PTO powered stump grinder build

[LightningCamaroGuy]

As a tool maker/die builder I can safely say that I dig it. Very cool, and nice work OP. Look forward to seeing the finished product.

 

[mrmikey]

You're going to be able to pass that machine down for generations to come. A true work of art, again I say well done.

 

[Renze]

View attachment 838671

Whats the plan with this hinge, do you want to tilt the cutter head a bit to provide controlled depth of cut, without using the tractor gears ?

 

[jwmorris]

Whats the plan with this hinge, do you want to tilt the cutter head a bit to provide controlled depth of cut, without using the tractor gears ?

No I am going to use this with our HST tractor. The idea is the hinge allows the cutter to swing away (actually hold position) if the tractor moves and the cutters can’t cut that fast, then the operator stops advancement and lets the chipping head cut until it’s back vertical.

The hinges and the clutched PTO shaft are basically “fuses”.

They are not going to move as much as in that photo above, just a few degrees will be inches at the stump, should keep the u-joints happy.

The 3/4” pin locks them so it doesn’t flop to the ground when you want to store it.

 

[Renze]

The idea is the hinge allows the cutter to swing away (actually hold position) if the tractor moves and the cutters can’t cut that fast, then the operator stops advancement and lets the chipping head cut until it’s back vertical.

I hope for you that it works the way you envision. A chainsaw has depth gauges, preventing the chisels from biting too much and stalling the engine. I dont have experience with stump cutters, but i would rather have a slip clutch in the PTO shaft as driveline protection, and have the cutter assembly as rigid as possible. Also, your link arm stabilisers would need to be very tight or it will rock left to right whenever you engage a stump.

But i am keen on following this project and see how it pans out on the test run, i have only watched stump cutters from a distance so i might be wrong off course

 

[ruffdog]

Many small grinders are designed with the forgiving swing away feature. There are several 3pt makes and skidsteer ones too. I like how the OP is adding heft to his as that should help with it hopping while cutting...good job and keep us up to date.

 

[MTGreen]

Many small grinders are designed with the forgiving swing away feature. There are several 3pt makes and skidsteer ones too. I like how the OP is adding heft to his as that should help with it hopping while cutting...good job and keep us up to date.

That one looks like a toy compared to what the OP is fabricating

 

[ruffdog]

That one looks like a toy compared to what the OP is fabricating

No kidding! Pretty wimpy compared to what we are watching being built.

 

[jwmorris]

Exact same concept though. There are a number of outifts that make them based on the same concept, not an original idea just the execution and I‘ll admit I wouldn’t build them like this, if I were selling them but I was using as much scrap as I could.

I didn’t get too fancy with setting the tooth angle, just a slight inside rake, squaring the face with the centerline.

Set the angles with some aluminum cut to the proper angle and a “shim” for depth of cut.

Then finished welding it out (photos - the 2 spots I missed).

Luckily I took so long on this project @pmsmechanic , had me go get a balancing machine from the farm and bring it home. It did catch two welds I missed though.

 

[Renze]

Many small grinders are designed with the forgiving swing away feature.

Very interesting !! I have been thinking about building it simple like that, but thought it wouldnt work. All stump grinders here in Europe are heavy duty commercial ones with outriggers for a firm stance.

And it works good on a 20hp compact too.. i have 60hp at my disposal.

I am just not sure when i build one, do i want it like this, super simple, or do i want one with an angle gearbox, which i can rotate 90 degrees so i can also use it as a tree saw, cutting at ground level without dulling my chainsaw in the dirt... it would be really cool if i could just run over things backward, for fencerow cleanup.

 

[jwmorris]

I am just not sure when i build one, do i want it like this, super simple, or do i want one with an angle gearbox, which i can rotate 90 degrees so i can also use it as a tree saw, cutting at ground level without dulling my chainsaw in the dirt... it would be really cool if i could just run over things backward, for fencerow cleanup.

I wasn’t either, the first one I built, years ago now, was another scrap build that was a side to side swinging one but manual. It works but is a lot of work or I am too old.

