Dumb draw bolt question

It is a compression fit, just like all drill chucks even in drill presses. And since you are pushing against it, it should not come out,

randy

So is the taper at the other end, end yet the draw bolt is necessary there. It's possible to use it as a small chuck in the headstock without the tailstock, which is the scenario where you need a draw bolt.

If you use the chuck for drilling, the chuck could easily come out when withdrawing the from the drilled hole. The MT in a drill has normally a tang that also prevents the MT from twisting in the spindle, never seen that on a Lathe, as they have hollow spindles usually. The JT (Jacobs Taper) has quite often a treaded hole in the shaft to hold the chuck on, especially on handheld power drills or sometimes the chuck is threaded and then the screw is left-hand threaded to keep the chuck from unscrewing when the gun is turning reversed. If I had to mount the chuck on the taper I would first clean the JT and the chucks JT also then place the taper into the freezer for an hour or so then use a mallet to seat it good, it should stay on if done that way. Can you use the chuck without the draw-bold in place, sure, but if the MT shaft spins around and scores the spindle surface you'll have a real problem on your hand, I never use it without the bolt installed, but that's up to you. O, I have a good quality made in the USA "Jacobs" chuck that I got for free because it was just pressed on and did come loose, scoring the chucks JT, I was able to renew the surface and have used it for years now, (was a $80.-- chuck at that time :-)))

Have fun and take care Leo Van Der Loo

Right, I've replaced a couple drill chucks and it's always been threaded and with a screw retaining it, which is what is throwing me here. It just seems to me that the logic in using the draw bolt assumes that the MT is permanently attached to the drill chuck, or that the draw bolt goes through a through bore and is secured inside the chuck. But I see the same exact chuck and spindle for sale everywhere I have looked. There is a little dimple at the end of the JT that would make it easy to drill and tap, but there's nothing in the chuck to attach to.

Worth a shot, but won't it just push itself out of the taper when it warms up?

Not fouling up the lathe taper is a good enough reason for me, I just don't want the thing flying off if I use it as a chuck. I guess I need to suck it up and get a scroll chuck.

One other dumb question. My lathe (Turncrafter) doesn't have a spindle lock. There are a couple of 1/4" holes 180 degrees apart. The faceplate has flats for a 1-1/4" wrench. Are the holes supposed to be for a pin wrench, and am I supposed to tighten with wrenches when installing, or is hand tight sufficient, and the holes and flats are just for getting the thing off if it got jammed in place? The manual is completely devoid of anything resembling information, and the book I got doesn't say anything about actually installing anything.

Ass-u-me-ing that we're talking about using the chuck in the tailstock?

I've never gone the draw bolt route.. scares me worse than other scenarios that I can come up with..

If the chuck spins in the taper on either the chuck or lathe end, it means that something is binding, right?

If so, I'd rather stop the lathe when the chuck spins a bit (usually less than

1/2 a revolution) and see what's binding than have it grab in the hole and burn/break/shatter whatever I'm drilling...

The only drawbolt I use is for the Bealle buffing wheels, but that's because the wheel, unlike the drill bit, isn't being pushed into the taper, and the speed is in the 1,800 to 2000 rpm range..

mac

Please remove splinters before emailing

There are self holding tapers and self releasing tapers. The #2MT taper that goes into your headstock spindle (I assume) is just about a self holding taper and the JT certainly is self holding. That's why the JT series taper shanks and sockets don't need a drawing-up mechanism to hold the parts together. I am mostly a metal machinist. Right now I am doing a job where I have to drill 7/8" diameter holes 3 1/2" deep in annealed tool steel (in the lathe). I do this by holding the 7/8" drill bit (which has a 1/2" shank) in a drill chuck that is held into the tailstock with a #2MT taper. I don't have a draw bolt and they never come loose. The main reasons for having a draw bolt for your headstock chuck are two:

1. The shank may come loose if you apply side loads to the chuck, which you might do if you had a 5" sanding disk's shank held in the chuck.
2. If the female taper in the spindle is already slightly damaged or if it is dirty at all, the shank will probably come loose.

