Home made auger for low-flow hydraulics small skidsteer

[vinito]

Got a thread going on my newbie-to-skidsteer advantures. I thought I'd open a new one for my auger adventure. I just now picked this one up off Craiglist and brought it into the garage where my loader is now comfortably nestled too. That's a luxury for me - the garege is usually so full of orphan projects that there is no room at all in there. Anyway, here's what I drug home: It's just direct drive and not much of a mount at the moment. I wonder if it will work this way or if I'll have to add a reducer. Surplus Center has a nice one for pretty cheap if I need it:

I guess the first thing I need to do is hook up the hydraulics and try it out to see how fast the motor spins, then go from there?
My manual shows a spec for the hydraulic pump of 7.2 GPM. I guess that is in the low end, but still in the ballpark isn't it?
Anyway, any advice is appreciated. Caveats, suggestions, criticizms are all welcome.
Obviously the mount will change. I figure I'll make a whole new "cage" for the motor-to-shaft mount since that's a simple box. Then I'll work on how it connects to the machine. Both of those ought to be fairly straightforward I think, as long as I make it all strong enough.

 

[vinito]

Oops. Sure wish I could edit my posts.
As I meant to show, HERE is what I drug home:

 

[Tazza]

Oops. Sure wish I could edit my posts.
As I meant to show, HERE is what I drug home:

Don't be concerned with the speed it turns, what you need is torque to get through the dirt. You really need to get it mounted and running to see how it performs.
The auger i have, has a pretty large drive motor with a reduction gear drive to give low speed bit more power.

 

[vinito]

Oops. Sure wish I could edit my posts.
As I meant to show, HERE is what I drug home:

There's a tag on the motor so I googled for some specs and found: CI/rev = 17.9, minimum starting torque = 2,500 Lb-in continuous & 3,430 Lb-in intermittent, flow = 15gpm cont. & 20gpm int., and then some mechanical specs. for mounting and such.

I found a simple formula for figuring RPM and it gives 231 x GPM / motor displacement which with a 7.2GPM pump comes to 92.9 rpm at maximum possible flow. I figure it might normally be 60% of that considering age of pump and likelihood of engine throttle being set at 3/4 as a comfortable norm (just a W.A.G., but seems plausible). So that means auger RPM will be around 55 if this is correct. So that's abour right for an auger isn't it?
Do you guys think direct drive of this motor will have the torque to do a decent job? Seems like I might have lucked into a pretty decent working window if it's got enough poop to do the job maybe. Am I on the right track?
The gear reducer is close to a 3:1 ratio which would be more torquey, but is that kind of slow for an auger? (between 18 RPM chugging along and 31 RPM at full throttle and luck). I dunno - maybe that's really about right. What do you's guys think? Would I be happier springing for the $170 gear reducer? I've never run an auger before so I could benefit from some experience.
Thanks.

 

[vinito]

There's a tag on the motor so I googled for some specs and found: CI/rev = 17.9, minimum starting torque = 2,500 Lb-in continuous & 3,430 Lb-in intermittent, flow = 15gpm cont. & 20gpm int., and then some mechanical specs. for mounting and such.

I found a simple formula for figuring RPM and it gives 231 x GPM / motor displacement which with a 7.2GPM pump comes to 92.9 rpm at maximum possible flow. I figure it might normally be 60% of that considering age of pump and likelihood of engine throttle being set at 3/4 as a comfortable norm (just a W.A.G., but seems plausible). So that means auger RPM will be around 55 if this is correct. So that's abour right for an auger isn't it?
Do you guys think direct drive of this motor will have the torque to do a decent job? Seems like I might have lucked into a pretty decent working window if it's got enough poop to do the job maybe. Am I on the right track?
The gear reducer is close to a 3:1 ratio which would be more torquey, but is that kind of slow for an auger? (between 18 RPM chugging along and 31 RPM at full throttle and luck). I dunno - maybe that's really about right. What do you's guys think? Would I be happier springing for the $170 gear reducer? I've never run an auger before so I could benefit from some experience.
Thanks.

Thanks Tazza. Our posts crossed. So torque is more important. Sounds like I ought to go ahead and add the reducer.

 

[vinito]

Thanks Tazza. Our posts crossed. So torque is more important. Sounds like I ought to go ahead and add the reducer.

Dangit, I wish I could just edit my posts to add a thought.
Tonight I realized that I could just disconnect my tilt cylinder(s) and hook it up temporarily to test the auger out. It's the same connection as my existing hoses (3/8 NPT). That would be something I could do with zero money in about 15 minutes or so. I'll try that out tomorrow night if I get a chance, then report back.

 

[Tazza]

Dangit, I wish I could just edit my posts to add a thought.
Tonight I realized that I could just disconnect my tilt cylinder(s) and hook it up temporarily to test the auger out. It's the same connection as my existing hoses (3/8 NPT). That would be something I could do with zero money in about 15 minutes or so. I'll try that out tomorrow night if I get a chance, then report back.

That is a good way to test the speed, but you can't really give it a good test with a load.
I'd still give it a go direct drive, then see if you need the extra torque and add the reducer if required.

 

[vinito]

That is a good way to test the speed, but you can't really give it a good test with a load.
I'd still give it a go direct drive, then see if you need the extra torque and add the reducer if required.

True dat.
I didn't have a chance to mess with it tonight anyway. I have a couple tires on this thing that only last about a day - leaking at the bead. So I broke one of them down, cleaned the seat and tire and liberally slathered some sealer on the bead, then put it back together. Had to use the starting fluid trick to seat the bead. Anyway, that took three hours for one tire with my cheapie tire tools.
So I'll shift my focus for the auger onto making it mount to the machine then so I can try it out for real. That shouldn't be too bad, but it will probably be a few days before I can shoehorn it into the todo list.
I ordered the valve, a couple hoses, fittings and a couple quick coupler sets today. I figured I'd go with the flush face ones since that's what is usually on the rentable attachments in case I ever need to do that. It might be here before next weekend. Hopefully that goes smoothly. I can't imagine it should be problematic - all new stuff and I studied what I have pretty carefully so it should all fit up with what I bought. Rightsie-tightsie. About the worst of it is I'll probably have to make a new mounting plate for the larger valve stack, and I might as well make a decent bracket for the auxiliary connectors.
Thanks for the replies. It always makes sense.