Post driver build - Could I please pick your brain for post-driver ideas?

[denrep]

I'm thinking about building a driver for sinking H-beam or pipe into the ground.
Maybe 6" beams or 8" pipe to be sunk about 4' in average soil conditions, nothing too rocky or solid.

The driver could be stand-alone, or it could be an attachment mounted to a forklift, backhoe, wheel loader, excavator. . . whatever. Power can be mechanical, hydraulic, air, maybe even steam :laugh:

I'm thinking that the simplest system would be to lift a very heavy weight and then repeatedly drop it on the beam's head.
But how?

A lift cylinder with large dump ports to allow for rapid fluid/air exhaust as the hammer drops?
Or mechanical disengagement from the lift cylinder, allowing the hammer to free-fall?
Or forget the cylinder and go back to the simple lift line on a winch drum?


Thanks in advance for your ideas.

[mla2ofus]

Take a look at the 3 point hitch post drivers for farm tractors. They're hydraulic and work very well. They will drive 6" pointed wood posts. They wouldn't drive 4' tho, I don't think they have that much travel. I guess you could make a spacer to set between the driver hammer and the top of whatever you're driving once the driver ran out of travel.
HTH,
Mike

[500HpSilverado]

I have a Shaver HD12 . I think your going to find this is one of those things you decide to buy. Ours has a cylinder that raises the rams and it uses some pretty serious springs to drive the post in about 8-10 cycles. I will look for some pics on my computer and post them if I can track some down. We run ours for our vineyard on a little JD 5525. Im sure there are youtube videos of them, they are fun to play with the first few times, then it becomes work. but it is always better then setting them by hand!

[dabar39]

My idea would be to look for an old well drilling truck for cheap. The mast and winch would be strong enough to hoist the size beam you mention and the cat head with a slide hammer to drive them in the ground.

[G3farms]

I would have to agree with silverado, I also have a shaver post driver and they work great. You can definately get 4 foot into the ground since the 3 point hitch will raise and lower the entire unit. You are limited to how long of a post you can get under it though, I drive cedar post that are in the 7' to 8' range and 8" to 10" in diameter three feet or better in the ground. Just have to sharpen the end first with a chinsaw.

I think it does good in the red clay we have around here.

G3

[farmersamm]

Hey, long time no see, my fault

If it's for fence, bad idea. (my fence woes will follow in another post)

First off , if you have to keep the iron plumb, it's a guess at best. Second, the contact with the soil causes rust.

The barrier line between wet, and dry is where the damage happens. AND ALL YA PILE DRIVER DOODS, I KNOW WHAT YOU'RE GONNA SAY.

I had some idiot drive in some corner posts. All being said and done, the mechanism was pretty cool. Belt driven off of the tractor PTO, with a clutch that activated the raising mechanism (holding the weight), and releasing it at the end of the cycle. lIke a trip hammer. If I ever let the bast*ard back on my place, I will be sure to take a pic.:rolleyes:

[imc188222]

We have a king hitter post driver. Here is a link to their site. http://bobericksonequipment.com/products/king-hitter.html I would be more than happy to take pictures of it if you would like. It has been great and there is not much limitation on how far it will drive them. The first time we tried it we drove a 6" round pressure treated post through 2' of frost without sharpening the end.

[lugweld]

My vote is for steam...

[redcoupe]

i built these for a living...for driving guardrail post wood and steel in the ground....go to fergusonhp.com and look at their stuff...i dont work there anymore but can help in anyway that you need so PM me if you cant see the pics to copy off of....

[Sandy]

i built these for a living...for driving guardrail post wood and steel in the ground....go to fergusonhp.com and look at their stuff...i dont work there anymore but can help in anyway that you need so PM me if you cant see the pics to copy off of....

They drive some of those guard rail posts in pretty deep too don't they? I've heard that some may go 12 feet.

[denrep]

Thanks for all the comments.
I did a little measuring and pondering today. I'm still thinking about a build, before I write a check for one.

Alfred said I'm making it too complicated - "You just need to lift a heavy hammer, guide its drop, and then, KABOOM!"

So okay, here's a prospective guide:
40720

And could one of these be a hammer?
40722

Or maybe something like this, 738 lbs:
40721
Sliding between a pair of beams, guillotine style?

