Hydraulic Post Hole Digger Project

[MOOTS]

Thinking more about this PHD, the only thing I'm wondering about is the distance that the auger is from the end of the loader. Typically the gear box, motor and auger are as close to the SSQA plate as possible, and that's how my HD25 is.

Not saying that this will be an issue, but the further away it is the greater the stress on the loader connection points, and the lower the available downforce from the loader. If the auger binds up on a rock, root or similar, it's going to apply more stress to the loader. Just a thought and not trying to take anything away from this solution. Where I live, rocks are a constant challenge, but for many the ground is like sand.

One of his pictures shows it chained to the fork frame.

 

[John T]

Build complete!! Finished the project today - ground sharp frame edges, mounted hydraulic motor and even though it was wet (torn up turf will become gravel drive this year), I just had to bore a few test holes. Works just fine -.

Nice job, I like it.

I'm not familiar with PH-diggers.... what happens if you hit a huge rock?

Does it stop the auger dead OR does it have shear pins for protection?

I'd love to build one but New England is full of dinosaur eggs....

 

[retiree-urgency abandoned]

Thanks for the compliments and comments.

Kenny, maybe I need to add a few hooks to the contraption - then I could carry the augers to the worksite like dangling earrings.

The hydraulic drive is running off the B3350 3rd function - so probably 5 gph as mentioned above.

McMXi and a few others - this will definitely be a light duty attachment. Most of my fence work is replacing 4" dia. x 6.5" wood posts and rarely redoing a corner of 6" x 6" square - max. depth is probably 3'. In my test drive, I figured out that not using float on the FEL works better. Go slow a little at a time should keep me out of trouble and allow me to react ASAP if I hit something. The hydraulic drive is geared down to a reasonable slow RPM. Am in a valley, so am working with good soil and creek gravel below, but there will always be the occasional lunker.

I like the idea of a shear pin - hadn't thought that far yet, as the ground's too wet to get to work with it. Currently the auger attaches to the drive with a hitch pin (like attached photo). Any suggestions for shear-able hitch pins or just use a grade 2 bolt w/nylock nut?

 

[retiree-urgency abandoned]

As usual, hit post before adding photo.

 

[McMXi]

Thanks for the compliments and comments.

Kenny, maybe I need to add a few hooks to the contraption - then I could carry the augers to the worksite like dangling earrings.

The hydraulic drive is running off the B3350 3rd function - so probably 5 gph as mentioned above.

McMXi and a few others - this will definitely be a light duty attachment. Most of my fence work is replacing 4" dia. x 6.5" wood posts and rarely redoing a corner of 6" x 6" square - max. depth is probably 3'. In my test drive, I figured out that not using float on the FEL works better. Go slow a little at a time should keep me out of trouble and allow me to react ASAP if I hit something. The hydraulic drive is geared down to a reasonable slow RPM. Am in a valley, so am working with good soil and creek gravel below, but there will always be the occasional lunker.

I like the idea of a shear pin - hadn't thought that far yet, as the ground's too wet to get to work with it. Currently the auger attaches to the drive with a hitch pin (like attached photo). Any suggestions for shear-able hitch pins or just use a grade 2 bolt w/nylock nut?

Is a shear pin required for an hydraulically driven pump with 5 gpm flow rate? If the auger hits something that prevents it from rotating, wouldn't the hydraulic pump "dead head" if you continue to press a button for the 3rd function.

A shear pin or clutch for a PTO driven implement makes sense for obvious reasons, but an hydraulic pump will just continue to rotate even if oil isn't flowing through the hydraulic motor on the implement. It's not good for the pump to dead head for extended periods, but I dead head the pump for a second or two every time I angle the hydraulic snow blade to either extreme. Also when I lower the folding cutter.

 

[barts]

A shear pin or clutch for a PTO driven implement makes sense for obvious reasons, but an hydraulic pump will just continue to rotate even if oil isn't flowing through the hydraulic motor on the implement. It's not good for the pump to dead head for extended periods, but I dead head the pump for a second or two every time I angle the hydraulic snow blade to either extreme. Also when I lower the folding cutter.

Any and all hydraulic systems incorporate a relief valve that prevents true "dead-heading"; a positive displacement hydraulic pump that's engine drive will either shatter or blow hoses apart if flow is blocked w/o a relief valve. Obvious, operating for extended periods against the relief is NOT a good idea since it dumps the power of the engine into heat in the hydraulic fluid, but intermittent relief operation is normal and expected.

One form of relief valve that might be suitable here is a. dual crossover relief or cushion valve if the desired relief pressure for the motor is less than the existing relief for the loader.

 

[Kennyd4110]

Is a shear pin required for an hydraulically driven pump with 5 gpm flow rate?

IMHO, no it is not needed.

 

[McMXi]

Any and all hydraulic systems incorporate a relief valve that prevents true "dead-heading"; a positive displacement hydraulic pump that's engine drive will either shatter or blow hoses apart if flow is blocked w/o a relief valve. Obvious, operating for extended periods against the relief is NOT a good idea since it dumps the power of the engine into heat in the hydraulic fluid, but intermittent relief operation is normal and expected.

You stated this way better than me but it's what I was thinking. When I push snow down my driveway and stuff it into a bank at the bottom, at some point the hydraulic pressure used for the HST reaches the relief valve pressure and all forward motion is stopped. The same would happen to the PHD motor where the oil pressure required to rotate the motor and auger would exceed the relief valve pressure and all rotation would cease.