Best attachment for digging out rocks?

[Frankenkubota]

Backhoe with a thumb ... or .. I once built a rock "grabazoid" ... not sure what they are called, but it's a scissor device that you drop over the rock, and the harder you pull the harder it grabs, quite amazing what this thing would pick up with just the most tenuous of grips. Basically an "X" with the bottom side of the X some fingers, and the top side hooked up to chains ... as you pull up the X closes on the rock, the harder you pull, the harder it grabs. I ended up building a few for local contractors that needed to lift blocks of cut stone, the mechanics are somewhat counter intuitive .... but the lifting force ends up being multiplied by the chains hooked up to the top of the X and exerts tremendous pressure on the object being lifted. Not useful for digging the rock out .. but way less frustrating than trying to grab a rock with a thumb.

That’s a good idea! Like one of those Chinese finger traps.

 

[Dataway]

Yep, that's the idea. The first prototype was attached to an engine hoist that fit in a socket on the chassis of a stripped Toyota Land Cruiser. I was flabbergasted how well it would grab things. I'd dig the rocks enough with the BH to get a grip on them, then I could pick them up and carry them with the Toyota creation ... then set it down where you want it, have someone pull the "fingers" apart to release them, also very easy. Then started making some for local stone workers .. with pivoting "shoes" on the lower fingers that had hard rubber riveted to them ... they were picking up 1000 lb pieces of cut stone with them.

The chain length between the top legs is the key ... the shorter it is, the more clamping force is created, but the less throat width you can have as the lower fingers won't open up as much. If you can get the fingers under the rock you can get away with a longer chain. With a short chain I'd lift stuff that would swear the fingers would slip off of ... but no, I could bound across the property with the rock dangling and it would stay put.

Pretty easy to build ... use two or three angled fingers on the bottom of the X like you were building a grapple ... hinge in the middle can be a bit more trouble as it should be a centered hinge not two adjacent bars with a pin through them, top arms of the X about 18" long with provisions to hook up a chain. Not sure what I did with mine .... probably cut it up to build something else. Biggest pain was moving it around .... you'd be dragging it somewhere and it would stop you short as it tried to grab anything in reach and hold on.

 

[civilian]

Backhoe with an Hydraulic Thumb worked GREAT for meView attachment 666734View attachment 666735
I dug out some big rocks digging a new Leach field for my home.

Been there, done that like your first picture. One had the front wheels of the B26TLB off the ground trying to lift it. Had to finally skid it out of the hole. Only the top of the rock showed up in the driveway. Dug it out before spreading gravel. Jon

 

[RSR]

Update:

I ended up buying a subsoiler from everything attachments. It has worked extremely well at loosening up the rock-ridden clay soil so that it can be dug up.

I have to make multiple passes, from multiple directions, but it loosens everything up enough that I can come back with the grapple to pick out the larger rocks, and then dig out the soil and smaller rocks.

 

[dickhob]

Stump bucket - near the price of bucket spade and won't tear up your bucket. Keeps force centered on loader.

View attachment 665275

How do you like this bucket? I don't have a need to get out large stumps. I mostly want to transplant saplings under 6" and dig out 2x basketball rocks. i've been looking at the Titan bucket which I think might be a bit sturdier.

I would appreciate your comments.

Dick