Boring on the "back side"

[kspringer80]

I think I have this thought through on my own, but always welcome others to fill in any assumptions I've made before they bite me in the hand. I just got a set of boring bars that I'm quite happy with. I can hold the 5/16" and 3/8" bars in one of my QCTP holders, but not the 1/2" bar. I have a home made boring bar holder that doesn't work with the factory milled flats on the 1/2" boring bar, however it will work if I mount the boring bar "backwards" with the cutting edge facing away from me as I operate the lathe. I'm assuming I should be OK with this as long as the saddle lock is engaged and the cutting tip is just a tad lower than centerline. I'm not planning on taking heavy cuts with this set-up, just some light cuts that I need to reach deeper than the 3/8" bar allows. Material will be 7075-T6 & 12L14... Please point out anything I'm missing, I'd prefer to avoid another crimson streak across my safety glasses!

 

[xpylonracer]

If I understand you correctly you have rotated the tool through 180 degrees so now the cutting edge is facing down to the bed shears and you are cutting in the back side of the bore. You have already taken the precaution of checking gibs are close fits to minimise any unwanted movement due to upward force on the tool tip. Using this method does enable the swarf to fall away if in a fair sized bore and also you can actually see the cut proceeding.

 

[Tin Falcon]

1) not an original Idea ( sorry to burst bubble)
2) acceptable practice.
3) remember no more than 3 x D stick out on a steel boring bar.
4) works for threading as well.
5) some cnc machines have a back tool post or one front one back.
Tin

 

[kspringer80]

Thanks Guys, I certainly know its not an original idea... I've read about it being done, but wanted to make sure I wasn't overlooking anything on setup before trying it myself.