Removing the live center from the tailstock

[unidave]

I can't believe I can't figure this out.
My lathe has a live center in the tailstock. How do I remove it?
If I crank the wheel back it bottoms out and doesn't pop the center out. When I use the small brass slidehammer, the center pin pops out but leaves the center in place.
I bought the Oneway center kit with the accessories thinking I would solve the problem but it's center pin pops out too.

What am I missing? I currently place a wrench handle between the back of the center and the casting of the tail stock and "ram" the crankwheel back until the center pops out. Is this normal?

--
Dave

 

[mkart]

live center

I found that some live centers are short and do not eject when the tailstock is withdrawn all the way. For mine I simply glued a small block on the back of the center so it was 3/8" longer. Problem solved. I do not however have a hollow tailstock or the fancy live center systems you mention. Anyway, compare the taper length to another and see if you have a longer one that will eject. If so maybe you could turn a removable stub to insert into the end of your taper that is too short. You would remove it when you need to pop out the point.
mkart

 

[pfduffy]

Live center stuck

Are you certain you have turned the handle hard enough to break the live center free of the friction???? In my PM it takes a pretty tough backward yank of the wheel to get it free. (one of these days i should get a cleaner for the tailstock socket!) Phil

 

[Bill Boehme]

Here is how to do it:

1. Crank the tailstock center to its fullest extended position.
2. Insert the knockout bar -- it will have a little side-to-side play so angle it as much as you can so that it catches the back edge of the live center rather than passing through the hole in the middle.
3. Draw the bar back about eight inches or so and then then give it a very sharp forward slam while keeping it angled to catch the edge of the live center.
4. It should pop right out -- hopefully.

There are some live centers that have short Morse tapers and therefore can't be ejected by cranking the center into the fully retracted position. I have heard that there are some lathes that don't eject the tailstock centers by cranking them to the retracted position.

Bill

 

[Mark Mandell]

NOT Normal

This almost always happens because the morse taper surfaces on the center and the quill have grit or galls and scratches. These two metal surfaces must fit precisely with each other, and imperfections will tend to lock them together. To do well, they they must be free of dirt and grit. You therefore need to inspect the live center's male taper's surface for damage and bumps and gentle remove them with a fine file. Do not use abrasives because the granules fracture in use and embed themselves in the surface of the metal leading to more problems and damage.

When you have the taper on your center cleaned and smooth, you need to inspect the inside surface of the quill [ram]. Do this by shining a flashlight from the crank-wheel end and looking at the tapered surface. Chances are, you will see the scratches and bumps that are serving to lock the two pieces together. There are two ways to safely "clean" the defects from the female taper. 1 is with a fine rat-tail or half-round file used very carefully to take off just the bumps; danger here is to file the taper out of round which will ruin it. The best way, however, is to use a morse taper hand reamer. We had a thread on this here recently so just do a search. While I know others that use sand paper for this, I strongly disagree; especially if you want your centers to continue to line up and release properly.

While you're at it, you'd best check your headstock taper and drive center taper surfaces, and remember that you should, every time, carefuly wipe both surfaces clean in both tapers before inserting the accessories.

Note that you may be able to borrow a taper hand reamer to fit your lathe from a friendly local machine shop. Makes things a whole lot more precise.

M

 

[MichaelMouse]

Before you do anything drastic and ill-advised, does your taper have an extra stepped-down area behind the main taper for self-ejection? Some, like the Nova, do not, because they're designed hollow to use a knockout bar to release the various centers. I found it necessary to do the same as you are doing, putting something between the edge of the center and the tailstock to pull against and eject the taper.

Had the machinist up the way make an ejection extension, but found it was more trouble than it was worth, because it had to be loose enough to remove for my knockout bar, but tight enough not to be left rattling around in the nether regions of the female taper.

So first determine if the beast is long enough. Comparing to your spur taper should do it. Diameter at given length and overall length. If it's short, it's short, and youve already found a way to work around.

 

[Jim Carroll]

Check the differance with the handwheel all the way back and then put your live centre in and see if it comes all the way back.

It could be that your tailstock does not have the self ejecting part in it so you require a knock out bar.

The live centre kits do not have the extra length required for the self ejecting tailstocks .

Get your self a larger diameter knock out bar that suits the diameter of the end of your live centre. Most knock out bars are only made to knock out solid end live centres and generally go through the live centre and knock out the centre pin, which is handy when you want to change the pin centres.

If you are going to use your existing bar on the angle as indicated earlier make sure the bar has a square edge as most bars a slightly rounded and it will not catch the edge and just run up the centre. Just hold the bar against the centre and give it a good hit with a hammer it should jar out for you or it may take a couple of taps to get it out.

All depends if you seated the centre right before puting it against the timber or have ben using the tailstock as a ram and pushing in very hard.

 

[Jack Savona]

Have you Googled your make and model to see if it has an auto-eject taper in the tailstock?

