Confucious him say "Brace with bowed axis go wobble"

[ivan]

Now retired, there's more time to hand tool, so I dug out a Stanley brace bought in 196* and hardly used since. First job was to fit a mortice lock to a solid oak front door. Whilst brace and bitting out the waste I could not help noticing the chuck was wobbling in a circular fashion. I rolled the jennings bit to see if it was straight (yes, and rust free and virtually new), cleaned the alligator jaws and added new grease, and tightened firmly - no change. As far as I can see, the drilling axis, chest to point, is bowed. Since then, ebay has delivered 6, 8. and 12" variants, all Stanley, wooden head, attached with 3 screws, and alligator jaws; and they all wobble as the axis is bowed! It's not easy to see if the bows needs bending, or if the chuck is the problem (rotating the bit in the chuck has no effect). I doubt any of these would happily drive a screw (one more reason to dig out the brace). Any thoughts on tuning up a brace to working spec?

 

[xy mosian]

Strange. I have one with a similar problem. I intend removing the chuck and checking alignment of the 'on axis' shafts at each end of the bow. I suspect the bow as the plastic winding handle sticks at the same point of its rotation every turn.
Fortunately mine seems to be not as bad as yours and is not an urgent problem. I'll get around to it when the weather warms up a bit.
I would like to remove the winding handle but I'm not sure I can do it without ruining it.
xy

 

[AndyT]

I've noticed the same thing sometimes, but decided it's one of those things that's a problem in theory, not in practice.
If you are boring a shallow hole, it won't matter. If you are boring a deep hole, the body of the bit keeps it straight. And in either case, the "error" is distributed evenly all round the circle, in a system where the other end of the brace is fairly free to move around, even if pressed against your head, hand or belly.

Have you tried making a hole in some scrap to see if it ends up straight?

 

[Corneel]

Indeed, every brace wobbles. I have bend some braces that were particularly bad, but they still wobble a bit.