# How do stump grinders work in rocky soil?



## redprospector (Jan 27, 2005)

I've been concidering adding a stump grinder to my equipment, just wondering how they hold up in very rocky ground? The mountain range I am in is basicly limestone with a little topsoil scattered around. Would I be shelling teeth all the time, or do they hold up to rock pretty well?
I've never used a stump grinder, so I'm dumb as a box of rocks about them. That's why I'm asking you guys.
No one else in the area has one, and I've been told that is the reason.
If they won't hold up I can think of a lot of other things I'd rather waste money on (like a fast saw).
Any help would be appreciated!!


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## Lumberjack (Jan 27, 2005)

The teeth wont like it at all but its doable. Your best bet would be to use slightly dulled teeth and decrease the speed of the cutterwheel to save the teeth. Its a catch 22, but people in rocky areas get paid to take the damage.


Limestone is pretty soft in the realms of rock. Is it gravel or in big chunks? It might be possible to use dulled teeth (rounded edge holds up better) and power through it.


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## redprospector (Jan 27, 2005)

It's big chunks! Usually around the base of a tree it's broke up some, but there are still baseball size and better. Sometimes under a stump you'll find one the size of a truck.


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## Lumberjack (Jan 27, 2005)

What machine are you considering? Or what price range? 


Is their anyone else in your area that grinds stumps?


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## redprospector (Jan 27, 2005)

I don't know much about stump grinders, so I don't know what I'm looking for yet. If I can figure out how to make one work in the rocks I'll know more about what I'm looking for.
As far as price range, I need to do more research on how willing my customers are to pay for stump removal (they all want it, but will they be willing to pay?). 

There is no one else in the area that has a stump grinder, They all say it won't work but I'm not convinced of that.

Any suguestions as to what might work would be appreciated.


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## alanarbor (Jan 27, 2005)

If you're going to be the only one in the area, then it sounds like you could pretty much name your price, factoring in the abuse your equipment will take. I might suggest Greenteeth for your application, because they are a really quick change cutter, and you'll be going through a lot.

www.greenteeth.com


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## Lumberjack (Jan 27, 2005)

Well i would recommend the Rayco RG50 or super 50. But they run around 30k dollars. Most people in the mountains charge 3x4 times what we charge. As for the rocks hurting the machine, i dont think it will damage anything but teeth. Limestone is alot softer than carbide.

The RG50 is self propelled and all hydraulic. That means you can vary the cutterwheel speed and the engine speed seperatly (like motor at full power but cutter wheel slowed down to save teeth. You could speed up the wheel when grinding out the stump part then slow down at the bottom and on the roots.

Check them out at www.raycomfg.com


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## redprospector (Jan 27, 2005)

Thanks for the links guy's. Now my education begins. I've got a lot of research to do now.
What do you charge per hour for grinding stumps. I only ask as a guide to use (factoring extra teeth), to see if people in my area are really interested.
A lot of the jobs I do are marked by the State Forestry, and there are literally hundreds of stumps we leave on just about every job. I may be on to something here.


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## alanarbor (Jan 27, 2005)

we usually run at 150.00/hr 1/2hr min. I've found I can do a 30" oak stump 4-6" below grade, no major surface roots to chase in about an hour, set up, grind, clean up (raking up No chip hauling) seeya later. In rocky soil like your talking about I'd probably shoot for about 225/hr. Another key piece of equipment is a big chainsaw. When someone leaves a stump really high, it's faster to flush it off, and chuck the slab in the truck than grinding it all. AS for the grinder i'd choose, I'd go for the RG50 with the backfill blade. You can get in into tight spots but its got the power for good size stumps.


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## redprospector (Jan 27, 2005)

Alanarbor, 
Thanks, I'm going to start talking with some folks tomorrow and see if they really want to get rid of those stumps or not. My old Husky 288 should be big enough, till something bigger comes along. 
What little hardwood we have around here is Gambel Oak (not too big). Most of what I'd be grinding is Ponderosa Pine, Spruce, Balsam, White & Doug fir
6" to 36". From the sounds of it, I should be able to blow through them pretty quick (time will tell).


