Turning off a Stuck Backplate

[woodchucker]

so I'll offer the solution that allows you to use the backer plate as a nose protector, I was hoping you would try the methods outline earlier. but I feel this is worth saying.
Trim the plate down to about an inch larger than the spindle.
Now you can get a parting blade behind it easily.
use your parting blade to relief cut the back of the plate near the register, you only have to get near the register, and only up to the spindle even 20 thou short of the spindle.
That should remove the pressure that is holding it on. I had this problem with my tailstock, the screw was jammed in, and people were telling me to put a monkey wrench on the quill, and the screw (both would ruin the pieces so what's the point). Someone smart chimed in to just relieve the back of the tailstock quill and it would remove the pressure. BINGO.

I don't think your problem is a chip. I'm betting its totally jammed on and the register is putting so much pressure on the threads they are locked.
I have been there when the chuck was not fully on and I turned the lathe on, jamming it to that same point.

That's why I offered my original post. BTW putting a hex in a 3 jaw and wrenching the hex will not damage the chuck, it's what it's made for. Putting a wrench on the jaw can in fact damage the chuck. So go get a Big joiner bolt for hanging all thread (easy hex) or if you have a hex piece .. and get this done. I am sure the weight will work with less effort, But do jam the bull gear with a wedge, don't break a tooth with the back gears.

 

[G-ManBart]

I have had a chuck that was so stuck nothing would work....every method mentioned was tried and after a couple of weeks I bit the bullet, bought a $20 3D printed bull gear wedge and the chuck came off. I had removed the chuck from the backing plate, and bolted a cheater pipe (maybe 36" long) to the backing plate. I installed the wedge, lifted myself up with the pipe and pop, the chuck came undone.

If you have a lathe with a threaded spindle, spend the $10-20 to get one of these wedge locks!!!!!

SPL South Bend 9A Spindle Lock Wedge Block Used To Remove Tight Chucks | eBay

The chuck is removed by placing a wrench on a jaw and turning it off, or your preferred way. The Spindle Lock must be slid in from the gear face. With slight pressure, the lock will slip in place. The spindle is then rotated allowing the block to wedge in place.

www.ebay.com

 

[Shiseiji]

Just a comment for a hex. I used a cheap hex shaft 3/4" cold chisel. This provided full contact with the jaws and then an impact socket & wrench.

 

[Shiseiji]

This is a resource I too often forget about: https://www.lathes.co.uk/stuck-chuck/ Tony provides insight on holding the spindle.

 

[rwm]

That article describes "Frostbite" as something plumbers use. I have used dry ice with good success. I cannot find a reference to this in the US? What is it?

 

[David2011]

Something I’ve learned in disassembling old large frozen parts on the big deck guns of the Battleship Texas is that big heavy pressure is usually much more effective than an impact wrench. The instantaneous hits just don’t do the same thing as steady big pressure from a cheater pipe. Sometimes, as previously mentioned, it’s effective to load up the tool and let it sit. If you get lucky it will pop free from relentless pressure.

 

[Pevehouse]

Hi and welcome,

Are they still running the kart track at Ravenna? I always meant to get down there when I lived in Michigan but never made it.

When you say you've tried all methods for getting this off how long have you been working at it? My one experience with a stuck chuck it took weeks of patient effort but finally got it loose. It's worth taking more time if you've only been working at it a few days since it appears undamaged in your photos.

I guess if I were going to try and turn that off I would just cut it down until I only had maybe 1/2" left then cut a slot perpendicular to the spindle as close as I dared. With that, a few blows with a cold chisel should break the cast iron and get if off.

But, I'd really try a little harder before giving up. I'm sure someone who's actually had to do what you suggest will come along with better advice than me soon.

John

He could cut a slot on the outer diameter as well and use the coal chisel method. Just thinking out load. I’m with you, I would try other options first

 

[Pevehouse]

I presume heat from a propane torch has been tried- if not I would try it, with a long lever (wood or metal) on the plate

Was just about to say that a little heat can go a long way. At the shop that is usually our last resort but it always works without fail,lol

 

[rwm]

Any success on this?

 

[mickri]

I have one of the bull gear locks too. Very effective for removing stuck chucks.