Stump grinder build

[Yooper]

The graphite bronze idea I like. I think I remember seeing ones in the Bible (McMaster) that had 'dots' of graphite in them. My reasoning for plastic was because of dirt being an issue at this joint. I'll check out the graphite. Thanks!

 

[bmblank]

McMaster is the bomb. Where I work we do low enough volumes that we pricy get all our hardware from McMaster. It's so nice to be able to just download solid models. The little bit of extra cost is totally worth what you get from them.

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[Yooper]

I think I've actually seen graphite impregnated as well. That may be a better choice to prevent buildup. Sand/dirt/dust/debris tends to attach itself to oily things. Not sure if the bronze bushings are oily enough for that.

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I second this. If not using actual bearings, then I tend to use oil-impregnated bronze bushings or washers where they are under load. I typically purchase from McMaster-Carr (mcmaster.com). Cannot beat the selection and technical detail, though pricier than most (though not typically an issue foe a few bushings or similar). Great to see the continuing progress.

I've got some Oilite bronze but I don't think this would be the right application. Thinking it would be be a magnet for dirt/ abrasives.

 

[Tooljunkie]

It would be in your best interest to make your wear parts easily replaceable. One set of spares, if at all possible the wear parts being made similar throughout so only a couple sets of spares are necessary. Well placed shields will keep most of the abrasives down around cutting head.making great progress.

 

[Yooper]

It would be in your best interest to make your wear parts easily replaceable. One set of spares, if at all possible the wear parts being made similar throughout so only a couple sets of spares are necessary. Well placed shields will keep most of the abrasives down around cutting head.making great progress.

Good point. Since I've never operated a stump grinder, I'm not sure where the critical points are. I know from watching videos that it's going to throw dirt and rocks and I'm keeping that in mind as I go.

Maybe I'm overthinking this, but the swing portion is working constantly and I want a way to keep it tight. I don't want this thing doing the 'hop'.

 

[Yooper]

Working on the yoke here. Didn't have any 1-1/2 thick wall tube left, so I had to use solid bar which means drilling and boring the hole for the pin. Then I started fly cutting the surfaces for where it will attach to the 3 point hitch.

 

[Yooper]

Finished fly cutting the surface and then rinse and repeat for the other side. This will give me parallel surfaces for mounting to the 3 point hitch. I'm at the point where I have to bring the tractor into the shop and start finalizing the hitch design. Also have to remember to put a grease zerk in the tube.

 

[Yooper]

Does anyone know if there is a source for CAD drawings for my L3901?

 

[Yooper]

Welded up the adapter head and tacked it on the end of the boom for a test fit. Mounted the right angle drive and motor on plus the cutting wheel. I knew the clearance was somewhat tight and was happy that the coast is clear. Finished welding the adapter to the boom.

 

[coachgeo]

Good point. Since I've never operated a stump grinder, I'm not sure where the critical points are. I know from watching videos that it's going to throw dirt and rocks and I'm keeping that in mind as I go.

Maybe I'm overthinking this, but the swing portion is working constantly and I want a way to keep it tight. I don't want this thing doing the 'hop'.

Something you mentioned while back (underlined above) has been bothering me for a while about this project.

IMHO... go rent one. Clean up a few neighbors stumps for them. There is NOTHING LIKE first-hand experience to understand the reasoning behind how/why something is built. The forces and resulting action can only be scientifically speculated and then engineered/built around so much.

 

[Yooper]

Won't argue with your reasoning. Can a stump grinder for a tractor be rented?

But beyond that, I have a history of building things first before I ever operated them. For example, the first sheet metal brake I operated was one that I built, capable of 73" x 1/8" steel. Hydraulic. Took about two months to build and enjoyed every minute of it. Friend still uses it today in his shop. (Built it 27 years ago)

As far as the neighbors stumps go, they're going to have to wait. I have between 300-400 stumps to grind on my property, which I hope to be doing this fall.

 

[Vraz]

Won't argue with your reasoning. Can a stump grinder for a tractor be rented?