I check the female tapers in both headstock and tailstock from time to time by coating a known good shank with felt tip marker, letting it dry, then inserting it gently into the hole. I gently twist the shank, then remove it and look for the amount of contact I am getting between the two parts. If I get several lines where the felt tip marker rubbed off, or even some areas where the "line" has some width to it (say 1/8" or so), then things are in good shape. If there are only one or two places where the parts contact, then the taper must be cleaned or reamed before use.

Pete Stanaitis

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There are/were many different tapers around, and they all have in common that they hold well without releasing themselves if pressure is applied, the JT will not slip out if shrunk tight in place. I also have a little Delta midi lathe, and it came with a bar that can be used to knock-out the spur-drive and center, I also use that for holding the shaft to unscrew the scroll-chuck or faceplate. The way to install a faceplate or chuck, is to screw it on all the way, than back-off a 1/4 turn and spin it back on with a flick of the wrist, that's all thats needed and will also ensure you also can get it off easily again. As to what Mac is saying, the lathe at a slow 600 RPMs has turned 10 times around in one second, if one can realize what's happening and shut down the lathe in 1 second, they are real fast, but 10 revolutions can do a lot of damage, if the chuck is seated well it should stall a small lathe rather than slip and spin, with high powered machinery there can be problems, though that's wy they use large MT, my large lathe has a MT5, and they do come in larger sizes than that.

Have fun and take care Leo Van Der Loo

I have both wood and metal lathes.....

The Morse taper that is threaded is for dual purpose needs.

1. When drilling with the tail stock - the chuck on the MT mandrel is cleaned, the tail stock taper is cleaned. (they make plastic reamers ..)

In any case, the mandrel is pressed into the tail stock and the outside of the chuck is gripped with a hand as drilling.

If you have rust or bumps on the taper (inside or out) a Atomic fit won't happen and the taper turns. Atomic fit is that when the two tapers mesh so close the ionic bonding holds it tight.

On the head stock end - that is where the draw bolt is needed.

The draw bolt can be as simple as a threaded rod through the spindle into the taper. The outside end is the trick. You want that centered and held tightly. A cone shaped nut is normally used to self center the outboard end on the tail stock.

I've made some from Delrin (trade name for Actel) the white or black machinable plastic (better than nylon) as it compresses a little. It is used to keep the taper in line 2 feet (maybe) away from the MT.

The screw type gives options. The older tang (lower cost...) was for use with flat wedges used perpendicular to the center of work.

Martin

Martin H. Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal. NRA Second Amendment Task Force Charter Founder IHMSA and NRA Metallic Silhouette maker & member.

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Yup. You need a drawbolt if you don't use the tailstock.

1. jacobs taper is a self holding taper that will take SIGNIFICANT force before letting go, the morese taper holds much more weakly. If you seat your chuck properly on the JT, it won't separate in normal use

1. no need to tighten with wrenches, snug up and go - do not let hte chuck spin on fast and slam into the shoulder, you'll have a pretty time getting it off

2. I've never seen a JT mounted drill chuck that also had a screw to hold it to the taper, but I've only looked at a few hundred - I have seen lots of threaded chucks with the subject screw hole.

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Morning Leo..

I usually bore at between 200 and 300 rpm, and have never had a Morse taper( #2) come even close to free spinning while drilling.. What I was referring to is a slight slippage, like a slow motion stuttering, which tells me that either I'm forcing the drilling, have a dirty tailstock taper, or both.. My Jet 1442 wouldn't stall, so I'd have a problem at speed if the drill bit bound up.. The Nova is pretty good at stopping the spindle by itself, 'if' I remember to set the computer to "soft".. OTOH, the Nova will try to put more power to the spindle when it slows from pressure, which can be good or very bad..

