Power Beyond and Loader Simultaneous Operation

[aczlan]

Is this to mount the bit to, or to mount to a gearbox? Direct mount, I would go with the larger one hands down. I dont know that the smaller one is setup for the type of side loads that an auger would put on it but the bigger one should be fine with them.

Aaron Z

 

[Thumbs Up Farm]

This is to mount the gearbox to. I don't think the big one has enough torque for direct drive.

My concern with the big one is the rpm. If I use it with a 3:1 gearbox then my rpm is going to be about 50 at max. that means at 20 gpm. So, at what engine rpm is my pump pushing 20 gpm? I don't want to have to run at full throttle just to get 50 rpm on the auger. Also as a rule of thumb, smaller bits need to turn faster.

The small one may be a little weak. It is rated at 5475 in lbs at 2500 psi it will be less than that at my 2000 psi relief setting.

So, if I had a motor with about 5,500 in lbs torque, 300 rpm, 20 gpm 2000 psi and a splined input shaft it would be perfect for my application and calculations.

I realize that there will have to be some trade-off either in time, money, torque, rpm, etc. Just trying to locate the best one.

 

[TomSeller]

50 rpm is too fast for me to dig with. I dig at about 20 or 30 rpm (1/2 to 1/3 rev per sec). I only run up to the higher rpm to clean off the bit outside the hole. You need to rev up your engine to get your pump rated GPM.

 

[aczlan]

This is to mount the gearbox to. I don't think the big one has enough torque for direct drive.

It is rated at 9700 in-lbs. continuous which translates to ~808 ft-lbs. That should be enough per J_J's earlier post.
That is 2.5 times the 3800 in-lbs. torque rating of he Northern Tool one: NorthStar Hydraulic Earth Auger — 270cc Honda GX Engine | Auger Powerheads, Bits Extensions| Northern Tool + Equipment and almost three times the 3300 in-lbs. rating of the "Ground Hog" Ground Hog ? HD99 Hydraulic Earthdrill
That is also well over the rating of any of the units sold by Little Beaver ( Towable Hydraulic Earth Drills | Little Beaver Inc. ) which are common rental units in this area.

My concern with the big one is the rpm. If I use it with a 3:1 gearbox then my rpm is going to be about 50 at max. that means at 20 gpm. So, at what engine rpm is my pump pushing 20 gpm? I don't want to have to run at full throttle just to get 50 rpm on the auger. Also as a rule of thumb, smaller bits need to turn faster.

Generally speaking, it will be at 540 PTO RPM.

Aaron Z

 

[J_J]

This 1 1/2 in taper hub should match up with the White motor above, and the hub is less expensive that the 1 1/4 in taper.

5 BOLT WHEEL HUB 1-1/2" TAPERED W/BRAKE DRUM

Your engine is turning at max speed to get the 20 GPM on the pump if it is direct driven.

540 PTO rpm is not usually max rpm.

You only need fast speed on an auger if you are in a hurry.

You don't need max engine rpm to run the auger.

The torque should be about constant.

If you use the auger and down force at the same time, then the motor relief will be the limiting factor.

You can set the motor relief the same as the loader

Your loader valve will relieve at the tractor set pressure.

 

[Thumbs Up Farm]

50 rpm is too fast for me to dig with. I dig at about 20 or 30 rpm (1/2 to 1/3 rev per sec). I only run up to the higher rpm to clean off the bit outside the hole. You need to rev up your engine to get your pump rated GPM.

Thanks that is great info! That helps a lot!. I had thought that 50 might be to fast but kept seeing that speed on web sites. That make the choice easy.

 

[Thumbs Up Farm]

It is rated at 9700 in-lbs. continuous which translates to ~808 ft-lbs. That should be enough per J_J's earlier post.
That is 2.5 times the 3800 in-lbs. torque rating of he Northern Tool one: NorthStar Hydraulic Earth Auger — 270cc Honda GX Engine | Auger Powerheads, Bits Extensions| Northern Tool + Equipment and almost three times the 3300 in-lbs. rating of the "Ground Hog" Ground Hog ? HD99 Hydraulic Earthdrill
That is also well over the rating of any of the units sold by Little Beaver ( Towable Hydraulic Earth Drills | Little Beaver Inc. ) which are common rental units in this area.


Generally speaking, it will be at 540 PTO RPM.

Aaron Z

Also great info.! With the larger motor AND the 3;1 gearbox. The torque at the auger with 2000psi relief will be 1,940ft lbs and the max rpm 53.3 I have some experience with some of those small units, they are pretty much worthless in 90% of the places on my farm, too many roots and rocks. With more power and some down pressure from the loader, I should be able to do some serious digging even in tough soil.

Seriously considered going with this one though.

45.6 CU.IN. | Wheel Motors / Wheel Hubs - Quadra Trading Corp

 

[J_J]

That motor should work, and even has brakes.

Just don't expect the motor to start turning until the pressure is built up to 275 psi and fully released at 475 psi.

Your torque will be less than advertised at 20 GPM and even less if you reduce engine rpm.

 

[aczlan]

Also great info.! With the larger motor AND the 3;1 gearbox. The torque at the auger with 2000psi relief will be 1,940ft lbs and the max rpm 53.3 I have some experience with some of those small units, they are pretty much worthless in 90% of the places on my farm, too many roots and rocks. With more power and some down pressure from the loader, I should be able to do some serious digging even in tough soil.
Seriously considered going with this one though.
45.6 CU.IN. | Wheel Motors / Wheel Hubs - Quadra Trading Corp

If a gearbox will run you an extra $300, I would go direct drive. Less stuff to break that way.

Aaron Z

 

[Thumbs Up Farm]

That motor should work, and even has brakes.

Just don't expect the motor to start turning until the pressure is built up to 275 psi and fully released at 475 psi.

Your torque will be less than advertised at 20 GPM and even less if you reduce engine rpm.

I thought from the earlier post that the flow (gpm)didn't affect the amount of torque, only the rpm? Can you give me your calculations of torque and rpm on that motor based on my system. (2000 psi 20gpm)?

I would definitely like to go direct drive. That would make my fabrication job easier and reduce the parts that could be broken. Just want to make sure I have adequate auger torque to dig in my location, otherwise it is wasted effort. Gearboxs can be purchased for less than $150 and they already fit standard auger bits on the outlet end.