stump grinder / root saw ideas?

[Groo]

I have access to some 1/2" AR400 and the means to cut it.
I am thinking of building up a stump grinder. My initial thought was an 18" - 24" large toothed saw blade out of the AR spun with a horizontal shaft engine via a centrifugal clutch and a V belt.

Anyone try something like this?

Any ideas on what I should be looking at for HP and blade speed?

 

[jimgerken]

I made a smaller scale deal about ten years ago. It lasted a few years. Eventually is shook itself to pieces. Mine used an 8 hp engine because that is what I had. It was kindof a toy, but I learned a lot building and using it. The cutting wheel was 12 inch diameter, with 8 teeth, modeled after chainsaw teeth, but really huge scale, like to make a 2.5" wide kerf. There were right hand and left hand teeth. Teeth were made of hot rolled steel and dulled so fast it was crazy. When sharp it worked well. When dull it made noise and dust. I used the centrifugal clutch and double chain reduction drive. 3600 at the engine (max), and geared down about 20:1 total. Used 40 and 50 chain. One inch shafts and bearings all held up well.
You can benchmark commercial units to get an idea of the sizes, HP, gear range, etc. I would suggest you research carbide teeth, replacement parts from a commercially available trencher/stump grinder, like a woods, or whatever brand. Buy the teeth, and design around them. Without the right teeth, the thing is dull in a matter of hours, then it sucks horsepower for no progress. The proper teeth kinda smash their way thru the roots, not really a clean cutting like a chainsaw tooth.

 

[J_J]

Go ahead and cut the rotor out of the AR400, but drill holes for commercial stump grinding replaceable teeth.

 

[Groo]

Go ahead and cut the rotor out of the AR400, but drill holes for commercial stump grinding replaceable teeth.

Not a bad idea. The only problem I see is we'd be talking the difference between 1/2" kerf vs. 3" or 4" kerf. If by some miracle, I got the gearing right the first time it would be quite a bit off afterward.
Its probably worth getting the specs of a commercially available tooth though. If nothing else, AR will hold a key-way better than would a36.

 

[swick1]

Ar is a b**** to grind. I'd use mild steel and weld in a keyed bushing or do a hub and bolt system like on a truck wheel.

 

[Groo]

Ar is a b**** to grind. I'd use mild steel and weld in a keyed bushing or do a hub and bolt system like on a truck wheel.

???? so is carbide. the harder it is, the longer it lasts.

I am thinking more and more to just start with commercially available replacement teeth. I'll probably still to AR. If for no other reason than I could make a go of it if I have a problem with the commercial teeth.

 

[Piston]

I would try to copy an already available stumpgrinder design. They've already put a lot of time and money into research and development and you know they work wonders. I often thought about trying to convert my stumpgrinder to be able to turn 90 degrees, and use it as a tree saw. However, I'm not going to try it.

 

[sparc]

Maybe build something that could use replaceable teeth like this.

Green Manufacturing - The Greenwheel

 

[woodlandfarms]

Whe would you find these plans?

I would try to copy an already available stumpgrinder design. They've already put a lot of time and money into research and development and you know they work wonders. I often thought about trying to convert my stumpgrinder to be able to turn 90 degrees, and use it as a tree saw. However, I'm not going to try it.

 

[sparc]

I would try to copy an already available stumpgrinder design. They've already put a lot of time and money into research and development and you know they work wonders. I often thought about trying to convert my stumpgrinder to be able to turn 90 degrees, and use it as a tree saw. However, I'm not going to try it.

That's how they do it in china isn't it....copy someone elses' design.
I guess the difference would be he would be making one for himself and not selling them.

 

[Piston]

Whe would you find these plans?

I'm sure you can't find the actual blueprinted plans on exactly how they are put together, but studying the parts breakdown from the manual could give you a really good idea of how it works, and what the components are made of.

I have a Shaver SC50 stumpgrinder, and I just downloaded the manual and parts breakdown from their website.

 

[Agent Blue]

That's how they do it in china isn't it....copy someone elses' design.
I guess the difference would be he would be making one for himself and not selling them.

I don't think by building a " look alike " design your infringing on any patients. If that is the case quick buy a trailer because your morals won't ever let you attach an axle to some square tubing and hitch it behind a vehicle. Engineering goes a triffle deeper than a non measureable image. Besides its not for production as a business. New ideas are not always new. Parts and pieces of someones dream came from many visual experiences called life. Does it come as a surprise we have copied foreign based ideas ?
People that talk.... are talkers. People that take ideas, steel, wood, and other structure are " creators ". Long live the individual with talent and fortitude.

 

[jwmorris]

You can violate patents as an individual but there is not much incentive for a company to take you to court. On the other hand "look alike" doesn't mean you have copied the features that have been patented.

 

[jwmorris]

To the OP's question, how are you going to cut the AR plate. Having use AR 500 for rifle targets for years, I can tell you that the edges get softer when you cut them. Yes, even with a water bath plasma.

 

[Groo]

I would have used a 3kw laser, but I'm not at that job any more so the plans are off.

 

[jwmorris]

Laser does the same thing just a smaller heat effected zone than plasma or oxy/act, doesn't matter how small it is if that is the edge you are working. Water jet might work but I haven't tried it yet.

I would prefer something removeable like bolt on inserts but would likely solder carbide inserts onto the steel "saw" before I used just the steel by itself.