Lathe and Drill Chuck Problems

[Mark Waltrip]

Lathe: Jet JWL-1236
Headstock & Tailstock Taper: MT-2
Drill Chuck Taper: 2JT
Drill Chuck: Jacobs 14442 w/ 2JT taper

OK, so I bought a drill chuck to go with my wood lathe, an adapter that is supposed to adapt a 2MT to 2JT, and for some reason the 2MT end doesn't work with my lathe.

The 2JT end fits perfectly into the Jacobs Drill Chuck, but the other end of the adapter, 2MT, doesn't fit into my tailstock or headstock. Well, it fits, but it doesn't lock in like it should.

Any suggestions on where I'm going wrong?

[Dick Sowa]

Tapers don't "lock" into place, as such. They are held in place due to pressure along their axis. For example, if you have a blank mounted on a faceplate, and mount the drill chuck/MT in the tail stock, as you advance the quill, and drill into the blank, it wants to put pressure on the MT and snug it up tighter in the tailstock.

One way to tighten a MT in a hollow spindle is to use a draw bar. The back end of the MT is threaded so you can insert a threaded rod through the spindle, into the back of the MT, and pull the MT tighter into the spindle.

An alternative is to use just not use a jacobs chuck at all, and use collet chucks. Those also include draw bar threads for tightening. Here's a link for some. http://littlemachineshop.com/products/product_view.php?ProductID=1752&category=874479994

[Steve Campbell]

Mark just get a draw bolt for your chuck and have at it. I had the same problem when I started out. The draw bolt I made was just a length of 1/4 inch ready bolt from the hardware store and a 1/4 inch wing nut. You don't have to tighten it up very much. It just keeps the chuck from starting to move. I hope this helps.

Steve

[Bernie Weishapl]

They don't lock into you tailstock or headstock. I watched several demo's by pro turners and all said you need to hold your jacobs chuck as you drill to help keep it from turning in your MT. If it turns you can score the MT. Even if you use a draw bolt and it turns on you it may cause problems.

[Cyril Griesbach]

Mark, when I drill on the lathe I put the drill chuck with #2MT in the tailstock. My lathe, and yours probably as well, has a self ejecting quill. That is when the quill is completely withdrawn it will kick out the live center or what ever it is you are using. My guess is that your 2MT for the drill chuck has a tang on the end which the live center does not have. You may have to extend the tailstock quill a bit extra to accomadate this tang and it should work fine....if that's what you're doing.

[Dean Thomas]

Hey Fellow 1236 owner,

Pay no attention to most of them thar folks that don't own this lathe. It just has its own way of looking at and working with the world. Cyril's right, though, about the tang, but extending more won't help! If it's in the way, it's just in the way. I've got one of those, too. :)

Tapers certainly ARE supposed to lock into place. What the heck do we need knock out bars if they don't lock in place. C'mon guys!

All MT2 holes are not created equal, and neither are the tools that fit them. Yes, the ratio and the angle of that taper are all pretty darned close, but some are longer/deeper than others. I have an MT2 based chuck for a different brand. There is a little shoulder at the top of the taper (darn!) that keeps the chuck from anchoring. I have several dead centers that I have used as poor imitations of Oneway's Safe Drive. Some of them are too long and will not go all the way back into the socket.

Not all MT devices are threaded. Some do just have tangs. Some have shoulders. Some are blunt and solid/square. I have threaded ones that still won't work because the item is too long for the socket.

Yes, careful about spinning things in the socket. Scarring can happen and you DON'T want it!!

These are just the facts of MT life. Find your Jet live center and check the MT2 taper against that center's taper. Check for length, check for shoulders and see if you can find the way to get the chuck to work. I just have to hang onto my chuck, but it works, even with a 3" Forstner bit. It will NOT get tighter as pressure is applied. Can't. Durned shoulder...