Jacobs Chuck on Jet Mini Lathe

"AWood70928" wrote: (clip) how, do

Does your Jacobs chuck have a Morse taper on it? That's what you need. Just slip it into the tailstock the same way you insert your live center, or any other gadget.

You should be able to purchase a screw in taper shaft that would match a Jacobs or other chuck. Take your live center to any regular machine shop and they can identify the taper No. in order that the one you buy will fit in your tailstock. They may even cite you a source.

The piece you remove from the tailstock with the live center on it should be a tapered piece (I'll call it a "morse taper" within the text of this post so the purists don't beat me to death with the proper term). Sears (for example) sells a threaded morse taper that you can install a Jacobs chuck on, then slide back into the tapered hole in your Jet Mini tailstock. Take your old morse taper with you so you get the right one, probably a #1 or #2 morse taper. I paid $12.99 for mine at Sears & $4.99 for a Jacobs key chuck @ Harbor Freight.

Grandpa

AWood70928 wrote:

Your drill chuck needs to be mounted on a number 2 morse taper shaft and will look like the one in the picture

I can't thank you all enough. I was having a fit trying to figure out how to get the Live Center out of the tail stock spindle. Anyway, I got home from work tonight and took another look at it and used a wood dowl and hit it with a rubber mallet and it poped right out. Now I can go get a drill chuck. Thanks again.

Al

A kinder, gentler way to remove the tailstock center is to use the handwheel to retract the tailstock quill until the center drops out...............Barry

Ah Ha. And said with so much tact too :) Never once called me a gorilla :) I will give that suggestion a try. Sounds a lot easier on the equipment. Live and learn. I always keep a rag handy to wipe the egg off my face.

Thanks.

While this certainly does work for this brand lathe, it doesn't work for all lathes. Not all of them have this auto-eject feature. Just a heads-up for the new lathe owners out there.

- Andrew

Or with every taper. Some are not long enough to self-eject. Fortunately, a bit of time with some brass or aluminum and a lathe will produce an extension to make a non-ejector into an ejector.

Dummied up on the buttons. Also want to mention the wedge method, where a piece of wood is placed between the edge of the chuck and the tailstock, popping it out as the wheel is rotated to retract.

Fortunately,

Wanna borrow my egg rag? I always keep one handy................Barry

True........but it works on Jet Mini Lathes...........

Ummmmm ..... yeeeessssssss. As my statement of "While this certainly does work for this brand lathe" should have alluded to. At least I had hoped it would have.

- Andrew

al: on many NEW jet minis, backing out the live center using the hand wheel will be a bit tough for the first time ... put the live center back in and try popping it out with the hand wheel ....just keep turning and it will pop.

This doesn't work on all MT-2s. I have one Live Center that it doesn't work on - The taper has to be long enough to reach the eject device.

mike

That must be a pretty short live center taper! Good point though. How long is that taper you're talking about?

I have a couple of tapers on devices for the tailstock that are too long. Not that they don't auto-eject but that they take up an additional 1.5" of tailstock travel that they really shouldn't have to. One of them is on a Jacobs' chuck. When I get some more time, I'll hack off a bit of that taper but I don't want to go too short either.

- Andrew

Nope. Think about it. If they're designed to be able to bore through them, they'll lack the self-ejector.

That's why I mentioned two methods of extraction.

For example, the Nova is a non-ejector.

!) What does your comment have to do with the quote from my message concerning the length of a particular live center taper?

- Andrew

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.

Now, read carefully - with some centers you can bore through the CENTER , not just the tailstock, gaining extra stabilization for the piece. I even mentioned one of the type. This, unfortunately requires the center be shorter to accommodate the hollow. I have already mentioned two ways to overcome the (pun intended) shortcomings of such centers in this thread. You also use the hole in the Nova to knock out the various end appliances. There are also solid tapers, I think most I've seen are the 60 point degree metalworking kind, with no self ejection which respond similarly to the extraction methods I mentioned. The chuck which was the subject of this thread - not Andy's offended sense of importance - was probably designed to be used in one of the Taiwan drillpresses, and therefore lacks the ejection tang.

Now, ALL of this self-ejector talk is assuming something big. There have been a couple of different self-ejector mechanisms that I've seen on lathes. I'm mainly talking about the mechanism that fits into the female morse taper in the tailstock. The female morse taper, as it is extended and retracted, rides over/around the self-ejector which stays stationary deep inside. As the tailstock-fitting device (live center in this case) is moving toward the self-ejector, it hits it and causes the live center to stop ... but the female taper of the tailstock keeps going back a slight bit depending on how long the live centers' taper is. This process ejects the live center. Like I said, there are a couple of other mechanisms that I've seen (albeit on just a couple of older and fairly custom machines) so much of this talk may not be relavent to your exact lathe. Just so there's no (or at least less) misunderstanding in what we're talking about here.

Comments inline below...

Well, actually, no. Some tailstock fitting devices have this extension, which isn't part of the taper of that device, and some do not. The live center that came with my Jet Mini doesn't have any extension, for instance, and it ejects just fine. As long as the taper OR the taper/extension is long enough, then it'll self-eject in a tailstock designed for it. It's the design of the tailstock AND the length of the tailstock fitting device (just the taper or the taper + any extension on the end of it) that determines if a device is going to self-eject or not. If the tailstock isn't designed to self-eject devices, then it won't no matter how long of a devices' taper or taper/extension. So, the "self ejecting feature" is a product of the lathe itself and not the device that fits into it. But, again and for clarity (not to mention repetition), the tailstock fitting devices' taper or taper/extension MUST be long enough to hit up against that tailstock feature.