I have seen few 3PT implements available for rent. However, if the goal is to observe the interaction of the stump grinder head vs your stumps, not sure 3PT is important. Just rent a self propelled and evaluate how hard/easy to manipualte, how its built, how much gunk gets caught in the drive train, etc.

But beyond that, I have a history of building things first before I ever operated them.

Creates a different learning curve, but my experience is similar. In most cases, no good reference was available so was not really a question of choice. If you have state/county fairs around you, that is another way to get close to such implements (or at least here in MN it is). Keep those updates coming-- good stuff!

 

[Yooper]

Time to weld everything up and make a unit out of it. Also welded up the guard. The outside plate for it will bolt on the weld tabs set into the outer ring. I know this much, I won't be lifting this guy by hand anymore! Getting heavy.

I have to get the structure for the 3PH finalized before I can weld the attachment points for the vertical and horizontal cylinders.

 

[North Idaho Wolfman]

I was under the impression that this was either going to be loader or front mounted, three point will work too, if you were doing three point why not PTO powered?
Side to side motion would make PTO shaft tricky.

One note:
I don't know if it's going to matter or if you've already considered the three point has no down pressure it will simply float, and that might be exactly what you are looking to do.

 

[pacer]

Absolutely great post yooper! Keep em coming!

In case some of you havent seen one of - the many - 3pt hitch stump grinders heres a couple pics of one I recently adapted to my little BX25. Its from Iowa Farm equip, a SG26, which means its got a 26" cutting wheel. It weighs a whopping 680lbs so that may be why yours is getting a bit heavy yooper. It strains the little BX somewhat, but the saying for the BX's "it'll do anything a big tractor will do - it'll just take a bit longer" applies here.

 

[Yooper]

I was under the impression that this was either going to be loader or front mounted, three point will work too, if you were doing three point why not PTO powered?
Side to side motion would make PTO shaft tricky.

One note:
I don't know if it's going to matter or if you've already considered the three point has no down pressure it will simply float, and that might be exactly what you are looking to do.

I seriously considered PTO driven but the extending boom is what threw me. I just feel more comfortable working with hydraulic hose vs a driveshaft that would have to be able to extend while turning plus angling left to right.

Honestly, I don't have a lot of experience with 3PH. Thanks for pointing out the floating thing. The bottom of the 3PH structure will have 'teeth' that will anchor into the ground when lowered. Just taking a cue from almost all the 3PH grinders I have studied.

 

[Yooper]

Absolutely great post yooper! Keep em coming!

In case some of you havent seen one of - the many - 3pt hitch stump grinders heres a couple pics of one I recently adapted to my little BX25. Its from Iowa Farm equip, a SG26, which means its got a 26" cutting wheel. It weighs a whopping 680lbs so that may be why yours is getting a bit heavy yooper. It strains the little BX somewhat, but the saying for the BX's "it'll do anything a big tractor will do - it'll just take a bit longer" applies here.

Thanks for posting the pictures, Pacer! I've got a couple of questions. Is the square tube going vertical by the grinder for 'parking' it? I want to do something on that order.
I see your grinder flings the chips away from the tractor. A guy I talked to that built his own made the remark if he did it over again, he would have it fling the chips toward the tractor (with a shield of coarse). He said it would operate smoother. I see the commercial ones mostly work this way, so I'm aiming this way. How smooth does yours run?

 

[skeets]

DAYUMMMM you do nice work !!!

 

[pacer]

yooper,

"Is the square tube going vertical by the grinder for 'parking' it?"

Yes, that is its "parking brake" Obviously you wouldnt want to set the wheel down and risk damaging one of those pricey carbide teeth!

"How smooth does yours run?"

With my small tractor - and small engine - it will bog down without keeping my eyes/ears tuned to its sounds/feel very closely. When it gets too crowded it will not only bring the RPM's down but will go to "hopping" I have a feeling that with a higher HP engine this would be much less of a problem...

I think that the heavy weight and mass of the frame is a critical element in keeping the 'hopping' toned down and maintaining smooth movement across the stump. From what I'm seeing on your build youre building that "mass" into yours.

 

[bmblank]

I would think the turn of the wheel would help with chatter also. Seems too me that kicking the chips toward the tractor would help "pull" the grinder into the stump.

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