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## P_woozel (Jan 27, 2005)

I'm not an advocate of running slightly dull teeth, that just means they will be really dull that much faster, charge accordingly for your stumps. Buy a grinder and sharpen teeth. I do it and it is definitely worth the time. :umpkin:


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## Stumper (Jan 28, 2005)

Redprospector, Welcome to the forum. A few things from someone who has ground stumps in the Rockies. Carl (lumberjack) meant well but you will benefit in no way from running dull teeth. Rocks will dull them and since you know that the next stump will have rocks also you may naturally run dull ones at times. One effective way to deal with this is to change part of a set. By changing 1/3 of the teeth the machine will cut almost as well as if you had made a full cutter change but you won't have the dismay of putting the brand new set right into a rock. At least one manufacturer (Leonardi) offers more than one carbide formulation. The softer carbide is recommended for rocky conditions. Softer for rocks may sound strange but the softer carbide is less brittle and so it seldom shatters off of the tooth. It dulls slightly faster than the hard formulation but is much more durable in the rocks. Most people find it difficult to believe but, Ponderosa Pine is one of the hardest stumps to grind. They are not too bad freshly cut and can be very easy if they are several years old, but in the period from about 3 months after cutting a live tree up to about 2 years(sometimes less depending upon conditions) they are relatively difficult. Sharp teeth are needed or you will have to BEAT the stump to shreds. Gambel's Oak on the other hand is hard but grinds almost as well with somewhat dull teeth as with fresh sharp. Spruce are easy. Doug fir iis between it and the Ponderosa pine. Pinyon Pine grinds easy. You will probably never need a bigger saw than the 288. Best Wishes!


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## redprospector (Jan 28, 2005)

Stumper, since you live in Colorado I'm sure you are aware of the "vertical real estate" that people build on. I'm wondering are stump grinders like skidsteer loaders (the larger models are more stable on slopes), or would a smaller grinder be ok? I am looking at a couple with 20 hp. In your opinion would that be enough to test the waters, or am I spinning my wheels? I'd love to have one of the big ones, but I don't know if that would be the best on steeper grades. Besides, I hate to tie up 30k on a machine that I don't know how much I'd be using. I'm going to meet with a couple of customers today to discuss the possibility of stump removal, so I'll have a better idea of a response in my area.


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## Stumper (Jan 28, 2005)

If you are doing high volume work-big contracts for hundreds of stumps- then big machines are the best bet. O the other hand, if you are going to work mostly for individuals around houses etc. then the small machines are outstanding. Self propulsion will help on that vertical real estate. I have never had a concern about tipping with the Rayco and Levco machines I have used.


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## redprospector (Jan 28, 2005)

Thanks for all the good info. I'm looking at a rayco RG 20HD for starters. If that works for starting out I'll consider one of the larger grinders. I'm going to try to attach a picture of one of my jobs (118 trees from 0.8 acre). I mainly want to see if I can figure out how to attach a picture.


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## alanarbor (Jan 29, 2005)

On those steep slope areas that Track mounted Vermeer model might be a good bet.


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## Stumper (Jan 29, 2005)

Unless there are some bigger logs somewhere in there you should find that the RG20 will knock out all 118 of those stumps in a few hours. Nice looking truck and chipper from what little I could see. Is the Bobcat yours?


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## redprospector (Jan 29, 2005)

Stumper, 
There was about 3500 bd. ft. of decent saw logs on that little job. Biggest stump was about 25", average stump was about 6" to 10". I had to haul logs & firewood off every day to make room. 
Yea, the Bobcat's mine too. I retired the truck this fall (it was a 67), and built up an 89 GMC. If I add the stump grinder, I should be set up pretty good.
That's encouraging that the RG 20 could grind the small stumps that quick.
I'm sure that when I get one, and prove it will work there will be 10 more guys jump on the wagon. Thats how it worked with the chipper anyway.

Alanarbor, I like the Idea of the track mounted Vermeer. I know that tracks make a world of difference on my Bobcat.


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