To a point, I think that the manufactured units are a bit of a compromise, because they're forced to conserve steel.
I'm not trying to save steel; when this baby hits I want ‘em to feel it in China. :laugh:

My biggest hang-up is the fluid exhaust. I think that the fluid return path has to be huge, to dump the fluid without hampering the hammer drop, or risking cylinder damage. Air would sure be easier to rapidly exhaust. A free falling hammer would solve the exhaust issue, but then the cylinder has to take a slow ride to retrieve the hammer.

And anyway, how far does a hammer have to drop to reach optimum hitting velocity?

Good Luck

[DSW]

Must be nice to work at a place where they just have money lying around...:laugh:



I was thinking something around the lines of a hydro hammer with a post guide. Instead of one big bang, lots of little thumps.

[Sandy]

And anyway, how far does a hammer have to drop to reach optimum hitting velocity?

Well in the real world outside the scientific vacuum that would be what they call terminal velocity. Big heavy object like you've got there it would take a mile high tower before wind resistance had much effect. :laugh:

But here's a calculator a guy could plunk in distances you think you can get or want and fudge from there.

http://hyperphysics.phy-astr.gsu.edu/hbase/Flobi.html

[denrep]

Thanks Sandy, That's a handy calculator.

Hmm. . . 250lbs dropped 3 feet, hits as hard as 500lbs dropped 1.5 feet.

According to the calculator, a Buick Electra dropped from 330 feet should drive the post in one hit. :laugh:

[Sandy]

Thanks Sandy, That's a handy calculator.

According to it, a Buick Electra dropped from 330 feet should drive the post in one hit. :laugh:

Make sure our favorite canine isn't in the Buick when you do the drop test.:laugh:

[Sandy]

250 lbs would be more managable than 500 lbs. What did the mandrel weigh on the old water drilling rigs? What were they, about 3" to 4" and eight feet long??

[MarkBall2]

How about something heavy & driven by a cam & toggle? You could drive it off the PTO. Lots of smaller taps to drive it in, like a finish nail. Then you could control plumb easier.

[Boostinjdm]

Look into how they drive in those wavy pieces of steel to hold back river banks and such. They re-did a bridge here awhile back and it looked like they had a giant vibrating deal hanging from a crane to drive them in. I think the crane just moved the piece into place and let it dangle straight while the vibrator did all the driving. Don't know how that would handle a solid post, but I think it would work good for an I beam.

[imc188222]

As far as exhausting the fluid goes. The driver we have uses a cable run through a block and tackle of sorts so that the ram moves say an inch and the weight moves a foot. That way, the ram moves back fast enough for the weight to free fall and can pick the weight back up for successive hits to be pretty fast. I'm sure there is a video of a king hitter post driver on the web somewhere. Pretty simple design. We looked at a lot of different ones before buying this one.

[RancherBill]

DenRep, I'd use a hydraulic system. There is more to a post pounder than just lifting the weight.

I have rented one of these (http://www.wheatheart.com/_uploads/Wheatheart/Products/142_Wheatheart_-_Post_Pounder_V18_web1.pdf) for $130/day and I know they will put those posts in with no problem, It has a ton of extra features to position and manipulate the post to get them in perfectly straight exactly where you want them. I was amazed at the "great" job that we did with no experience. It was all the machine - not the operators.:):)

I looked at it from the view to "I could copy that" and I came away going it's not worth it. They are super heavy duty to pound big posts. There's a heck of a lot of stress when the hammer hits.

PS definitely wear hearing protection.

[denrep]

For anyone wondering why not just buy a driver, it's not so simple as to just rent or buy a driver for this job. The driver will probably have to push post sizes and lengths outside of the typical commercial driver's specs and reach. Next thing is that three-point hitch mounting is out, so the mount will have to be a custom piece too. And the work is not like fence job out on the open prairie, where many posts can be driven in a long day, to control rental costs. Besides, if we just bought everything, what would we post on WeldingWeb? Politics? :p

I did turn up a hydraulic vibrator removed from a cable trencher's plow. I haven't played with it yet, not sure if it may be usable for post driving.

I'm sort of convinced that the builders of commercial drivers are hampered by weight limitations.

So with Alfred's motto of: "Don't force it, get a bigger hammer" in mind, tonight Alfred and I performed a quick heavy-hammer feasibility study, to get a feel for how much weight has to drop how fast, and how far, to drive a beam home.

Here's the prototype hammer, 927 lbs, plus four sticks of 7018 :laugh:
40762
It's inverted here for welding, during the test run the square block will hang down, as the striker.