"Now, read carefully..."

Ohhhh, I do try to and ask actual questions (that I, amazingly, would like answers to) when I don't feel like I have understood what was being said. Otherwise, misunderstandings and personal attacks (see below) can ensue.

Absolutely. I'm with you here.

You lost me here. Why must the center (I assume you mean the taper of the live center) be shorter in that case? Do you mean that the taper must be shorter so that you can crank the live center closer to the tailstock and not be sticking out so far? If so, then why would that matter? In many lathes, you're only talking 1/4" of an inch difference between either ejecting the taper fitting device (in this case a live center with a boring hole) and fully seating the tailstock to full retraction.

Or perhaps (and I think this is it) you're talking about a tailstock that will allow 3/8" diameter boring, for example. If the taper of a center that allows boring through it had an extra long morse taper on it, then it might not allow a 3/8" hole to be through it. You could fit the 3/8" bit in the tailstock but it wouldn't fit into the centers' hole. So, to overcome this, the taper on the center is shortened up to allow that 3/8" hole through it. Is that right? Assuming that that is what you're talking about....

So what? That's just a design mistake of the lathe manufacturer by mismatching the boring hole of the tailstock to the size of the female morse taper of it (having a 1/2" boring hole with a morse taper #1 for instance ) AND the length of the morse taper before it hits the self ejecting feature of the tailstock when it's fully retracted if that's a feature of the lathe (to make this more relevant to this thread). If the manufacturer gets their design right, then any tailstock device with a boring hole that matches the tailstock boring hole (say 3/8" for both) will both fit the female taper of the tailstock AND the tailstock fitting device will self eject (given that the tailstock itself has that feature in the first place) AND be able to use the full boring diameter of the tailstock and the center.

You can certainly have a center with a boring hole of, say, 1/2" fitted into a (properly designed as per above) tailstock with a boring hole of 3/8" where the center will be shorter to accomodate that larger diameter through-hole. And it might not auto-eject, that's true. It's not the fault of the tailstock. It's the fault of the person using the wrong center for the lathe! If you're not going to use a properly matching center to your lathe, then you can't expect everything to work out. The auto-eject feature of the tailstock might be that failure. You're not going to be boring a

So, assuming that I deduced what you were actually talking about in the quote from your email above correctly, your answer to my question of...

"Why would the ability to bore through the tailstock negate the self-ejector feature of a piece of equipment (live center for example) inserted into it's morse taper?"

would be that of length of the centers' morse taper. And considering the statement just after the one quoted above by me....

"Or are you talking about the live center itself? I don't see where that would be relevant either as that piece of equipment doesn't have anything to do (except, obviously, it's length) with a "self-ejector" feature. Please explain yourself."

Those questions of mine were directed to you as per your statement of...

"Nope. Think about it. If they're designed to be able to bore through them, they'll lack the self-ejector."

Reading your last statement of: "used in one of the Taiwan drillpresses, and therefore lacks the ejection tang" got me to thinking (and coming back up here to insert this) that because you believe that a lathe tailstock "auto-eject" feature is the same as found on some drillpresses, the live center/Jacobs Chuck/whatever it is must be the one with the feature instead of the tailstock, right? Perhaps this is much of the misundertanding.

So, the centers' that I have that allow boring through them won't self-eject as per the above quote of yours? Hmmmm amazing! Let's take a quick and easy example of a Jet Mini with the live center that came with it. It's right in front of me and many people have one so I'll use that. I pop out the sharp point and put the center into the tailstock taper. I then slide a

Yep. It does. Need a picture to verify? Not being mean ... just don't want there to be any misunderstanding.

Should I try a few more lathes and centers? I have no doubt that I can find a couple of combinations where it won't work. But, by and large for the standard equipment lathes that I have access to, they'll work just like the Jet Mini in my test.

So, it does appear that not all centers that are "designed to be able to bore through them" will lack a self-ejector feature. Of course, as I explained above, it's not the tailstock fitting device (live center or Jacobs Chuck in this case) that has that "feature" although it must have enough length for that tailstock feature to engage it..

And those were fine recommendations.

Yes, I have a few of those as well. No problems self-ejecting here. Different models and lengths and tailstock designs are the culprits. As long as they are long enough (taper or taper/extension on it) to hit that self eject feature of the tailstock then it'll work.

"The chuck which was the subject of this thread - not Andy's offended sense of importance -"

Yet more trolling by George. *sigh* My only sense of importance comes internally from helping people and trying to give them the best information possible whether it's from me or directing them to another resource. NOT from just trolling newsgroups looking for a fight or lobbing personal attacks and cowering away from real questions. If a person can provide different opinions, evidence or experience then I am all for it. Just don't expect to not get called on it. I am not easily offended and you've not even come close. I've been through 18 years of Usenet, FIDOnet, Craig-soft, GlassRoomnet, and other online forum trolls that were far far worse than you. It still saddens me, though, that such things and people still exist. I have nothing to prove and everything of myself to offer in what limited areas of expertise that I have fought to learn. I have much to learn in many many fields of study, not the least of which is woodturning. As much as I wish the online forums to educate and inform me, I want even more for those that are just starting out to have accurate and helpful information to help them.

"was probably designed to be used in one of the Taiwan drillpresses, and therefore lacks the ejection tang."

Perhaps this is where you are erroneously extrapolating your views from? The ejection from most drillpresses is far different than from a "self-ejection" feature on a tailstock. No need for that "tang" on the end of some Jacobs Chuck morse tapers on a wood lathe tailstock. In fact, I'm going to go cut the one on one of mine off because it's not needed on the lathes I work on. It just makes the whole thing too big.

- Andrew