Question about hydraulic post hole digger
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JRP
Platinum Member
Two questions. What is a swing cylinder, and do you have a hydraulic valve already on your tractor?
If you dont have rock then low torque will only make you drill a little slower, but still much faster than a hand digger. Back to the bearing, without the axial bearing you might drill 100 holes instead of 5000. Just a wag.
So far I have drilled less than a dozen holes.
I think the used wheel motor for the well rig cost $100 off ebay.
Enjoy your project.
If you dont have rock then low torque will only make you drill a little slower, but still much faster than a hand digger. Back to the bearing, without the axial bearing you might drill 100 holes instead of 5000. Just a wag.
So far I have drilled less than a dozen holes.
I think the used wheel motor for the well rig cost $100 off ebay.
Enjoy your project.
That's an excellent thought. I keep looking new, i never even thought to look used. The only downside would be having to look up manufacturer specs for each one i find to see if hydro and torque specs will work. But still might be worth a look.
As for the swing cylinder. The loader hydro's will be able to control the tilt of the auger bit from front to back. I want to have another cylinder built into all of this to control the swing from side to side. I don't want to have to rely on a second person showing up to help dig holes. This way it can all be done from the drivers seat. Rather than the unit dangling from the pin. And it will be reversible and selectable to the different pin slots depending on which side of the tractor i need it to be on.
I don't have any extra hydros at the moment. I have several projects lined up that will require one or more extra circuits. So that's another thing this project is waiting on is funding for all of this as well. My original project was adding 3rd function for a grapple. I've had most of the framework built for quite some time now. And the valve has been sitting on my bench for a month. I need to take the time to mount the grapple back on the bucket and measure so i can order the ram and hoses that i need and it will be done. At that point i will have the groundwork laid for this post hole project as well. Then all i need for hydraulics is the motor and a couple of hose whips
As for the swing cylinder. The loader hydro's will be able to control the tilt of the auger bit from front to back. I want to have another cylinder built into all of this to control the swing from side to side. I don't want to have to rely on a second person showing up to help dig holes. This way it can all be done from the drivers seat. Rather than the unit dangling from the pin. And it will be reversible and selectable to the different pin slots depending on which side of the tractor i need it to be on.
I don't have any extra hydros at the moment. I have several projects lined up that will require one or more extra circuits. So that's another thing this project is waiting on is funding for all of this as well. My original project was adding 3rd function for a grapple. I've had most of the framework built for quite some time now. And the valve has been sitting on my bench for a month. I need to take the time to mount the grapple back on the bucket and measure so i can order the ram and hoses that i need and it will be done. At that point i will have the groundwork laid for this post hole project as well. Then all i need for hydraulics is the motor and a couple of hose whips
JRP
Platinum Member
You might consider that perhaps 95-99% of post hole diggers use gravity to keep the auger point down. If you make a slight adjustment in augerCG possible you should have a plumb auger bit. This will greatly reduce cost. My photo shows two swivel pins 90 degrees apart. K.I.S.S.
The arc movement of the bucket travel is such that for a straight plumb hole you need to back up and go forward as you drill. Most of us ignore this without issue. Some bobcats have a vertical travel lift arm geometry.
The arc movement of the bucket travel is such that for a straight plumb hole you need to back up and go forward as you drill. Most of us ignore this without issue. Some bobcats have a vertical travel lift arm geometry.
I understand what you mean. I'm planning to just leave my tractor in neutral to allow for the arc of my FEL downward travel and leave the rest of the slop alone. As far as the additional cost, it will only be one additional hydro circuit,valve, and cylinder. I plan to eventually add this for other implements anyway. Thats what I was referring to earlier in the thread as the reason for this project taking longer than any others is because of this initial startup cost. I will eliminate one of the pin mounts that you have, using the bucket tilt instead. And the other pin mount will not swivel by gravity, but rather by my control of the cylinder attached to the auger assembly. I know its probably overkill and there will probably only be very few instances where I will actually hook it up this way. But at least the functionality will be there. There have been several times when using a 3 point mounted post hole digger that I have wished I could better control the side to side sway of the bit. Whether it was due to some slop in the hitch/PHD/auger attachment, or because the tractor wasn't able to park perfectly level with where the hole was going, etc.
Bison
Platinum Member
Looks good! Any idea the specs on the motor you used?
I was just browsing through ebay. There are a LOT of hydro motors on there. Not many of them are specified as wheel motors though. Visually they look mostly the same except for the output shaft. But beyond that I have no clue if they would be even close. It may be worth the extra money to just buy a new one and know what I'm getting. Not sure... Any thoughts anyone?
I was just browsing through ebay. There are a LOT of hydro motors on there. Not many of them are specified as wheel motors though. Visually they look mostly the same except for the output shaft. But beyond that I have no clue if they would be even close. It may be worth the extra money to just buy a new one and know what I'm getting. Not sure... Any thoughts anyone?
JRP
Platinum Member
Of the 35 " hydraulic wheel motor" on ebay, only one is cheap at $150, and it looks very rough. No good deals right now.
Kinda what i was thinking. If i alter the search to just Hydraulic Motor, tons of results. But I have no clue if any of them will work. And they are still mostly around the $100-$150 range. Probably may as well buy new and know what I'm getting and not risk wasting money on a motor that won't even turn the bit
Bison
Platinum Member
I have no clue as the identification plate is to damaged to read. I got this motor at a scrap yard for free.
It is a roller motor and has a 1/14" keyed shaft and it makes max 85 rpm being fed by a 25 gal/min pump at 2250 psi.
It works fine with the 12" auger bit as long as i take it easy as the bit will stop turning when i put to much down pressure on it.
It could be that the motor is somewhat worn which might be the reason it was in the scrap yard to start with but so far so good.
I drilled another 30+ holes this summer without an issue.
