Any odds on these Rock Tongs working?

[Luke'sScreenName]

I've been spending lots of time "harvesting" glacial till granite rock to reclaim pasture. I've been building very crude granite walls mostly just because I need to go SOMEWHERE with all this dang stone.




I would like something more precise to place the medium size (75-500lbs) rocks. Using the grapple or tree/post puller is cumbersome. My backhoe has no thumb .

So I spent a few hours today with scrap iron to attempt a set of rock tongs to hang off the FEL or maybe even the backhoe.

I give it a 25% chance of moderate or better success. I'd appreciate any input on the design as I expect to to do some revisions. (Yes, I know the welds stink).

I hope to try it later in the week.

 

[Farmer2750]

Small rocks maybe but they look a little light duty for bigger roxks

 

[George2615]

I can't tell from the pics what the thickness of the angle is. Looks like 1/8" or possibly 3/16". Not going to be strong enough to pick up a 500 lb boulder. Might be OK for <100 lb. rocks. Always good to make something out of scrap to try first.
If that doesn't work out you should get some 1/2" steel and build a fixed or adjustable thumb for the BH.

 

[Luke'sScreenName]

I can't tell from the pics what the thickness of the angle is. Looks like 1/8" or possibly 3/16". Not going to be strong enough to pick up a 500 lb boulder. Might be OK for <100 lb. rocks. Always good to make something out of scrap to try first.
If that doesn't work out you should get some 1/2" steel and build a fixed or adjustable thumb for the BH.

It's a combo of 3/16 and 1/4 cold rolled. It's what l had. I was also conscious of making it too heavy to easily manhandle. :confused3: Not sure where the correct compromise is but it's definitely not overbuilt lol.

 

[Oldpath05]

If low on funds, might consider an adjustable-mechanical thumb on your backhoe, those tongs are probably good up too 200 lbs max, but what you need is some clamping power that a thumb will give. Best combo would be grapple on FEL and power thumb on backhoe, but you'd have to sell some rocks to pay for it.

 

[George2615]

If low on funds, might consider an adjustable-mechanical thumb on your backhoe, those tongs are probably good up too 200 lbs max, but what you need is some clamping power that a thumb will give. Best combo would be grapple on FEL and power thumb on backhoe, but you'd have to sell some rocks to pay for it.

He already has a grapple. Maybe just needs more practice with it.

 

[4570Man]

I would build both sides like the right side and then use a hydraulic cylinder to close it. Use your grapple third function to power it. If you are low on funds you could probably temporarily borrow hoses and a cylinder from the grapple.

 

[muddstopper]

My 2cents, which might not be worth even a penny, are. I dont think the tong approach, which is great for wood and softer materials, isnt going to work very well with rock. Reason being is that the tongs wont bite into the rock or one side might take a bite and the other side not, resulting in a condition where you actually drop what ever you are picking up. Not something I would feel comfortable with if I was placing very heavy stones. To work, I think you would need more clamping force than just the weight of the rock against the tongs. adding a hydraulic cyl with you angle iorn approach probably wont work well either simply becasue you would most likely end up bending the angle. Since you already own a backhoe, I think I would spend my time and money building a thumb for the backhoe bucket.

 

[Mendonsy]

I'm inclined to agree with mudstopper. I think it is going to be difficult to get enough grip on those rocks to carry them. You might want to lower the pivot point of your clamp so that the top lever arm is at least as long as the grip side to get more leverage against the rocks.

 

[N2DFire]

The "Rock Tongs" concept is very much a viable one (and even made/sold commercially) so I would suggest doing some Googling on Rock Tongs, Rock Jaws, Rock Grapple, etc and look at some designs to borrow ideas from.

There is at least one old thread here on it I found from Google searching that has several designs & comments on it.
http://www.tractorbynet.com/forums/attachments/76294-rock-jaws.html

The very last post in the thread looks like an interesting rig & something that might interest you.

The biggest drawback to the gravity / weight driven tong concept is the rounder & smoother the rock - the harder it is to "pinch" with just 2 tongs (like log tongs) - for something like that I think you're on the right track by having a wider fork type tong for one side - might even work better with both sides and having them interlace when closed (and a lot simpler to fabricate than a 3-jaw design)

Best of luck & keep us updated on how the project develops.