Shear (pin) frustration

[BillyP]

I have a tiller that uses an 8.8 grade shear pin (metric). That same 8.8 would be right at a grade 5 SAE.

 

[jinman]

So...
Does your hydraulic PHD ever get stuck or stalled? What does it do when you hit a rock? Does the hydraulic motor just stop? I suspect it's also pretty expensive. I've seen them, but never considered them to be a viable option since I don't dig postholes for a living.

 

[uhmgawa]

</font><font color="blue" class="small">( So...
Does your hydraulic PHD ever get stuck or stalled? What does it do when you hit a rock? Does the hydraulic motor just stop? I suspect it's also pretty expensive. I've seen them, but never considered them to be a viable option since I don't dig postholes for a living. )</font>

It will just stall while the relief valve hisses until you
let up on the spool. The nice thing about hydraulic augers
is they are reversible allowing you to back out of the bind
and try again without losing your seat. Some can also be
mounted on loader/backhoe buckets allowing more flexibility
compared to 3PH/PTO augers.

Worth the money if you are doing a fair number of holes
and/or in rocky/root-laden soil. But you need to get
that hydraulic power from somewhere and turn it back into
rotary motion. I wouldn't be surprised to find a net
loss of 20% or so which may be an issue for some.

 

[jinman]

</font><font color="blue" class="small">( they are reversible allowing you to back out of the bind
)</font>

Thanks for the info. That reversing feature sounds really handy.

 

[grandad]

Hi, Glenn. My wife and I just visited family in Fredericksburg, and from walking their land, I can certainly understand how you might snap a shear pin or two digging post holes down there! If fact, I'm thinking a charge of dynamite might come in handy some of the time! But, aside from that, you sure have a beautiful part of Texas to call home!

 

[GlennT]

Icat--I'm using the Leinbach 7300 with a John Deere Model 670 (16 HP PTO). That's about as minimal as you can get. I have a 9 inch auger and dig each hole 42 inches deep. That puts the head of the auger right in the top of the hole. But, OH BOY, do you have to be careful. The tractor barely has enough power to pull the auger out of the hole and I don't dare let it auger in more than 6-8 inches before before pulling it out and clearing it. Also, I don't want to put excessive stress on the tractor or the auger head. I had one horrible experience a few months ago when the auger was at full depth in clay and I could neither pull it out nor manually reverse the rotation to free it. I suspect the bit was lodged in a root or a rock. I spent an entire afternoon with a spade, clamshell digger and iron bar digging another hole alongside the auger so that I could free it. What a rotten day! I don't mean to complain, though. My Model 670 is a great all-around tractor and this kind of work is really asking a lot of it.

 

[icat]

Thanks for the reply Glenn. When we were digging holes for our foundation with my cousin-in-law's tractor (Ford 3910), his auger would literaly stop when we tried to break the surface. Had to bring in my 5.5 HP Honda two man auger to "break the crust" and get down to 36 inches. I like the idea of the tractor mounted auger, but after that day I wondered if the two man auger wasn't the best bet. I don't know if the auger bit was dull on the tractor digger, but the 2 man punched right through. With it though, you've got a maximum depth of 36" or so. I'd like to be able to go a bit deeper on occassion.