Jack

 

[Brian Hahn]

I have two lathes that do not have self-ejecting tail stocks. I made a "plug" for the end of my live center from a short bolt with the head ground down until it was smaller than the taper. A small rubber band wrapped around the threads makes it a tight fit and keeps it from scratching the tail stock's taper. This works well, but I'll occasionally forget to put the plug into the live center. I eventually made a U-shaped piece of wood that slips over the tail stock quill and pops the center out when the tailstock is completely withdrawn.

 

[john lucas]

I have a Nova live center which has a hole all the way through. My lathe won't eject the center and a Knockout bar slides through the other hole just like yours. I crank the quil feed out far enough to fit my skew (or other flat metal) in between the tailstock and the live center. then just crank the handle back and it will eject the live center. I made a little metal ring that fits between the live center and tailstock so that when I crank the quil feed back it ejects the center but I forget to put it on about half the time.

 

[unidave]

Great ideas

Thanks for the great ideas. My new oneway live center kit is now the 3rd center I own. Delta sent me a new one when I told them the center pin "broke" I didn't know at that time it was removable. /oops/
I'm going to try all these ideas though and post my results. The lathe is a Delta 46-755x and I've felt its been a really great machine, but both centers (drive and tail) seem a little below par. I'm REALLY happy with the Oneway live center kit but haven't seen anything for a better quality drive center. Any ideas?
That taper reamer sounds like a good idea. It'll work in the drillpress too.
/end of ramble/

Dave

 

[C Edward Moore]

Stebcenters

Dave,

I recommend the Stebcenter for a drivecenter and the revolving Stebcenter for the tailcenter. You will find both at Packard or Craft Supply USA.

The tailcenter above was too short to eject from my Oneway 1018, so I epoxied a small hexbolt in the end and ground off the corners. It works beautifully now.

Now for a few words about the Stebcenter. The center pin is spring-loaded and as pressure is applied the pin retracts, allowing the small teeth around the rim to engage the wood. These centers are especialy good for spindle work. They are used by production turners because if you retract the tailstock quill while the lathe is running the teeth disengage and you can remove the piece from the lathe and insert a new one without stopping the lathe.

Stebcenters are particularly good when a piece is removed from the lathe and is returned to the lathe later. Things line up extremely well. I recommend these centers and so do some better turners than I am.

 

[C Edward Moore]

Stebcenters II

I think I misspoke in the above post. I did not use epoxy, but I used thick CA glue to keep the bolt in place. This way, if I need to eject the pin from the tailcenter I can simply apply some heat to the bolthead and extract the bolt from the Morse taper. Then the pin is accessible and can be tapped out.

Dave, for general use you should find the Oneway center to be quite good.

 

[Mark Mandell]

Thanks for the great ideas. My new oneway live center kit is now the 3rd center I own. Delta sent me a new one when I told them the center pin "broke" I didn't know at that time it was removable. /oops/
I'm going to try all these ideas though and post my results. The lathe is a Delta 46-755x and I've felt its been a really great machine, but both centers (drive and tail) seem a little below par. I'm REALLY happy with the Oneway live center kit but haven't seen anything for a better quality drive center. Any ideas?
That taper reamer sounds like a good idea. It'll work in the drillpress too.
/end of ramble/

Dave

Dave,

Don't get jiggy with a reamer! It's NOT for frequent use, and can wreck your spindle/quill if used improperly. At the risk of repeating myself, I want to point out that the hand reamer is only for repair of a damaged taper. To keep your tapers clean, use a cleaner such as Packard sells [ http://www.packardwoodworks.com/Mer...=117902&Category_Code=lathes-acc-tapacc-tapmt ].

I was a little surprised to hear which lathe you have; I would expect a $2,000 lathe to have a self-ejecting tailstock, but yours doesn't. While your machine is supplied with a knockout bar for removing the centers, that block idea for the tailstock is a good one to avoid scoring the quill taper's surface by pounding a steel rod through there trying to get a center to release. I did the same kind of thing on my Stubby's headstock when I use a small drive center. My lathe is situated and set up such that I can't use a knockout bar to eject the drive center. I therefore have a 1-1/4" x 8 cap nut with a 3/4" hole drilled in the center. I thread it on and then insert the drive center. When I'm finished with the center, I simply spin the nut back out and it removes the center as well.

Good luck

Mark

 

[Captain Eddie]

make a jig

I have a woodfast without the little gizmo to kick out the live center. Our Club's Delta is the same way. I made a 1/2" knockout bar that doesn't go through the tailstock, but over it. I butt one end of the bar against the cast end of the tailstock and the other against the edge of the revolving center. Then crank the quill back until it pushes out the live center. No hammer, no fuss, no muss. It doesn't hurt to polish the live center with steel wool to clean it up, just don't put any oil, teflon, wax or anything else on it. They all add a film and that, with heat, creates GLUE. I clean the inside of the taper with a cleaner stick and some "Goog-OFF". My problem with this situation went away in one hour.

 

[John Taylor]

Add a Nut

Why not add a hex nut on the end of the taper? This would solve the ejection problem and would still allow the center pin to be removed. If the nole in the nut is a problem then screw in a set screw or short bolt.

John Taylor

P I think I'll try this today.