Stuck Revolving Centre in Tailstock Spindle

[Wongster]

Hello guys,

Been a while since my last post. I've not been playing for quite some time.

Couple of nights back, I was cleaning up the shop to prepare to start a job. Walked past the lathe and saw some rust between the revolving centre and the tailstock spindle. So I took a tooth brush to brush away the rust on the surface. When trying to eject the centre, I found it stuck tight. So I took the spindle off the tailstock and pour some light oil inside and around the mating portion. Next day, I tried removing it about. No joy. Using a steel rod against the base of the centre, I tried hammering it out. Again, it wouldn't barge. Next came the Proxxon micro-torch on the spindle. Still it refused to give in.



Anything else I can do other than ordering another spindle? I know I should have taken out the centre when not using the lathe but it's too late to cry now....

Appreciate any help.

Wongster

[tackit]

(05-24-2014, 10:21 PM)Wongster Wrote: Hello guys,

Been a while since my last post. I've not been playing for quite some time.

Couple of nights back, I was cleaning up the shop to prepare to start a job. Walked past the lathe and saw some rust between the revolving centre and the tailstock spindle. So I took a tooth brush to brush away the rust on the surface. When trying to eject the centre, I found it stuck tight. So I took the spindle off the tailstock and pour some light oil inside and around the mating portion. Next day, I tried removing it about. No joy. Using a steel rod against the base of the centre, I tried hammering it out. Again, it wouldn't barge. Next came the Proxxon micro-torch on the spindle. Still it refused to give in.


Anything else I can do other than ordering another spindle? I know I should have taken out the centre when not using the lathe but it's too late to cry now....

Appreciate any help.

Wongster

How about drilling a small hole in the spindle so PB Blaster or some other lubricant can get to the center.... then wrap the spline with friction tape to hide the polished metal of the spline.

Cut two pieces of white Oak from a pallet, notch both pieces to hold the spindle in a vise.

Then grind an old pipe wrenches jaws down so they will fit the gap between the two. Next put a cheater on the pipe wrenches handle and give a good pull.

[PixMan]

It's mainly the taper holding it, the rust just adds a little.

I'd make a U-shaped wedge and spacers, insert them between the stuck center and the tailstock spindle, strike sharply. Done.

Use the access to the end of the live center from the threaded end. Get the biggest soft steel rod that fits through the I.D. of the thread and hold it all together while you slam it on a solid, hard surface (anvil?), pin down. The live center should just pop out. When I say biggest rod that'll fit, get a piece of 1018 and turn a diameter to just fit in there and make it just a 1/2" (10-12mm) longer than the depth of hole. The bigger the better, I'd shoot for 3" diameter, 6" long. You need MASS.

BTW, most tailstock spindles have a slot where the tang of a mating Morse taper would land, enabling you to use a drift key to pound loose a stuck taper. After you get that out, lay the center and then a another device with the tang bext to and lay out where the slot on yours should be. Then mill one!

[Mayhem]

See what happens when you do visit us Wongster!

Ken's approach is the one I would use myself. Good luck!

[DaveH]

Hi Wong,
Nice to hear from you
Have a look at this thread -shows Ken's method, Start at post 75
http://madmodder.net/index.php/topic,688...l#msg73843
Let us know how you get on.

DaveH

[Sunset Machine]

With it back in the lathe, did you try ejecting it normally, but leaving the pressure applied overnight? Or leave a wedge in there. Time and penetrating oil often work wonders. I've gotten results with a battery charger & soda too. Another thought to try - make a split bushing with a hole the same size as the spindle. Use one half as an anvil and the other half as a drift, pounding it with a hammer. You'd be momentarily changing the shape of the spindle, maybe enough to break the rust and let the oil work. I'd only try this just before it goes into the trash bin.

[Wongster]

Hello guys,

Thank you so much for all your inputs.

Trying to break the "grip" by knocking didn't work. I inserted a steel rod into the threaded end of the spindle and tried hitting it with a metal hammer hoping to break the "grip". The steel rod ended up with a slight mushroom on the end I hit.

Would the U-Shaped wedge and space work like the above?

There is no slot on the spindle that I can insert a drift key.

I'll read through the post on the link DaveH posted to see if there is something I can do.

I'll try Sunset Machine's suggestion of leaving some pressure overnight. Maybe by the time I wake up the spindle will be pressed out.

Regards,
Wong

[Hopefuldave]

http://madmodder.net/index.php/topic,6881.0.html 4th page shows my method for stuck tapers, required.making a Useful Tool.though - works pretty well and exerts Some Considerable Force.

[PixMan]

(05-25-2014, 11:41 AM)Wongster Wrote: Trying to break the "grip" by knocking didn't work. I inserted a steel rod into the threaded end of the spindle and tried hitting it with a metal hammer hoping to break the "grip". The steel rod ended up with a slight mushroom on the end I hit.

This is why I was trying to explain that you want only a diameter to just barely fit into the thread I.D., but with as much mass as possible behind it. A sharp impact with mass bigger than the stuck live center is what you need...and a 10lb (5kg) sledge hammer hitting it.

[Wongster]

Noted, Pixman.

I'll look for a big enough rod to do it.

Thank you.

Wong