At post #10 on this thread
http://www.tractorbynet.com/forums/attachments/104710-post-hole-digger-slow.html bindian shows pix of her auger on her backhoe. Is this the thread you meant?
That's not the thread that I was thinking of, but the second pictures show it very clearly. In the thread I'm thinking of, she was talking about it, and I asked her to show a picture. It might have been the same picture, I don't remember for sure. I am going to copy that picture you linked to and keep it my "ideas" folder. I have all sorts of pictures that others have done that I want to do some day, and that's one that I need in there.
If I come across a great deal on a hydralic post hole digger, that's just what I'm going to do. I have a 3 pt unit now, and while it gets the job done, it's lacking in allot of ways. Mostly just lining it up where I want it, and then keeping it going straight down are the two biggest issues. Then I'm limited in how deep I can go because of how high I can get my 3pt lift. 3 ft is about my maximum depth, and while that's proven to be enough, I still want that option of going deeper.
I think that with Brandi's method, you will have the ultimate setup that will allow you to get the auger exactly where you want it, and also to keep it perfectly straight. Being hydraulic, you can also back it out of a hole, as opposed to a 3pt, where you have to get a pipe wrench to unscrew the auger if it gets in too deep, too fast.
Of course, with the setup that you bought, it's either as simple as fitting it on the pin, or making an adapter, and then running some hoses. If the bucket curl is removed and the hose gets a quick attack to the cylinder, you should be able to remove those hoses from the cylinder and control the auger with those hoses. Maybe even put a valve on the hose to divert the hydrualic oil from the cylinder to the hoses running to the auger. At least that's my idea. I don't know if it's doable or not. LOL
Eddie