thanks again for the help.

[Thomas Staubo]

When I got my used lathe, it came only with one chuck, which seems to have been stuck in place since 1977.
So to break it loose this method worked very well for me:



( http://bbs.homeshopmachinist.net/threads/24847 )

[andywander]

The OP broke his back gear because he was turning the chuck the wrong way.

Using an impact wrench likely would not have worked, either, in his case.

[Euph0ny]

When I got my used lathe...

That's a nice clean-looking Myford. Can you tell us more about it, and how it ended up in Norway? Mine came to Belgium in my brother's truck

ETA: Apologies - I just followed your link and found the Myford story!

[vpt]

The OP broke his back gear because he was turning the chuck the wrong way.

Using an impact wrench likely would not have worked, either, in his case.

That is true in this case but many cases the chuck will be actually stuck and needs some encouragement to come off.

[Boucher]

The OP broke his back gear because he was turning the chuck the wrong way.

Using an impact wrench likely would not have worked, either, in his case.

Using the impact wrench the gears are not engaged. Turning it the wrong way would tighten the chuck but would not break the gears. Again oil or grease is fundamentally wrong for this application. A good ant-seize prevents over tightening.