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.

 

[J_J]

6369 in lbs or 530.75 ft lbs

Input the cu in of the motor, and input the pressure of the tractor hyd system.

Result is in, in lbs.

Burden Sales

Speed is a time factor, just gets the job done quicker.

Motor displacement is set.

Pressure potential is there, but the motor develops the pressure.

If you want to see if the motor is developing the max pressure, install a hyd gage in the hyd system.

When the motor is working at full pressure, then the torque is there.

If you have half pressure, then you have about half torque.

 

[Thumbs Up Farm]

Using the calculator link with my new choice motor for direct drive and my system info I get;

1270 ft lbs of torque and 101 rpm. These numbers work for me except that rpm is too fast for a 12" auger. Might be good for using say an 1.5" bit for drilling holes for t-posts in rock

My question(s): At what engine rpm does my pump produce the 20 gpm? Is there a standard or typical engine rpm? If, for example, the engine/pump rpm has to be at 1200 to produce 20 gpm and that translates to 101 auger rpm, then I would need to run at about 600 engine rpm to get the auger down to 50.5 rpm. Correct? If so, that may be barely idle speed which could kill my engine if I max out the pressure load.

Maybe a flow reducer of some sort, if that exists.

Your thoughts on engine speed, auger rpm, torque, etc. please!!

 

[aczlan]

20GPM is with the engine wide open (~2000 RPMs). Its a linear relationship, so ~1000 RPMs will put out ~10GPM.

Aaron Z

 

[J_J]

Tractor Data says your engine rpm is 2000.

If you entered the Surplus calculator correctly, then it is what it is.

You can either reduce the engine rpm or reduce the flow using a flow control valve.

Add one of these inline with the motor and use the lever to set the speed.

With this valve, you will not need a relief across the motor.

3/4 NPT HYD FLOW CONTROL VALVE W/RELIEF RDRS175-30

http://www.surpluscenter.com/_MoreSpecs/as9-064-xx.pdf

 

[Thumbs Up Farm]

Thanks guys, that works perfect!!
Tractordata info is incorrect as far as flow. They say 20 gpm, but when I looked up my pump by model number, its says 17 gpm. That means at (assuming 2000 engine rpm) I get 86 auger RPM. So at 1000 engine rpm I get 43 auger rpm with 1270 ft lbs of torque.

Gentlemen, we have a winner!!

 

[Redneck in training]

Ideally I would want the auger to spin constantly with constant feed/torque while digging and applying down force.

After reading about the two spool version of the prince valve I was under the impression that the pressure going to the PB would be completely cut off if using either of the loader valves. If I understand what you are saying, then that is not true.

If I am understanding this correctly;

As long as I don't put full pressure on the loader the PB/auger would still turn although slower/less pressure depending on loader pressure. It would basically be a balancing act to get rotation and down pressure by me controlling the feed rate for the drill. When I stop applying down force I would get full auger force.

If that is the case then I think this would work because I could but pressure on intermittently with the loader which would hold with the weight of the tractor on the bit until it reached depth.

That should also work for extracting the auger if it gets stuck.

I had considered using a motor spool but decided that I would want to use the same spool for the grapple.

I am not expert on hydraulics. Having this disclaimer out of the way here is what I think:
The thing about cylinders is that they take fluid only when they move. While motors (while rotating) have always flow through them. So if you have the motor on the first valve the flow will go to the return line until you move another valve. Then it will go to that valve and in example cylinder. When the cylinder reaches stop the flow stops. If you keep the second valve in between when some flow goes to the return and some to the cylinder the motor will slow down because it will have a back pressure the flow will be restricted. But the cylinder will maintain certain force.

 

[J_J]

If the tractor flow is say 10 GPM.

If you activate a lever to move a cyl, you are providing 10 GPM flow for that time the cyl is moving and then it tries to pass through the relief valve.

Now, you are causing a hyd motor to run at full flow, and then you push the cyl second spool lever about half, using half flow or 5 GPM. Yes the motor will slow down using a tandem spool valve and that 5 GPM for the cyl will pass through the relief valve until you release the lever.

As soon as you release the cyl spool lever, the motor regains the flow and back to original speed.

 

[J_J]

Thanks guys, that works perfect!!
Tractordata info is incorrect as far as flow. They say 20 gpm, but when I looked up my pump by model number, its says 17 gpm. That means at (assuming 2000 engine rpm) I get 86 auger RPM. So at 1000 engine rpm I get 43 auger rpm with 1270 ft lbs of torque.

Gentlemen, we have a winner!!

There is a flow meter and pressure test setup that is used just to test pumps.

It ain't cheap, but very useful.

wdchyd made a video showing the use of the flow meter test set.

Perhaps he will post it for you to watch.

That way, you can see exactly what you have for hyd.

 

[Thumbs Up Farm]

Ok educate me a little further. I have two choices here that will work in my application and budget. It would appear that one of these has a brake and the other does not.

45.6 CU IN WHITE DT SERIES HYD WHEEL MOTOR

45.6 cu in WHITE HYD 712750W8A31AAAA MOTOR W/BRAKE

There also appears to be other ports on these motors other than the two hoses for the spool. Does the brake require seperate plumbing? What is the third port on the side of the motor with no brake?

 

[TomSeller]

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.

I dig fairly slow, being cautious as I am, in case I hit a big root or rock I want to have more time to react. With being able to reverse it is not as much of an issue but I kept that habit from the old 3 point PTO augers I grew up with.

I think the high RPMs you see posted on websites are for the tree planters and people like that. Where speed and Skidsteers are the norm. You need some extra spin to clean the auger but nothing more than 1rev/sec or so. When I figure my time to replace a fence corner, I don't even figure in the auger time. It is a couple of minutes at the most per hole.