I built it when I was given this cutting head.

Used an old brigs 8hp engine that I threw and electric starter on, the go kart brake on the axle is so you can throw a lever on the tiller handle bars, locking that wheel, making it easy to swing the arch.

Battery up front for weight over the cutting head.

I will say this, that one takes up more floor space in a barn than this one will, if that’s important.

I wouldn’t be too worried about dirt but our place has lots of rocks and gravel. So I threw This trailer together so I can blow them away from the stumps, so I can get them below grade.

It’s work too but I imagine the teeth last much longer just hitting wood.

I’d trade for one of these though.

 

[5030]

I wasn’t either, the first one I built, years ago now, was another scrap build that was a side to side swinging one but manual. It works but is a lot of work or I am too old.

I built it when I was given this cutting head.

View attachment 839015

Used an old brigs 8hp engine that I threw and electric starter on, the go kart brake on the axle is so you can throw a lever on the tiller handle bars, locking that wheel, making it easy to swing the arch.

View attachment 839016

Battery up front for weight over the cutting head.

View attachment 839017


I will say this, that one takes up more floor space in a barn than this one will, if that’s important.

I wouldn’t be too worried about dirt but our place has lots of rocks and gravel. So I threw This trailer together so I can blow them away from the stumps, so I can get them below grade.

View attachment 839032View attachment 839019


View attachment 839025

It’s work too but I imagine the teeth last much longer just hitting wood.

I’d trade for one of these though.

View attachment 839018

In reality, quality tungsten carbide teeth will deal with rocks pretty well.

 

[jwmorris]

One of the drawbacks of not drawing out plans is you have to measure things at the end and machine to fit.

I started out running PVC through all of the components and measured from there.

Then machined the shaft for the hub.

Froze it so it pressed on a bit easier.

The weld photo must be on my phone but I used the same rotary table and then faced the hub off to ensure it’s perfectly square. It was fine but it looks nice faced...

Then put it together again to measure for the rear bearing.

One more trip back to the lathe and...it’s time for a drink.

 

[jwmorris]

I torqued everything down, bolted on the PTO shaft, loaded it and a box blade I had to repair. Ready for a test run, once I run in the clutch. I hope, would have been nice to have had a tractor here... Keep your fingers crossed.

Hmm, seems like I am a little behind on painting projects...

 

[Renze]

I torqued everything down,

What is your background, if i may ask ? Auto or aircraft environment?
I dont know many people who actually torque stuff, most just hit it with the impact gun while mumbling "thats not goin' anywhere"

I cant wait to see a video of your test run !

 

[scott_vt]

Good Morning jwmorris,
Beautiful craftsmanship ! Being in the metal trades all my life I can certainly admire your workmanship, and your welding !

In reality, quality tungsten carbide teeth will deal with rocks pretty well.

I see the carbide cutters that your using, and believe that the large radius on the corners will prolong cutter life and hopefully prevent the carbide from fracturing !
I am curious as to price on the cutters, knowing that carbide is not cheap !Looking forward to your test run !

 

[jwmorris]

What is your background, if i may ask ? Auto or aircraft environment?

I spent most of my career building open wheel racecars.

I am curious as to price on the cutters, knowing that carbide is not cheap !

They were $11/ea, not a deal breaker but it adds up.

 

[jwmorris]

It was dark by the time I put out hay and attached it to the tractor but I had to try it out anyway.

This was #1, before.

And after.

And less than ideal weather this morning so a decent video will be after Christmas. For now this is all I have.

This is how the fire pit turned out, radiates a lot of heat.

 

[jwmorris]

Looks like this one is going to be a winner. Used it for 3 days on shy of 250 stumps (mostly smaller cedar trees) but did hit a few big oak and elm stumps.

This over 2' one was the largest.

and 8" below grade.

The teeth held up well, so far.

in action.

 

[mrmikey]

Congratulations on a fantastic build, that rigs not even breaking out a sweat .
So....you ever planning to come up to Nova Scotia for some torture testing? I've got a few stumps I could let you try it out on .