Sounds like an interesting project.... How long do you intend to reach out beyond, say, the original front cutting edge of the bucket ? We have one of those forklift booms we put on the skidder at the shop, and that thing really gets heavy all by itself even when its collapsed. When I think of perhaps how my 644 would handle such a thing, I'm thinking I wouldnt want to be much more than a foot past the original cutting edge line or I wouldnt be able to lift all that much. Having a short pole there over a bucket though sure would give a guy a lot of room to see and pinpoint locate the load though.
Maybe you can get some ideas from this little luffing boom being put together down the road from me:
http://www.data-cut.com/images/31000-1.jpg - 5 blocks away.
http://www.data-cut.com/images/31000-2.jpg - 3-4 miles away.
Those are photos of the new 31000 series cranes being built here at Manitowoc Crane. The main lower boom in the photo is about half length of maximum, and I am told that the luffer can go another section or two. Not sure if they will have room in the yard to set it up at full length as they have a LOT of cranes underway right now.
The main booms 4 base legs are 12.75" Diameter and 1.75" wall thickness. The operators cab is larger than my kitchen.... A decent comparison as I have been told it does contain a microwave and refridgerator.
The "sister" crane to this one is already built and can be seen just in front and to the right of the erected one in that first photo. As of today, they have the sister erected with a much longer main boom and a short luffer, and it shockingly stands every bit as tall as the one in the first photo. If it stops raining up this way, I want to get some more distant photos. I was out about 10 miles the other day without my camera.... the thing looks taller the farther you get away from it !
You can find some closeups of boom segments in this forum... you know, for some ideas on your jib ! LOL !
http://www.bouwmachineforum.nl/forum/vi ... hp?t=13902