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http://www.americanmachinetools.com/Line_Boring.htm

They're using the mag drill the way I did it. I was lucky my biggest holes
were two inch. My bucket was similar to the one in the picture. I set up the
drill four times - each side of each support. I see this line bore would do
it in one shot.

For mounting the mag drill you got to think outside the box sometimes. The
vertical pins that swings the whole backhoe were totally shot. There's
nothing left to mount to after removing the hoe. So, I mounted the drill to
the loader bucket of another tractor, got a pile of blocks and pressed the
bucket down on it. This worked really neat cause adjusting the angle was
just bucket tilt.


You're probably aware that you only have to bore that line very rough.
Portable align-honing equipment to finish the job will take out a lot of
metal these days, although you won't be able to take out the tens of
thousandths they get with fixed diamond honing machines.


My efforts were REALLY rough. A carbide burr on a die grinder will move a
hole over quickly.

Good luck in your project.

Karl