We chained the "hammer" to a forklift carriage. The forklift has a restrictor which limits carriage drop speed, so there will be no "Demon Drop" rides today. :laugh:

8' tall beam in compacted sandy soil:
40763
The mast was tilted so that the "hammer head" was level.
A few gentle strikes to start the beam, and then a check and adjustment for plumb.

Once the beam was started plumb, I let it have some hard hits; the beam stayed plumb.
Short rapid hits seemed to be more effective than long drops.

I drove the beam into compacted sandy soil seven feet.
The slowdown started at about four feet.
40764
Rock solid, and as plumb as would be expected from a student driver.
I may piggyback another 800 lbs on the hammer to see what that does.

Now... Does anyone have an idea for a decent post puller. :laugh:

I plan to digest the study results for a few days as I think over some post driver options.

Thanks again for the suggestions. :waving:

[Boostinjdm]

you said you found a vibrator...what happens if you rest that hammer on top of the beam for downward pressure, and then vibrate the beam?

[Sandy]

I did turn up a hydraulic vibrator removed from a cable trencher's plow. I haven't played with it yet, not sure if it may be usable for post driving.

Most of those that I was familiar with back in the day were just gear driven off centered weights (think crank shaft with no rods) and an intended Vibration Per Minute of around 700 or so. They were made to break up hard soil or fracture rock in the forward progression via an up-n-down action. Dunno, I like the 'whammo' mentality of the big weight.

Short rapid hits seemed to be more effective than long drops.

I'll guess that, in this case, acceleration is limited by the fork lifts drop limits therefore there was little noticable difference in real impact between longer or shorter drop distances. So in this case nearly as much work done in a short drop as a long drop do to a lack of increased acceleration so the more IPM the quicker the work is done.

Sounds good right now. Later it may change. :D

[Sparky8370]

You should just buy one with all that money laying around everywhere.

[the Q]

a capstain winch to run your weight would work. simple frame to guide the weight and post, and a capstain to line up the post and drop the weight.

[BlindViper]

what state are you in?
where are these blocks at? I am thinking anvil
http://www.weldingweb.com/attachment.php?attachmentid=40722&d=1256612217

[Scott Young]

don't forget to hard face your hammer face.

[Tractapac]

Denrep, I'll post some pics of a Kinghitter we have. Good to see that imc188222 has one, too. (Made in NZ - but don't tell farmersamm) Ours is an older model and is innovative in that having a 15 foot mast, you can lie it down to rest the top in a support by the front wheel of the tractor, for road use. Helps keep it clear of power lines etc. Later models have a folding mast where the top section folds down.
The maker's site is: http://www.fairbrotherind.com

40905
6'6" post 8" dia. rammer has been moved out 9" from it's "home" position to align with desired post position. Also the diagonal ram angles the mast in or out at right angles to the tractor.
40906
Cap resting on post top, has a spike to locate it. Vertical ram is the lifting method for the monkey. Three pulley sheaves on the ram and three below. 55 feet of wire rope. Ram is single acting. (and fairly quick too!) Dump to tractor reservoir is via the orange/pink hose.
40907
Right hand plough arm is hydraulic also for positioning. Gives fore and aft movement to mast base. Large central ram is the one that lies the mast down for transport. Ahead of that is another ram that gives fore and aft adjustment at the top of the mast.
40908
Here you can see the transport ram and the fore and aft adjustment ram and also the hydraulic plough arm. You can see the spike under the post cap. Also the post cap has a UHMWPE top to it to prevent metal to metal contact from the 550 pound monkey.
40909
10 posts at 3.6m (12 foot) centres and then an 8m (26 foot) gap to the next set of ten.
Fairly straight row. With the spike in the post cap, you can control the direction of driving reasonably well. Part way down, I disengage it all from the post to check for plumb and then re-engage it and push or pull wherever to correct any drift. None of these deadmen or the strainers that go in above them are pointed and the rows are all quarter rounds and they're nigh impossible to control if you sharpen a point on them.

If you'd like any more info or pics or measurements just ask.

[Tractapac]

And now for something completely different!

Here's an adaptation of a Bobcat for post hole boring, post ramming and shelter pole erection. Kiwi ingenuity again.

40910
Note the duals for traction. The set up shown is for post hole boring but it also accepts a retractable rammer to allow it to drive under the kiwifruit canopy (6 foot) and then put the rammer mast up and replace any damaged posts. It can also act as a jib when they're erecting tall shelter cloth windbreaks.

One photo hasn't uploaded, I'll do that shortly.

[Tractapac]

Now for the missing photo.

