Hydraulic auger selection - rpm vs torque

beesnstuff · Mar 19, 2015

Hi there,

I have narrowed down my search for an auger drive for my JD 5083e:

EP15, 15.9 GPM, 2828 psi, 2650 ft-lbs, 52 RPM
EP20, 15.9 GPM, 2828 psi, 3484 ft-lbs, 40 RPM
Pro 1025, 15.9 GPM, 2828 psi, 2892 ft-lbs, 48 RPM
Pro 2035, 15.9 GPM, 2828 psi, 3683 ft-lbs, 38 RPM

The above torque and rpm have been recalculated based on Danuser specs for other pressures and flows.

My question is: Which one would be best for drilling holes in rocky subsoil? Highest torque? Is 40 RPM not too slow?

J_J · Mar 19, 2015

Which ever one you can afford.

Any one of them will work.

Here is some Bobcat auger stuff and data.

http://www.bobcat.com/publicadmin/getFile.do?id=4576

beesnstuff · Mar 19, 2015

J_J said:
Which ever one you can afford.

Any one of them will work.

Here is some Bobcat auger stuff and data.

http://www.bobcat.com/publicadmin/getFile.do?id=4576

Thanks. I know I'm over analyzing it, but I always do this. Spreadsheets for everything I buy

In this case, I'm leaning towards Pro 2035. 40 rpm should be ok for controlling it and fast enough for me. I know any of them will drill in sand and top soil, even if compacted. But around here it is rocky gravel. I did a fence around my 1ac garden by hand, 6 posts a day, two guys, for two weeks. And I don't want to buy an auger and end up breaking stones by hand. It is fun to do one, but now I have to do ~800 posts. I need a solution were I can do 25/day by myself. My thinking is 3600 ft-lbs of torque should push or break any rocks that are in a way. Maybe I'm wrong, not sure.

J_J · Mar 20, 2015

One option would be to rent a auger with a rock bit and see what it can do.

Depending on the rock, you may go through many bits before your job is done.

Carbide teeth are tough and expensive.

jenkinsph · Mar 20, 2015

I have a PA30 auger on my 110tlb with similar flow rate, IIRC my rpms are about 40 to 50 on the bit. I also chose the higher torque over speed for the same reason. This seems to work through the rock well in most cases but I have stalled the bit on occasion but have been able to make all of the holes so far. I was concerned about the low speed but after using the auger it does drill the holes quickly with the down pressure applied. The main disadvantage to the low speed is it is too slow to sling the dirt off the auger, so you have to pull out of the hole and tilt the auger to clear it. So far I have used a 6" and 12" bit with mine but larger shrub bits are available. The Frontier PA30 is available in ssqa or backhoe quick coupler configurations.

beesnstuff · Mar 20, 2015

jenkinsph said:
I have a PA30 auger on my 110tlb with similar flow rate, IIRC my rpms are about 40 to 50 on the bit. I also chose the higher torque over speed for the same reason. This seems to work through the rock well in most cases but I have stalled the bit on occasion but have been able to make all of the holes so far. I was concerned about the low speed but after using the auger it does drill the holes quickly with the down pressure applied. The main disadvantage to the low speed is it is too slow to sling the dirt off the auger, so you have to pull out of the hole and tilt the auger to clear it. So far I have used a 6" and 12" bit with mine but larger shrub bits are available. The Frontier PA30 is available in ssqa or backhoe quick coupler configurations.

Do you use dirt or rock bit? Or something in between?