Stump Grinder

[jrlichina]

You have to make sure the motor is bi-directional. If it doesn't have relief/check valves on both ports you can't run it both directions. If you do you will blow out the seals. If it is bi-directional all you need to do is plumb a motor control valve into the source so you can change the motor's direction of rotation.

 

[Taylortractornut]

a backhoe is built to crowd towards the machine, If you change the rotatin itwill want to cause alot of wear and the hydraulic ram as its working against the masller side of the cylinder. It also would put alot of stran on the crowd clylinders pivot its closer to the edge of the plate its on because in normal operation it never puts much stress on that side of the joint. If youll lokk at most stump grinders they throw the material back to the machine like yours does but they have a plexiglass sheild. I used to run one on a Bobcat that was set up like that and our safety man had us hook them up backwards to blow the chops our. It shook the hole machine and made it harder to stay on the stump. The other Bobcat we had vibrated enough to crack the pivots on the loader arms. We changed them around back to original rotation and used the plexiglass. It worked alot better.

 

[Brad_Blazer]

Nice work on the grinder!
If you reverse the rotation it's making a climb cut. The blade rotation pulls the blade into the cut making the whole thing inherently unstable. Avoiding climb cuts is a fundamental safety practice for using almost any rotating tool. The pivot point of the tool support must always be placed so that the blade rotation will move the tool away from the cut if it "catches" on something.
Brad

 

[have_blue]

Hi John,

What a beauty! I could really use that down here in Cajun country where dynamite is not an option. Looks like you got your revenge on that apple tree stump!

Just wondering John. Do you have any problem with "chatter", or oscillation of the BH boom and linkage? I can imagine the cutter being hard to keep engaged with the stump because of chatter and squirming because of the long boom.

 

[JohninCT]

Thanks Have Blue

Yes there is some chattering, but not as much as I thought there might be. The "squirming" off the desired cut area is more of the problem. If you notice how these stump grinders work they use the side of the blade. With my configuration it is not easy to accurately control the side to side cutting action. What I am thinking of doing is mounting the cutter head at an angle so that I can use the bucket curl to bring the side/edge of the blade into the stump making at sort of "scooping cut". The other adventage of this setup will be to throw the chips more out to the side rather than directly back at the machine. I haven't gotten around yet to doing the cutting and welding on the bracket to make this change.. too many other things to do. May be one of my winter projects.

John