Different MT2s ? (and Jet/Delta lathes)

[Joe Judge]

I got another, small Jet-like lathe (Delta LA200) and noticed that my jacobs chuck ... won't' fit !?!

I guess it would fit, if it would insert all the way. You see, the arbor has a little tang sticking out the end, and the headstock seems to have a reduction inside of it.

So, my arbor is too long? my arbor is some other type (J3 J<something? what do those mean?).

I guess I need a new arbor or new chuck+arbor, where the arbor is short(?)

-- joe

[Jim Becker]

Some lathes will not accommodate a Morse Taper with the tang. Do note that you should not use a chuck that is mounted with a MT in the headstock unless you also use a draw bolt to secure it to the machine. The Jacobs is normally used in the tailstock for drilling into blanks mounted on a chuck or faceplate. It's certainly useful for mounting very small things on the headstock, but again, a draw bolt is required for safety.

For those not familiar with the term, a draw bolt is typically a piece of threaded rod that goes all the way through the spindle, screws into the end of the MT and is secured at the outboard side of the headstock spindle with a wing nut or other type of nut.

[Ken Fitzgerald]

Joe....Jim gives pretty sage advice! I use a Jacobs chuck for turning bottlestoppers. I tried ONCE to turn one without a draw bolt. I got tired of chase the bottle stopper blank. No matter how sharp my skew was, when I applied it to the wood, the chuck came out of the head stock. Any time I use my Jacobs chuck in the headstock, I use a draw bolt. My jacobs chuck has a 1/4x 20 threaded hole in it IIRC.

[Allen Neighbors]

There are Jacobs tapers and Morse tapers... and never the twain shall meet. :) But. Jim's right, all the way.

[Joe Judge]

I've only used this jacobs chuck in my tailstock.

So, maybe I solve my problem a different way -- time to buy some spigot jaws for the oneway chuck :-)


--joe

[Curt Fuller]

I have (had) a Jacobs chuck with the flat tang at the end of the morse taper that I think you're refering to. I ground it off and now it works fine in both of my lathes. I'm not sure what the purpose of it was but it wasn't anything I've missed so far.

[Jerry Allen]

I think the tang is used in metal working lathes as a positive drive.
I have used my Jacobs chuck in the headstock a few times, usually using the tailstock with a cone center to support the work. Without pressure towards the head, the MT2 is likely to slip or come loose.
There are lots of different MT2 items available. Most of them were not made for wood lathes and are generally ~.4" or more too long. That either causes them not to seat as intended, or the ejection mechanism in the tail not to work. When I get an MT2 item that is too long, I cut it off with and angle grinder with a cutoff disk or hacksaw, and clean it up with a file and belt sander, etc.. I use the stock center that came with my lathe as a guide. The dimension is about 2.3" long, but it is best to measure your current stock parts to get the correct dimension. The dimension can be shorter than it would appear due to extra shoulder length on some chucks and live centers, so mark a stock center at the point it exits the spindle and measure from the mark to the end rather than the back of the head/chuck to the end.

[Dave Noon]

The Morse tapers with a tang are typically used in drill presses. A drift (wedge-shaped bar) is used to remove the chuck by inserting it through a slot in the quill and driving it with a hammer of mallet. The tapered surface contacts the tang and drives it out.
On a wood lathe the spindle has a through hole in order to use a push rod.
Hope that helps.
Dave

[Marvin Hasenak]

Screw the quill out about 1" and then try it. The MT seat in the LA200 is for a short 2MT arbor.

Marvin