40911
Removing one set of drive wheels and adding the castor at the rear maintains the maneuverability of the Bobcat but doesn't tear up the ground like a skid steer.
It's driven from a seat above the front left wheel.
Another twist in case it helps.

[DSW]

Denrep that sure looks like your pup in that pict. Not only do you have money just lying around the shop, you send your dog to Kiwi land to check out possible options!

[burnandreturn]

Where I live it is impossible to use a ram device because of the terrain. Banks and ditches and such. A tractor with post hole auger is useless. First you can't get to most of the places I need to build fence. Second the ground is to rocky. The auger gets stuck. I tried a 15,000 dollar hydraulic auger on my excavator. It would only dig about fifty percent of the holes and be stuck by a rock. So I had a special chisel made for my hydraulic hammer for my excavator. The chisel is four feet long! I can now put a hole anywhere in 10 seconds. I also have a 8 inch square flat foot for the hammer. I can drive most posts in with the flat foot. The excavator goes where I need. I just drive along the side of the line and swing over to put a post in. There is some skill needed to get the posts straight but after maybe 50 posts I got real good at having them plum and inline. And if one is not just right I can just yank it out and try again. The long chisel was expensive to have made but worth every penny. I only use it on my own property or my friends. It is a two man job though to do it right.

[denrep]

Sorry I haven't been back, thanks for the replies and pictures. Lots of good ideas.

Where do I start?
First things first, let's get the money thing cleared up :laugh:
The problem with "all that money" lying all around, is that it all carries the same serial number!

The dog - Pac's dog sure does look like kin. I sent a pup to Honduras once, maybe he kept right on going. :laugh: The black muzzled mongrels are sure a fine breed.

The blocks - Sorry BlindViper, can't get off the blocks for your anvil project. The blocks are a premium around here. Check with Oldiron2 and his "free" thread, in his area bigger pieces than that fall out of the sky! :laugh:

No real progress since the test.
I've been thinking about different options, mostly a "monkey" on an H-beam.
I was hoping to go all hydraulic, and direct acting, no cables, ropes, chains.


Thanks again

[jackh]

personally id stick to the old school way of driving them by hand. much more precise than letting the hydraulics go at it. ive heard of them getting off a bit and being driven in too far to correct when doing it with the machine. doing it by hand is much more precise but a pain in the ***

[MrLeadMan]

[QUOTE=denrep;327620]Maybe 6" beams or 8" pipe to be sunk about 4' in average soil conditions, nothing too rocky or solid.

jackh I've driven zillions of those steel t-posts over the years with a maul or driver but uhhh....I ain't about to attempt no six inch H beam or eight inch pipe old school by hand.

[G3farms]

When Dad bought our farm he was putting in new line fence. Cedar post that were sharpened on the end and driven in the ground with a 16 pound sledge. He would stand on the back of a trailer to get high enough to drive it in the ground. There was a young fella helping him (not me I was just a few years old) and kept wanting to drive a post in the ground and Dad would always tell him no because he was too little. Well Dad finaly gave in one day, little fella grabbed the sledge, reared it back over his head to drive it home in on lick, missed the top of the post...............sledge swung down and went under the trailer with little fella still holding tight to the handle, it jerked him off of the trailer and head first under it. Needless to say he did not want anymore of the post driving.

I guess he learned something at the "old school" lol

G3

[imc188222]

Did I catch a hint, from another post, that you have finished the post driver and are using it? Can't wait to see pics of it if that is the case. :)

[denrep]

This'll be kind of disappointing, but I bought a production model hydraulic post driver and attached it to a rough terrain fork lift, but it just doesn't have the "punch" for the big posts, although it works fine for smaller ones.

Then I built a couple of simple drop hammers... lift, release, and KABOOM! The post gains a few inches. But after about a dozen big posts the job was snowed out. I'll dig up some pictures.

I would like to build the "guided missile" a large "monkey" weight riding an H-beam carrier. I'm still stuck on the hoist mechanism design. I'm sort of leaning towards a hydraulic motor for hoist, and a clutch that could release the weight for a true free drop.

Good Luck

[Brad Blazer]

I'm pretty sure the Shavers use a long single acting hydraulic cylinder and a very free-flowing exhaust. The cylinder diameter is pretty small - you want to maximize speed and minimize exhaust flow. A 1" cylinder will lift about a ton in a straight lift. Check out the Shaver HD12. They talk about driving unsharpened RR ties. Might be a good size to copy.
http://www.shavermfg.com/DrSp.html
http://www.shavermfg.com/movie.html

[burnandreturn]

Why couldn't you build a diesel piston type of pile driver? If you really want a hammer type of driver it might be your simplest solution.

