converting a PTO post hole digger to hydraulic drive

[ddbackhoe]

65 RPM sounds too slow...12% of 540. I'd want it to spin fast enough to fling the dirt off the auger when you bring it out of the hole.

If you reverse direction, the dirt usually falls off.

 

[texasranger556]

Actually, that sounds about right. Model G2/4 | G24 | PTO Auger | Danuser is running about a 3 to 1 gear reduction. That puts things at well under 200rpm (cuz I can't math). And personally I can tell you 3pt PHDs get dam scary if you are running them over half throttle. So that puts you easily in the under 100rpm territory.

Coincidentally the chart at Model EP6 | Danuser lists from 36 to 90 something RPM.

I was thinking OP wanted to drive the existing post hole digger gearbox with the motor, so 65 RPM through a 3:1 reduction would be way too slow.

 

[polemidis]

CH47,

Torque is a product of gpm x pressure.

I disagree to that. Torque is not relevant to gpm. Its analog to the pressure, and analog to the displacement of the motor.
gpm do not affect torque (a measurement of rotational force) . It affects the final rpm (power) or how fast the job will be done. Not the force.

Torque is what he needs to be able to make the hole through the tough ground and rocks
gpm is what he needs to make it faster.

He can get almost whatever torque he wants by defining the motor displacement. Larger displacement motors output higher torque (in exchange for slower rotation)

Check out the brochure http://www.danuser.com/sites/default/files/FormNo_3403A_EP_Brochure_0.pdf
Reading the charts you can see that the gpm only affects the rpms.

 

[radios1]

I disagree to that. Torque is not relevant to gpm. Its analog to the pressure, and analog to the displacement of the motor.
gpm do not affect torque (a measurement of rotational force) . It affects the final rpm (power) or how fast the job will be done. Not the force.

Torque is what he needs to be able to make the hole through the tough ground and rocks
gpm is what he needs to make it faster.

He can get almost whatever torque he wants by defining the motor displacement. Larger displacement motors output higher torque (in exchange for slower rotation)

Check out the brochure http://www.danuser.com/sites/default/files/FormNo_3403A_EP_Brochure_0.pdf
Reading the charts you can see that the gpm only affects the rpms.

true, Horsepower = Pressure (psi) x Flow (GPM) http://web.applied.com/assets/attachments/779D4407-D2AE-6FAA-7DA1CEDE2268977B.pdf

 

[majorwager]

pole..

You did not read my post. I stated GPM x pressure. Given the pressure as a constant, it will turn so slowly, it will be almost worthless. Not only will it fail to shake the clay/dirt residue off the auger upon raising, but it is not only TORQUE that loosens rocks and soil, IT IS THE SPEED in which the auger tip makes contact, that loosens rocks. IT requires momentum.


I have drilled hundreds of holes w/ a hydraulic auger. Perhaps YMMV.

 

[majorwager]

Hydraulic torque formula below

 

[radios1]

Hydraulic torque formula below

that's horsepower, not torque, I see where this is going, and I tried, but I'm out of this now.. goodbye..