Stump plane

[Captain Dirty]

Almost all of the videos I have seen were made by the company that is marketing the machine. As one might expect, rocks are never identified as a problem. I would speculate that the bits are robust enough that a slip clutch or shear pin in the pto shaft or by-pass in an hydraulically driven grinder would trip before the bit were damaged. One of the US manufacturers, I think it is Fecon, states that the bits are easily repaired or replaced in the field, Take that for what it is worth.

 

[TerryR]

I wondered about rocks too. We have lots of them. I have a water line that goes under a rock I couldn't get out with a trencher. But then I wonder how those stump grinders with high-speed wheels do in rocks.

 

[Captain Dirty]

But then I wonder how those stump grinders with high-speed wheels do in rocks.

Short answer: About as well as rotary lawnmowers.

Longer story: My fascination with vertical axis stump grinders is a pipe dream. Prices start around $18K and require a high flow skid steer, 100+ HP tractor, or a several ton excavator, none of which I have. I purchased a 24" horizontal axis "buzz-saw" stump grinder for around $5K.

I live on a hill of glacial till, everything from clay to boulders the size of small cars that was bulldozed by the glaciers. Before I grind a stump, I excavate a bit around it to remove easily handled rocks and identify the location of boulders not easily moved. I will still encounter rocks and, while I have not (yet) broken a carbide tooth, I have sent a golf-ball-sized "pebble" flying 20' despite the mud-flap-like deflector..

 

[TerryR]

That's about what I'd expect.