Arbor Question

[jbg230]

Pardon the naivete. I'd like to start drilling on the lathe and am looking into drill chucks. I have a MT #1.
What's the difference between a 3JT and a 6JT arbor? Does the JT describe the chuck or the arbor?
Thanks. Jake

 

[magpens]

The JT tells you that the arbor requires a Jacobs chuck with a particular taper.

You will notice that the arbor has two tapers on it.

On one end there is a taper which fits into your lathe tail stock, which will be a MT1 taper, it seems, in your case.

On the other end of the arbor is a shorter taper which fits into the back of a Jacobs chuck. . This taper will be designated as a JT3 or JT6, for example.

You will have to provide a Jacobs chuck with an internal taper that matches the external taper on the arbor. . The taper of your Jacobs chuck will be stamped or engraved on the side of the chuck.

 

[eharri446]

I would try to find a chuck and arbor which screws together. I have had several of the double taper ones come apart at the taper.

Also, as you have probably seen on the posts make sure that you hold the chuck in you left hand and advance and retract the tail stock spindle with your right. That way things do not come flying apart on you.

 

[Loucurr]

Get a 1/2 x 20 MT1 and then you can purchase a Jacobs chuck from HF threaded for 1/2 x 20.

 

[jbg230]

Thanks guys. I was at work and went too fast reading through this. Now it makes sense. I thought I'd save a few bucks by getting a Jacobs chuck with two tapered arbors (I saw a good deal online). I like the advice given here though and via Ebay and HF, I'll get the 1/2" chuck that threads over the MT#1 arbor. Thanks for clearing this up.