IMO, if someone is using high speed or too much pressure, it's time to take a break and relax for a while.. ;-]

mac

Please remove splinters before emailing

Here's my story, which I've told here before. After drilling a 2" hole with a spade bit (using a draw bolt) I was nonchalantly backing out while the lathe was still running. Not paying attention, I backed the Jacobs taper out of the chuck. When the chuck started flailing around hitting the ways every round it woke me up very quickly. I was afraid to move in front of it to turn the lathe off so I RAN to the switch box and threw the breaker.

There was no serious damage done, and a terrifying lesson learned. So, no, using a draw bolt is not a total prevention of a mishap.

So in summary, that's quite a few reassurances that everything will be fine, and one who had to change underwear when it wasn't.

Just to throw this on the fire, this is what the Lee Valley website says that really started this:

"One of the handiest lathe accessories you can have, this drill chuck can be used for both turning and drilling applications. To use in the headstock as a turning chuck, you first turn a spigot on the piece and then put the spigot in the chuck. For drilling, it can be used in either the headstock or the tailstock."

So they specifically say you can use this in the headstock for turning but obviously they aren't implying you can turn bowls with it or anything like that.

Specifically, I need to make some short 1.5" diameter dowels that are rounded on one end. My intention was to do as much as I can between centers and then clean up the tip holding it in the drill chuck. It's already going to be round and I'm only cutting basically in line with the drive so this is probably ok? Or should I make a jam chuck? I need three 1.5" and three 1-3/8" diameter.

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unless you are buying a VERY expensive and large drill chuck, it won't hold anything with a 1 inch diameter - I have a jacob's chuck that will hold 3/4 inch, a new one of those is several hundred dollars - 1/2 inch max is much more common. I think to do what you want you need to come up with a different method. a scroll chuck, a collet, or a jam chuck will all work.

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As Bill said, this isn't an application for a drill chuck, unless you buy a HUGE one.. Mine are both 3/4" capacity, a lot of them are 5/8" or 1/2"..

I guess you could put the dowels between centers, turn a tenon on the end and then put them in the drill chuck.. IMHO, that isn't worth the cost of buying a drill chuck, unless you think you'll need it later..

In my case, for less than 1.7" diameter, I have to change the jaws on my scroll chuck to the spigot/pin jaws..

I think you'll find that either a jam chuck, like a 3/4" hole in a faceplace block or whatever, is the easiest way to do a LOT of dowels..

Unless I was doing over maybe 25 or so, I'd just get them as close as possible between centers and then clean them up by hand wait a little sandpaper.. If you're way out on the end, a belt or palm sander will work.. YMWV

mac

Please remove splinters before emailing

I was thinking if I make 3-4 of them in a row (my blanks are plenty long enough) then as I am removing the material to get to the nose of one then I get the tenon for free on the next one, but doing them nose to nose would make more sense if you didn't need the tenons.

I'm making some big toy train locomotives modeled after a 2-6-0 Mogul, mostly because I have an HO model of one so I could take measurements. I didn't much care for all the stuff I saw looking around online made from a 2" dowel and factory wheels and smokestacks.

I figured it was a good first project, though I'm starting to think it's like the scroll saw - easier to make a curve than a straight line. I got the drill chuck to do the wheels, though I think for the larger drive wheels I'm going to try to rough cut them on the band saw and then use a jig at the router table to clean them up.

But, Doh! Even though the tailstock is a MT#2, the MT on the spindle won't go all the way in. In the tailstock immediately at the end of the taper the inside diameter gets much smaller, and the spindle has a straight section after the taper, the diameter goes down a bit but but not enough to clear.

I did end up trying to turn a 1/2" tenon and use it in the jacobs chuck, didn't work that well. Made a jam chuck. Didn't *quite* manage to pop it in there with the lathe spinning like Richard Raffan, but I eventually found where it landed ;) It wasn't hard even for someone with no idea what they are doing and it worked great.

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