Boring out the center hole on a Buck 6 jaw chuck

[gt40]

I know it may be sacrilege to do this but I thought I would share. I recently got a 4" used Buck 6 jaw chuck. The center hole was 1.06" when I measured it. After taking it apart and cleaning it and examining the way everything went together, clearance between the bolts etc.I bored it out to 1.25". I must confess I felt a little bad modding a beautiful precision chuck like this but I still have plenty of steel supporting everything. Now I can fit a mag c body in it. I ran a copper 1" rod in it and took some cuts and everything works the same. I still need to bore through the adaptor plate I made but all in all it seems to work. Here are a couple of pics:

 

[gadget_lover]

Some things are just considered to be "improper". First we have nude tools and now you have deflowered a pretty little buck-chuck.

What's this site coming to?

Seriously, how well did it maintain it's concentricity? Can you turn a rod, remount it several times and get the same run-out as before?

Daniel

 

[precisionworks]

As long as there is still adequate support for the scroll plate, you should be fine - especially on a smaller chuck.

The draw back to your mod is that the jaws have less support when gripping very small diameter parts - you opened the bore up by .190" on the diameter, so there would be as much as .095" of each jaw that has no support when gripping a minimum diameter part. As long as your part is .190" diameter or larger, you won't notice a difference.

 

[cmacclel]

That must have sounded like an apache helicopter in your living room while boring

Mac

 

[will]

I bored out the chuck on my mini lathe so I could get the body of a mini mag all the way through. I went all the way through mine.