Jacobs Chuck on Jet Mini Lathe

Well, sort-of The way I read your description of 1 and 2 below is yet another version of a self-ejector mechanism. Your description suggests that the only part of the tailstock "screw", as you call it, that hits the end of the live center (I'll just use this example from now on to make it easier) is at the center (of whatever diameter) of it's end shank. Is that a correct reading of your comments below? If you have a hole in the bored live center that's bigger than that mechanism, then I can certainly see the live center passing right over it. This, of course, doesn't mean that every live center that has a hole bored through it will not self-eject as George blanketly stated.

What I'm talking about is what's most often found these days and that's where the self-ejector mechanism acts very much the same but makes contact with the outermost ring of the live center end shank. It doesn't matter what size hole is bored (within reason ... you *could* have a 1mm sliver of metal ring and it might slip past the mechanism a little but eventually the taper would catch up to it and hit the mechanism anyway ) into that live center as long as the shank is long enough to reach that self-ejector mechanism when retracting the whole thing.

The essence of it is the same (retracting causes what's inside the morse taper to stop retracting with the rest of the female morse taper) but it's the details that matter most and affects what will and what will not self-eject. Can you provide a picture or drawing of the exact mechanism? I'll do the same of at least one version of self-ejector tailstock mechanism that I've worked with on wood lathes and post it on abpw. Then we can compare.

- Andrew

*****: What ejects the tail center?

"""""": No: What's screwed on the ram

""""": Can't be, Which is in the Barrel.

""""": You are plumb out of the chuck, The ram screws on the barrel!

""""": No V's on that old bowl gouge eh".

""""": I just hope they take precautions to self eject.

""""": Well, what does the hand wheel do?

"""""": You know that dead center has a hollow ring, you dull spur.

(the game was tied til the 17th when the umpire found that *****'s spindle had been plugged with carnauba and """"'s bowl blank had been soaked in LDD. Both turners were ejected along with the revolving center. )

Your correspondent was later arrested for sniffing acetone by a ng moderator. A very sad end to a civil thread with so much promise early on. :( Arch

Fortiter,

Tsk... A good one but nothing about CA glue?

I just posted a picture on ABPW of one type (the most common found on todays' lathes) of tailstock design with the self-ejection feature. I'm just using the common bored-through live center design in these pictures. If needed, I can easily put a Jacobs' Chuck in there or anything else to show what's going on. Also, I can do a drawing of some other tailstock designs (that have the self-eject feature of course) to compare and contrast.

The more I think about George's statement of "You probably have noticed, at least once, that the self-ejecting feature is an extension beyond the ~ 3/8 diameter portion of the #2 taper." the more he's describing a completely different tailstock design. And this statement of his ... "Nope. Think about it. If they're designed to be able to bore through them, they'll lack the self-ejector" really suggests that he's just thinking of that one kind of tailstock self-ejection feature design. He's expecting that "tang" to be there on the end of the male morse taper to hit the center-hitting device in the tailstock to knock it out. In my mind at least, he's confusing that tang as the self-ejection feature in wood lathes.

Hopefully, George will respond in order to clarify what he said and answer my questions. I hate to assume but without a response, I am forced to until then.

Anyway, if anybody has a problem with viewing or understanding the picture, let me know. Also, like I said above, if there's some clarification needed on other tailstock designs and/or different centers (jacobs chuck, etc.) let me know and I'll whip up some pictures.

I have had to get some woodturning video editing done this weekend and earlier this week so I was delayed in getting the picture done and posted. Sorry about that.

- Andrew

I'm describing the taper. Look at the overall length of the same, on the Nova I mentioned, and you'll see that the entire is not long enough to butt against the end as you retract the quill in a lot of tailstocks. Seems like it needs about an extra half inch in length beyond the point at which it is

Yep, I'll grant (for the upteenth time in this thread) you that some tailstocks and devices designed to fit into those tapers just don't go together or are simply poorly designed in the first place. Some of those devices' tapers just aren't long enough to hit the self-ejector in the tailstock. That's why I mentioned to Mike originally.... "That must be a pretty short live center taper! Good point though. How long is that taper you're talking about?".

I'm trying to get the point of the self-ejector mechanism discussion as clear as possible to those turners out there that might be having problems buying and using their centers and tailstocks. Poor and misleading information is not good. I'd hate for someone to read your "Nope. Think about it. If they're designed to be able to bore through them, they'll lack the self-ejector." statement and think that if they buy a live center with a boring hole in it, that their tailstock self-ejector feature will be negated in all cases. I was confused in what you were actually trying to say and wanted clarification so that those that might still be following this thread could have the facts and opinions of those of us posting in it clear. They can make up their own minds, then, as to what they want to buy or try in order to fix their problems.

When you came up with those statements of having the self-ejector mechanism as part of the live center, for example, and of having a bore hole in any live center, again as an example, will negate the self-ejector feature, had me wondering what you were talking about. You still haven't directly referrenced your statements on those points, by the way. Do you still stand behind them? If so, are you willing to clarify those specific statements? Now, you're saying that it's the shorter tapers that might be the problem. Which, of course, is what was being talked about before you started in with these other statements.

I'm always willing and interested in learning and maybe you've run across why those statements are true? Please help us to understand those statements of yours.

Yep. And as I've said before to you in this thread, they are good ways. They're also useful on some lathes' headstocks when a taper fitting device is stuck in there too.

- Andrew

I have dignified your boorish "challenges" and accusations more than enough through my previous answer.

Those who purchase chucks for their tailstock should be aware that if they don't eject, it is not necessarily the fault of the lathe, nor is it reason to panic. The length of the taper may not be sufficient, for which there are two easy workarounds.