9" standard modern utilathe nose spindle thread orientation.

[YYCHM]

What became of your stuck chuck? Get her off?

 

[PowderPig]

No, it's still on the lathe. I had some projects to finish up on the lathe and I don't have another chuck. I am looking to purchase a 6" 4 jaw chuck and then I will cut the seized backing plate off of the nose spindle.

 

[TorontoBuilder]

No, it's still on the lathe. I had some projects to finish up on the lathe and I don't have another chuck. I am looking to purchase a 6" 4 jaw chuck and then I will cut the seized backing plate off of the nose spindle.

I know you have a plan already, but if anyone else has this issue, and wants a solution that does not risk breaking teeth of gears, try machining a taper lock fitting that inserts into the rear of the spindle... with a center rod, and two matching cone tapers that are split and screws used to draw them together and wedge into the spindle bore.

The center rod is cut square to fit a impact hammer. Then you wedge a long bar in between the chuck jaws so that it prevents rotation of the chuck. Pad the bar where it contacts the ways with leather.

Now you can put rotational impact on the spindle while the mass of the chuck is held firm... this should be easier on the bearings and seals.

 

[YYCHM]

What became of your stuck chuck? Get her off?

 

[Dabbler]

There's one other method that I have heard of, but not tried is to make up a fixture that you can mount as long a piece of pipe you can ie: 8-10 feet if possible, engage the back gears to lock up the headstock

Please, no. absolutely not. The result will be a broken tooth on the back gear.

what I call the 1000 taps. Like death by 1000 cuts. No big hammer blows, just tons of little ones,

Oh yes.

This is what worked for me with a SB 9c with a rusted on chuck. Lubrication and lots of penetrating oil ... Remove the chuck from the backing plate - it is only in the way. Bolt a piece of flat bar on the backing plate with about 1" extra to tap with.

USE THE SMALLEST HAMMER YOU OWN - but not more than 3 or 4 ounces in any event.

Disconnect all belts and gears so the spindle is free turning.

every time you pass the lathe give it 25 or 30 taps. -- sharp ones firm ones, but not big ones. After 1000 taps or so, feel free to give a few (5 or so) taps in the tightening direction, then 1000 taps unscrew, 5 taps retighten. You keep doing this until the things gives way, which it will, eventually.

The alternative is to cover everything in plastic - I mean EVERYTHING, and slit the backing plate a zip disk. Notice I did NOT say "cut it off". it is very easy to damage the threads: Once you have a little material holding the backing plate on, use a wedge to slowly (and gently) open the cut. Then resume the light tapping: either it will loosen, or the backing plate will crack open.

In my case with the 9c, the rust was pulverized by the light taps and it came off. My friend Bert removed a backing plate by splitting the iron backing plate, so I know it works too.

 

[140mower]

Please, no. absolutely not. The result will be a broken tooth on the back gear.

? Nope..... It won't, no shock, no hitting....... heat and patience with a little oil. Of course you need to have the space where it won't be in the way...