[taylorlambert]

A friend of mine that has a welding service built one to drive poles for his dock building and repair business. Its the trip type like an older hydraulic one he repaired for a fence builder. He mounded a knuckle boom on a barge and put the hammer on it. He took a tilt cylinder off a forklift to make a set of tongs on the bottom to pick up poles off the deck of the barge and hold them till it gets a few licks on it. He has a 500 pound weight on a boxed rail and a long 2 inch cylinder on it works it up and down. The rod is about 1.250 and about 6 or 8 feet long. He can pick and set a 20 foot siz inch pole in in about a minute. It will drive one down to the hard pan or rock in about 10 hits. The small piston can shoot up and retract pretty fast. A cylinder will retract a bit quicker because the rod takes up more space in the head end of cylinder. He can tap a pole in by using the cylinder and rocking the lever forward and backward. The way his trips it has a spring loaded square rod that fits into a tube on top of the cylinder. Its shaped like a striker in a door latch and when its run down it catches in a square hole intop of the weight. When it raises up in the last 2 inches of the rods stroke theres a plate cut like a wedge cam that hits a roller on the side of the striker that pushes it out of the catch in the weight. It works real slick. He also has an add on extension to make the hammer reach out of the bottom of the frame. He has used this to bust concrete piles and concrete decked walkways.

[denrep]

I'm pretty sure the Shavers use a long single acting hydraulic cylinder and a very free-flowing exhaust. The cylinder diameter is pretty small - you want to maximize speed and minimize exhaust flow. . . .

BB, They say imitation is the sicerest form of flatery. :laugh:
Maybe I'll wander over there and look, but I've been trying not to taint my thinking.
I'm with you 100% on the flow issues.
Thanks

Why couldn't you build a diesel piston type of pile driver? If you really want a hammer type of driver it might be your simplest solution.

B&R, I would love to build such a driver, but it just seems like too much R&D to be practical. I wouldn't know where to start with the math, or fuel injection, cylinder size, intake, exhaust, or anything. Any ideas? I could come up with a DD unit injector, and 92 cylinder kits. Would that be big enough?


. . .He has a 500 pound weight on a boxed rail and a long 2 inch cylinder on it works it up and down. The rod is about 1.250 and about 6 or 8 feet long. He can pick and set a 20 foot siz inch pole in in about a minute. It will drive one down to the hard pan or rock in about 10 hits. The small piston can shoot up and retract pretty fast. A cylinder will retract a bit quicker because the rod takes up more space in the head end of cylinder. He can tap a pole in by using the cylinder and rocking the lever forward and backward. The way his trips it has a spring loaded square rod that fits into a tube on top of the cylinder. Its shaped like a striker in a door latch and when its run down it catches in a square hole intop of the weight. When it raises up in the last 2 inches of the rods stroke theres a plate cut like a wedge cam that hits a roller on the side of the striker that pushes it out of the catch in the weight. It works real slick. . .

Bert, That's a lot to chew on! I would sure like to see a picture of this jewel. It sounds like the cylinder trips out to allow the monkey to free-fall, and then chases it after the drop for another lift. Is that right? That would eliminate the choking return oil rush, and the chance of the cylinder taking a destructive hit from a bottoming or misfire.

Thanks for all the ideas. :waving:

[kenklingerman]

Now for the missing photo.

40911
Removing one set of drive wheels and adding the castor at the rear maintains the maneuverability of the Bobcat but doesn't tear up the ground like a skid steer.
It's driven from a seat above the front left wheel.
Another twist in case it helps.

GENIUS:cool2:

[taylorlambert]

Ill sure get some pics of the whole set up even the barge. Its simple hammer he coppied an ag version that he mounted for a mutual friend of ours on a Bobcat. Its real simple and the small diameter cylinder will shoot up quickly. It only need 2 doble acting circuits to run plus the prime mover. Miss firing its kinda rough on it he deliberalty mis fired it when it was sitting in fron of his shop. and it shook things a bit but it was a big out fit. His original barge had a folding tower and an old PCU/CCU cable unit off an old Cat D4. It was hookedto a toyota car motor and transmission. THey used it to drive poles but it wasnt as veritale as the new machine. the next time Im at the lake Ill get a few pics of it. I can also get some pics of the agunit the other friend has.