T posts... prefer a backhoe. and a pipe i can catch to top of T post in. the backhoe lets me move back and forth in various direction. to deal with the "bent post" happening, along with keep from bending the post. also lets me just "stab" the T post in by hand. even if T post almost falls over to the ground. i can grab T post with backhoe bucket / pipe end and get it straight.
i have wanted to try a ground rod driver on a T post but never had one around to try when needed a T post put in.
backhoe and ground rod = *meh* it work, but ended up with bending a ground rod and had to pull it out and get a new one put in. ground rod way to long and flex / bent.
i have tried a hammer drill for say using a concrete bit to drill a hole. *meh* did not work.
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google
post driver site:tractorbynet.com
then click up on images. there are a few threads of different DIY builds of post drivers that i do remember seeing over the years.
the site:tractorbynet.com only brings stuff back from this website. vs searching all websites.
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contact a local rental machinery place. there is a couple places about an hour in each direction, that rents out nearly everything that one could need, from simple hand tools, to trailers and tractors. if memory serves they also have a post driver to rent out. beyond the normal augers ( 1 man, 2 man, 3pt hitch, skid steer)
have seen, shot gun shell like post drivers, to LP units, to air compressor units, to hydrualic units, then extremely expensive units that connect to a backhoe. and pick up off of a trailer level it and sink it into the ground.
not sure if i could deal with the shot gun shells, or LP versions, seem rather expensive waste.
the air compressor units seemed to be nice. just looking at them over internet. looks to be like a standard 2 handle man handled T post driver, but instead of muscle an air cylinder to lift it up, and some valves and a trigger. i would imagine they still weight a descent amount. but still life saver on the muscles and shoulders, upper back, neck.
one of the DIY post drivers here on TBN. had a sledge hammer on a track setup. that raised the weight up and let it come down on post to hammer it in, yes, it looked "old school" but simple enough in design. i want to say the builder was putting in 3" or 4" wood posts with it. maybe same person or another DIY builder doing 6" posts. and i want to say they were not "making the bottom end of post into a point" but straight cut on end, and just hammering them in. i do remember comments of some went in at an angle. (connected to FEL, single person doing) nothing they could do about it, beyond try there best as they could.