Powered T post driver

[BHD]

been thinking about the hard ground and rock question, I have the small unit and I think it hits about as hard as my hand driver, (big difference is I do not have to lift and slam it down), Ok with that said,
My guess is that if it can be driven with an equivalent hand driver, the machine will do it, (I can drive a post in frozen ground it may take me 50 or more wacks with the hand driver to do it, and my guess is the harder it is the less progress one will make with the air driver, my unit weighs about 27 pounds or so, yes there is a down force by air, but one can only drive it down so fast and hard, just like a hand unit,
so I will say this if it can be driven in by hand then most likely this will do it as well, MY GUESS Is that the heaver larger units will drive more than the small unit,

so if your not able to drive a tee post in the soil or ground by hand most likely this will not drive it in either, in rocky soils if you hit a rock and the rock does not break I doubt if your getting through it or past it,

and unless the guy driving a well hit rock, one could fill the pipe with water and let the well point wet the ground down at the point, and come back the next day and try again. just like I many times do with hand digging a post hole, dig down about 6" fill with water comeback the next day and dig as far as is workable and if needed fill again and do it the next day, and finish out the hole,

 

[BHD]

Reporting back,
I put in a mile of fence T posts, the last few days, and the pounder worked well for driving hem but the controls were very finicky, part of it was the soil conditions, some what soft on the surface, and solid, and there is a weight on the on and off lever, and on softer soils the heaver weight is better and on solid the lighter weight is better, problem was on the soft it would end up between the cycles if you had the light weight on, and the opposite on the solid other way so I ended up keeping it set for the harder ground,

It was hard enough that in some places it was only driving a bout 1/32 of an inch per hit, very hard soils,

as far as the driving it was great, get it started and then go lean on the truck or get some thing else ready to go and let the driver work.

I really do not think one could have pushed them down with a tractor loader bucket,

 

[newbury]

Thanks for the update!
This is now in my plans.
I've a makita 2400, 4.5 cfm@90psi, do you think this will run it well?

 

[two_bit_score]

Reporting back,
I put in a mile of fence T posts, the last few days, and the pounder worked well for driving hem but the controls were very finicky, part of it was the soil conditions, some what soft on the surface, and solid, and there is a weight on the on and off lever, and on softer soils the heaver weight is better and on solid the lighter weight is better, problem was on the soft it would end up between the cycles if you had the light weight on, and the opposite on the solid other way so I ended up keeping it set for the harder ground,

It was hard enough that in some places it was only driving a bout 1/32 of an inch per hit, very hard soils,

as far as the driving it was great, get it started and then go lean on the truck or get some thing else ready to go and let the driver work.

I really do not think one could have pushed them down with a tractor loader bucket,

Thanks for the update. It looks like you said you got the small one. Since you now have had experience using it on about a mile of fence (congratulations BTW) do you think it would have been better with a larger unit?

.

 

[BHD]

I would not want any heavier,

and I can not really for see driving any thing but the T posts,

now this time I did not even have the hand pounder on the truck, but when I got it I kind of did a test and it seemed like that the "normal" hit with the hand would drive the t post about the same as with the air powered pounder, so any way, the difference was the air unit keep pounding even if the progress was slow,
but it was such I could take hands off and just let it work. after starting the post.

the ground has been very hard do the lack of nearly any rain here for the last year, we got a little rain in mid September and the top few inches are some what moist, but down about a foot or so, it is very hard,

I did not try this, but my guess is if I would have taken the tractor and loader, 1970 JD 4020 about 9,000 pounds and use the loader on the post I do not think I would have been able to push them in more than about 6 inches and it would have stopped the post and just lifted the front wheels off the ground, and most likely bending up the post not driving it. an any more.

so it is some hard soils,

I would rebuy what I have, I am reasonably sure of, the only reason I may consider the next larger size would be for the extra capacity in size of post, but I guess if I get between a rock and hard place I can use the wood post pounder I made, so I see no reason to consider the larger unit, (my guess the larger unit would hit some harder, which I would think would be a benefit in hard soils, but since It has passed my tests, I am satisfied,

(just an example of how tight the soil is, I drive in one wood post with the tractor mounted driver, and then changed the idea some and went to pull the post, my tractor I know can lift over 4000 pounds on the forks, it could not pull the post or budge it. until then I had not ran in to a post I could not pull)

I would think the 4.5 cfm would run it nicely, for the small unit the 98E Basic, one thing it runs at 75 psi, so the compressor can keep up with it easer, (unlike many tools that run at 90 to 100, the compressor starts before your below the operation pressures,

Runs off of any small air compressor that delivers at least 2.5 CFM at 90 PSI. Runs off air set at 70-75 PSI.

I see the larger units tank more air,

small trick to help smaller compressors, is to hook in an air bubble tank, in to the line, and it will give you more reserve air,

last year I was using a large air hammer, called chipper, with a home made rod driver, and it was about 20 cfm, and had a small compressor but it would drive the post, and the compressor could recover as we moved up to the next post location, now under normal conditions the time that the 98E would drive the post is reasonable quick, (now I will admit these posts I just drive did take a few mins to drive)

one more thing is this is not a large AIR HAMMER,
it a air powered driver,
there is a sleeve that clamps in to post, and the air powers a small piston that pushes up the driver up that is weighed just like a manual pounder,
and when it is raised up the piston reverses and drives the outer sleeve down with the weight , hitting the top of the inter sleeve clamped to the post, driving the post in,
thus it is not a constant pounding of a air piston. like in a air hammer, but a powered driver that work similar to a hand driver, up and down, up and down, up and down. thus the more efficient use of the air source,