Limiting depth of post hole digger

[LS Tractor Owner]

I have only used one or two man augers in the past, this is my first 3 pt PHD. I have watched numerous videos and read numerous posts. I thought I was well prepared to dig my first hole....wrong. I'm using a 9" auger, standard length. Tractor is a 25hp SCUT.

I had the throttle about 22-2300 rpm, dropped the 3 pt a little and the auger dug right in. I lifted it after approx 6-8 inches in, lowered it again trying to do the same, but it screwed in about 8-10 inches. When I immediately tried lifting, but it just stalled the tractor. Restarted the tractor and tried at full rpm at 3000. It just continued to dig in. When it went to full depth, (couldn't go any further, gear box at ground level), it just excavated all the dirt and freed itself up, about a full 48" deep.
The dirt is very dry clay, no rocks or roots at all. I was actually surprised at how easy it screwed into the ground.

I only have to go 24" (30" max) deep on the holes so, my questions:

1) Can I set up a mechanical stop on the 3 point lever to only lower the 3 point to a predetermined position or will the auger continue to just pull it down? I'm hoping that once it hits that "stop point", the auger would just free itself up like it did in the first attempt.
2) What throttle setting should I use? It seemed that at a lower throttle setting, it didn't dig in as fast, but I had no power to lift.
3) I have looked at purchasing a "compact" auger which is only 32" long, but really don't want to spent $140 for another auger if question #1 would work.

Any help would be very much appreciated. Thanks

 

[EddieWalker]

I've seen metal frame built around the auger on YouTube when I had the same problem. What brand of auger do you have? Instead of building the frame, I just try harder to only go down in small bites at a time. Before buying the Country-line Auger from Tractor Supply, I never had that issue. Now it's a real concern. Fortunately for me, I have a backhoe and I can run a chain from the top of the auger and pull it out with the backhoe. The hole isn't as clean, but it's easier then turning the auger backwards with a 48 inch pipe wrench and a six foot pipe over the handle.

 

[jaxs]

I do as Eddie does but my tractor is considerlby heavier than your Scut. I fear if you adjust the stop on lift,the auger will pull the front of your tractor off the ground.:shocked:

 

[mapper]

Fill the loader with gravel or sand to counter balance the pull of the anger. Take a small bite and see if it clears itself rather than screwing in deeper.

 

[newbury]

Just take SMALL bites with the auger.
After you've backed one out you'll appreciate going in slow.

 

[kthompson]

I use phd seldom but do not run a high rpm for more than one reason. Roots (we have very very few stones here) can be major issue if near trees. If the auger runs down too deep due to rocks or roots you "might" be able to stop the pto and cut off the tractor and back the auger our a couple or so of turns and then with pto off try lifting the auger and it might be free. If so try engaging the pto and at very low rpm run pto to clean off the auger.

 

[Fallon]

Use your 3pt lever to inch it down literally an inch at a time. If you go to deep to fast it corkscrews in & you have to unscrew it out with a 5' pipe wrench or dig it out with a shovel. Slow feeding means the auger can pulverize the dirt in the hole rather than self feed in.

I never ran my 3pt PHD over half throttle. Way to much vibration & chances of things going wrong before you could blink, much less clutch. A PHD is one of a handful of 540 PTO impliments you run at a lot less than 540 rpm.

 

[BrokenTrack]

I have only used one or two man augers in the past, this is my first 3 pt PHD. I have watched numerous videos and read numerous posts. I thought I was well prepared to dig my first hole....wrong. I'm using a 9" auger, standard length. Tractor is a 25hp SCUT.

I had the throttle about 22-2300 rpm, dropped the 3 pt a little and the auger dug right in. I lifted it after approx 6-8 inches in, lowered it again trying to do the same, but it screwed in about 8-10 inches. When I immediately tried lifting, but it just stalled the tractor. Restarted the tractor and tried at full rpm at 3000. It just continued to dig in. When it went to full depth, (couldn't go any further, gear box at ground level), it just excavated all the dirt and freed itself up, about a full 48" deep.
The dirt is very dry clay, no rocks or roots at all. I was actually surprised at how easy it screwed into the ground.

