Boring bar holder ineffective

[Dan Krager]

I have an AXA boring bar holder that uses two bushings to hold a 1/2" boring bar. But the bar almost spins like a top... the grip is not strong at all. I have disassembled to check for defects or issues. Perhaps the issue is the user. Any suggestions?

DanK

 

[pontiac428]

A 1/2" boring bar should fit fine in a standard set screw type tool holder. Looks like doubling up on sleeves is giving you growing stacked tolerances, that's my guess. Probably will introduce play in other axes as well.

 

[rabler]

Can you turn a single bushing and slit it with a slitting saw?

 

[Liljoebrshooter]

Are the clamping bolts in it? Can't see them in the picture.
Joe

 

[Batmanacw]

Line up the slits on both sleeves on the side with the bolts so they pinch both sides of the slit.

 

[Dan Krager]

Now why didn't I think of putting it directly into the tool holder? Duh. I can turn a single bushing and slit it. Wasn't sure that would work any better. Yes the bolts are present and they have tapered flats to draw against the bushings. And I did position the bushings so the bolts bore directly on the slit, at 90° to the slit and at 180° to the slit. No changes noted. And I stopped short of putting a cheater on the wrench for tightening and I put all I could muster into the tightening. I do have another boring bar holder with bolts that squeeze two sides of a slit together for holding. I guess a double bushing is just not an effective way to hold something. Thanks for the input.
DanK

 

[benmychree]

A bushing in a bushing is not a good plan, make a new separate bushing for the smaller bar, the tool holder that has a vee groove in it is fine for small bars, no need for the tool holder shown for small bars.

 

[OTmachine]

Can you turn a single bushing and slit it with a slitting saw?

Or hack saw

 

[ddickey]

Are you sure it is a 1/2" and not a 12mm boring bar?

 

[RaisedByWolves]

Now why didn't I think of putting it directly into the tool holder? Duh. I can turn a single bushing and slit it. Wasn't sure that would work any better. Yes the bolts are present and they have tapered flats to draw against the bushings. And I did position the bushings so the bolts bore directly on the slit, at 90° to the slit and at 180° to the slit. No changes noted. And I stopped short of putting a cheater on the wrench for tightening and I put all I could muster into the tightening. I do have another boring bar holder with bolts that squeeze two sides of a slit together for holding. I guess a double bushing is just not an effective way to hold something. Thanks for the input.
DanK

Imo it’s a junk design meant to make you think you’re getting more than you bargained for.

The only issue I have with putting your boring bar right in the tool holder is it can mark up your shank if the set screws have anything other than a square flat dog point.