Hydraulic flow - Auger purchace

[Irie808]

1999 Case 1845C auxiliary hydraulics state 16gpm @ 2300psi
I am kind of focused on the Eterra auger but still open i guess.
2 models to chose from 2500 or 3500.
2500 - gets me 1400 ft. lb. torque at 2300psi and 82rpm at 16gpm. (This is on the higher side for this model of 7-17gpm)
3500 - gets me 1760 ft. lb. torque at 2300psi and 64rpm at 16gpm. (This is mid to lower end of for this model of 10-25gpm)

Rep. recommended the 3500 for the torque and falling in the middle of the flow chart. I started to think about my machines age + using the loader arm to push down force on the auger might make the flow less than 16 gpm. I guess the question is should i worry about my flow being affected for the reasons mentioned or any others you can think of? Also any thoughts on rpm's in general? I plan on running a 9" bit in mostly dirt but some random rocks for 5-6" round posts.
Opinion are also welcome on auger size for application and the tips ie. carbide teeth or maybe straight up rock bit and be done with it, $$ though.

Ira

 

[crane operator]

I've dug a whole lot a holes with a tractor PTO 3 pt. mounted auger. I used to install white vinyl fencing at a place I worked.

That said- I haven't dug very many with a skid loader. Spinning the auger faster is usually no help. The slower the better. Less likely to break stuff when you hit a rock or tree roots.

 

[KSSS]

You are right, as you use the loader arms for downward pressure you will lose some rotational speed and torque. However you will learn to auger deeper more slowly and then allow the auger to pickup speed as it cleans out the hole. Then you repeat the process until your at your depth. I had no problem digging holes with my 1840's back in the day. It wont be as fast as the newer machines with more psi and gpm but it still gets done. I would also suggest the 3500 series in your case. The first attachment I bought besides a bucket was a Lowe 1650 post hole auger. I still have it and it still digs holes even with large 2' bits. I would hate to guess how many holes that attachment has dug in the past 25 years, but it is a lot. They still make that auger, I would look at one of those as well.

 

[Welder Dave]

Yeah, you don't have to go too fast with an auger on a skid steer. I usually drilled holes at about 1/2 throttle. It's more important to lift the auger up occasionally when drilling(to clean the hole and material from the auger) so it doesn't thread itself into the ground and get stuck. A stuck auger, especially if you use an extension to get 6' or deeper is not a fun experience.

 

[Mark13]

As the others have said I wouldn't worry to much about needing to spin the auger fast. I have a Bobcat 30c auger which is one of their low speed, high torque power heads. I commonly run it on idle with my Tak TL230 and that machine is only 18gpm at 3k psi at wide open. I've been digging 24" diameter, 7ft deep holes with it this last week and I hardly ever get above half throttle.

 

[Larpy]

Fast is not smooth......being smooth is fast. Lower speed, patience and the 3500 will do the trick!

 

[Irie808]

Thank you all for your opinions on the auger drive, seems like they are all on the same page, which is great!

 

[Jbullfrog]

The auger should pull itself in, you don't have to push it in. You do have to hold it back occasionally.

 

[JBrady]

The auger should pull itself in, you don't have to push it in. You do have to hold it back occasionally.

This is how I do it to. I drill most holes just a little above idle with as little weight on bit as possible. Makes for a gun barrel hole. If I hit a rock, I'll put a little more weight on it to see if it will punch through it. Usually if you get to the point your front wheels are two feet off the ground and wide open throttle, you're not going to get through it. In the case of fence post, just move over a foot or two and try again. I've had a few times I had to have a hole (building barns) in an exact spot. I've rented rock bits with some success, but also had to use jack hammers, backhoes, etc. ugh...rocks.