6" chuck for an A2-6 spindle

[SeymourDumore]

Guys

Are there any Kitagawa - compatible 6" chucks out there that would direct mount to an A2-6 spindle, or I need to go with an adapter plate from A2-6 to A2-5?

Thank You

 

[wmpy]

Yes, these are made. I did a quick search, and Strong, Pratt-Burnerd, Bison all seem to make them. There are probably others.

Try QCS Workholding. They're my go-to when looking for odd chucks. They rep all those brands I mentioned.

 

[SeymourDumore]

Thank You!


Loks like PB makes them in a wide variety from A2-4 through A2-6 and in multiple master jaw configurations.
That said, I don't know what they mean by direct and indirect mounting? Perhaps the adapter plate?

 

[wmpy]

My guess is that with the direct mounting, the A2-6 to plain back adapter is bolted directly to the back of the chuck. You don't need to remove it. When mounting the chuck, you just use long bolts that go through the chuck body and adapter plate into the spindle.

With indirect mounting, you can't do that. You have to mount the adapter plate to the spindle. Then attach the chuck to the adapter plate. It adds another step to the mounting of the chuck so can be a little bit of a pain if you're changing chucks a lot.

I think indirect mounting is necessary anytime you're putting a non-standard chuck size onto a spindle. (6" chuck on A2-6 or 8" chuck on A2-5 spindle for example) The bolt holes through the chuck don't align with the mounting holes in the spindle face.

 

[SeymourDumore]

Actually, now that I am re-thinking this, the adapter plate is what I need.
The machine will have an A2-6 nose as it normally comes with an 8" chuck.
I don't want the 8", but do want a 6" instead, but those are typically A2-5
So, I'll put on an A2-6 to A2-5 adapter, and can use a standard B-206 Kitagawa 6" chuck, along with the 2 different 5C closers I already have, both A2-5 mount.
If I need to switch to the 8" chuck ( likely never ), I just take off the adapter plate and off I go...


In any case, I asked way too soon before thought the thing through.....

Thanks anyway!!

 

[wmpy]

The only downside to that is that you'll be sticking out from the spindle more than you could be. My guess is that it wouldn't affect much, though.

 

[SeymourDumore]

Not overly concerned about that.

I have one machine where I've adapted from an A2-6 to an A2-8, and it's only about .750 longer ...
Besides, going with a smaller chuck means I am machining smaller dias as well, so rigidity requirement is less.

 

[Pete Deal]

Why would you want to add an adapter plate to the mix? Seems like swapping out a 6" chuck with an A2-6 mount to an 8" chuck with an a2-6 mount is pretty easy. I swap a2-6 chucks around all the time bolted right to the spindle.

Unless you're concerned about it being difficult to find a 6" w/A2-6 mount. Seems like it would be pretty easy though.

 

[SeymourDumore]

Pete

The only brand I've found having a 6" chuck with an A2-6 mount is Pratt Burnered, and even then the brochure says: "indirect" mount.

I think bit of the confusion comes from the spindle type definition.
Typically the 6" chucks are A2-5, 8" chucks are A2-6, 10" chucks are A2-8 mounts.