I only have to go 24" (30" max) deep on the holes so, my questions:

1) Can I set up a mechanical stop on the 3 point lever to only lower the 3 point to a predetermined position or will the auger continue to just pull it down? I'm hoping that once it hits that "stop point", the auger would just free itself up like it did in the first attempt.
2) What throttle setting should I use? It seemed that at a lower throttle setting, it didn't dig in as fast, but I had no power to lift.
3) I have looked at purchasing a "compact" auger which is only 32" long, but really don't want to spent $140 for another auger if question #1 would work.

Any help would be very much appreciated. Thanks

Just take a small piece of wood...like a round piece of firewood (not split) that is the proper length, and set it under one of your lift arms on the 3 point hitch. As the auger gnaws its way downward, the lower lift arm hits the block of wood and stops at a 24 inch deep hole.

Just make sure the stick of wood is not so big that it is too heavy to move about, but not so small in diameter that it tips over easy...it should stand up on its own.

 

[LS Tractor Owner]

I've seen metal frame built around the auger on YouTube when I had the same problem. What brand of auger do you have? Instead of building the frame, I just try harder to only go down in small bites at a time. Before buying the Country-line Auger from Tractor Supply, I never had that issue. Now it's a real concern. Fortunately for me, I have a backhoe and I can run a chain from the top of the auger and pull it out with the backhoe. The hole isn't as clean, but it's easier then turning the auger backwards with a 48 inch pipe wrench and a six foot pipe over the handle.

I have a 'dirty hand tools' model 100. I didn't say that I was going to get the auger at TSC, but now I noticed that they were selling the same augers. I too have a backhoe, but it's naturally off the tractor when using the PHD...LOL!

 

[747driver]

You are running the PHD at to high of a rpm. As Fallon said, I hardly ever go above 1000 rpm to run the auger. The higher the rpm the faster it will corkscrew down....hoping you don't hit something that will cause the auger to twist and snap or bend something. I go down inches at a time in rocky and hard soil and pull the auger up to clean out.

 

[LS Tractor Owner]

I thought of something last night, when I was trying to control the depth of drop of the 3 point, I don't think I adjusted the flow control down to slow the drop, allowing the auger to dig in. I'll try that.

I also like the idea of blocking the 3pt lower arms, I'll try that too.

I was trying to control the depth but it would dig in faster than I could lift it back up. May be the drop was just too fast.

Anyway, I'll play with it and try the different ideas.

 

[Gary Fowler]

I thought of something last night, when I was trying to control the depth of drop of the 3 point, I don't think I adjusted the flow control down to slow the drop, allowing the auger to dig in. I'll try that.

I also like the idea of blocking the 3pt lower arms, I'll try that too.

I was trying to control the depth but it would dig in faster than I could lift it back up. May be the drop was just too fast.

Anyway, I'll play with it and try the different ideas.

You don't need to adjust the rate of drop valve, just lower the 3 PH lever a bit at a time (don't drop it all the way down) so the auger starts digging in then raise it back up to clear the dirt, then lower the lever a bit at a time so the auger lowers back into the hole slowly and stops lowering. Inch the lever down a bit at a time to get some contact to the fresh soil and only allow the auger to lower a few inches before raising it out of the hole to clear the dirt.
Also, you don't need to be more than 1500 RPM for the auger to work.

Just in case you do auger in and cant raise it, it is much easier to use a pipe wrench to turn the PTO shaft backward to "unscrew " the auger than it is to try and turn the auger itself. It takes a lot more turning, but the PTO shaft can be turned using just an 18" pipe wrench without a cheater pipe. Once freed up a bit by turning the PTO shaft, you can then use the wrench to turn the auger shaft itself.

 

[majorwager]

All great arguments for hydraulic PHD. Mine: mounted to the FEL, while folks are fooling around w/ an inch at a time, are you serious?, My job is finished. .Ability to forward/reverse against a stubborn stone/rock generally loosens it. Easily dig hole and set twelve posts an hour, a comfortable pace.


EDIT: good point, use my PHD on little ford, 7-1/2 GPM. works great. Use it on LULL, operates in intermittent range of pump capacity, outstanding results. Even the little guy below would be more productive than the nonsense in this thread.


photo would load?

 

[Tractorable]

Ok, but most folks don't have a tractor with enough hydraulic flow on the FEL to operate a hydraulic PHD.

 

[LS Tractor Owner]

Yea, would be nice to have a larger tractor and a hydraulic PHD. I'm just grateful that I was able to finally afford to get a SCUT. Did a lot of digging footers, post holes, all by hand. Oh, let's not forget about shoveling and raking out driveway stone by hand..... Anybody want to donate a bigger tractor and attachments? Well, I'm just going to 'fool around', but have fun doing it...

 

[majorwager]

Clarification,
Bought Stihl drive head and two augers, used from rental yard $200.
White RS Hyd motor, 2 hoses, power beyond valve next to loader valve $ $300.
Misc iron in shop, simple frame, short pieces 2 x 5 tube to slide over pallet forks. Hardly a huge investment. To date, 400+ fence posts installed

 

[Fallon]

I had a 3pt PHD for my old 32hp (25pto) L3200. I made some mods to it including 200lbs of extra ballast over the gearbox. It would dig pretty decent, but you still had to baby it & inch it down. It ran off with my old tractor.

I got a hydraulic 3rd function on the loader of my new L4060 along with a hydraulic SSQA PHD. 40hp & double the weight. It has a hydraulic flow of 9.something gpm & relief of 2,500psi. 10gpm & 2,500psi translates into under 14.5hp (probably less with all the extra plumbing losses). So my fancy new tractor & PHD have 10hp less avalibe than my old L3200 & 3pt PHD. I can feel that every time I use it. But the new setup has a couple thousand lbs of downpressure via the loader & I can reverse it at will. Despite being under powered it will dig at about the same net speed, but kills my neck less while doing it.

I never jammed my 3pt unit once in 10 acres of fence post holes. Got close a few times, but never corkscrewed. I jam & stall my hydraulic PHD on every hole, especially because of being able to lift the front of the tractor for downpressure. But having hydraulic reverse means I free it in a second or 2.

Basically a 3pt unit of ran right will do 5-10 acres of holes just fine. The $2-4k for a hydraulic PHD isnt going to be worth it for that scenario vs a $600 cheap 3pt one. Once you start doing more than that or doing it commercially or semi-commercially like I do now, hydraulic comes into own. If you do get one, match it to your flow. Real skid steers flow a LOT more than a tractor & most SSQA PHD motors are matched to a much higher flow.

 

[jmc]

I started paying more attention to the pilot drill tip geometry when my mass-marketed unit would not penetrate dry, hard clay. (in regular soil it works great) On mine, the very tip of that cast steel spiral point is not a cutting point but rather a bald hemisphere that kinda polished a shallow hole in hard clay. I made a mental note to, before the next job, grind some grooves in that tip so it would cut instead of wallow.

After reading some of the experiences on this thread, I wonder if the spherical tip on mine is intentionally inefficient and acts as a brake on the penetration rate. After all, it does work great in normal moisture. Long shot, I know, but it would be interesting to see pictures of the tips on some overly aggressive units described here.

 

[skipmarcy]

I run my tractor around 1200 rpm for phd and just regulate my 3pt drop with the control, pulling up to clear the dirt often. I also found out years ago it makes it so much easier to start holes if I just take some little effort and use my hand post hole diggers to cut down just an inch or two deep - the auger starts so much easier and no walking all over the place - I get the hole right where I want it that way.

 

[Oldoak]

I run my tractor around 1200 rpm for phd and just regulate my 3pt drop with the control, pulling up to clear the dirt often.

That is exactly how I operate my Danuser phd. Controlling the drop with the 3pt hitch lever, not the valve under the seat, and definately at low rpms. Until reading this thread I never realized so many people had so much trouble with a 3pt phd. But I do notice there are various designed tips on the assortment of augers that are out there which would act differently.

Must have drilled a couple of hundred holes over the years in red shale type hardpan soil here in ne PA without the problem discussed in this thread.