Stump grinder question

[davesisk]

Considering that the stump grinder pelts the operator with wood chips, dirt, and rocks, I'm thinking about how to turn it around so that it spins the other direction (and throws stuff away from the tractor).

Easiest way: 1) Switch the hoses, and 2) take the blade off and turn it around. Question is: will this high RPM hydraulic motor turn in reverse if I switch the hoses?

If you haven't seen one up close, here's a link to the pic:

http://www.ipass.net/~davesisk/tractor.htm

Give it a look and tell me what you think...

Dave

 

[Charlie_Iliff]

Dave:
I understand the slow-speed motors, such as on the auger, will crank backward, but PT and other manufacturers are reluctant to put a reverse valve on the machines for fear of damaging other implements. I have assumed that to mean the high-speed motors. You may want to call the motor manufacturer.
I can't tell enough from your photo about how dificult it would be, but would suggest your fabricating the brackets to mount the whole works the other way around.
I have to assume PT had some rason for mounting it that way in the first place. Have you talked to them about it?
I don't have the stump grinder, but found I could dramatically reduce the shower of dirt and rocks from the tiller just by tilting it back. Is there a guard plate on the back similar to the top one in the picture that you can position with the curl control?
Hans (Bubenberg) has a grinder and perhaps can make some suggestions.

 

[davesisk]

Hmmm...that's a thought. (I was wondering why the hydraulic PTO didn't have a reverse on it...seems like that might be useful for a power auger, etc.) There's a guard above the grinder, but nothing below it. If you tilt it down far enough to see what you're hitting with it, then that's also far enough to get beaned with a rock. I thought about maybe making a plexiglass shield, but somehow I don't think it would last very long.

Now, the whole assembly bolts to the plate with 3 bolts, so I could easily turn the whole thing over. The only problem is that the metal shield that was on the top would now be on the bottom...

I did mention this to Don at PT once. He said that if you turn it around, it will push the tractor. I think I could personally deal with that better than being pelted with rocks!

Dave

 

[MossRoad]

I would think that, in the current setup, if the blade stuck on something, it would force the front of the tractor to bounce up and off of the obstruction.

If you reversed the spin of the blade, and it stuck on something, it might want to pull the front end of the tractor down and dig into the obstruction further. Theoretically, if the hydraulics were strong enough, if would lift the rear end of the tractor off of the ground and fling the operator forward out of the seat and onto the stump grinder, possibly INJURING said operator. (YUCK!)

Also, I wonder how high and far it could throw debris if you had it spinning the other way?

I'd be inclined to build a better chip guard out of lexan or very heavy expanded steel.

Edited after poor chioce of graphic injury description /w3tcompact/icons/blush.gif

 

[Charlie_Iliff]

Dave:
MossRoad's suggestion is altogether too graphic. it makes sense, however that you'd rather have the machine pulled up and forward rather than down and back.
Regarding the chip stream, does the machine currently throw chips forward with the top of the wheel, as well? It seems to me likely that some will be thrown at you even if the rotation is the other way, as chips ride part way around. I have to agree with MossRoad: a chunk of lexan or expanded metal may be the best bet - - or, you can ship the stump grinder up here, and I'll be happy to test it thoroughly on 8 or 10 stumps that don't quite justify buying my own grinder. /w3tcompact/icons/smile.gif

 

[davesisk]

Alright, good points here. I think you guys may have talked me out of attempting this. Forward/Up is certainly more desirable than Backward/Down. Very good point.

Dave

 

[Charlie_Iliff]

<font color=red>MossRoad's suggestion is altogether too graphic.</font color=red>
MossRoad:
I wasn't suggesting that you edit the post. I meant that your identification of the possibility was a good reason not to turn the grinder around. When it comes to damage to humans, I suspect stump grinders can easily compete with chain saws for gore, they just are a little further from the operator. Your original post made the point quite well that reduction of the distance between the operator and the grinder might tend to ruin the project.
I wish I could justify a PT grinder, but for the little I need done, I'm probably going to have to rent a walk-behind grinder.

 

[davesisk]

Charlie, if you were geographically close, I'd loan you mine for a weekend. Of course, you'd have to figure how to deal with the 3-pin attach vs quick attach...

Dave

 

[MossRoad]

I know /w3tcompact/icons/smile.gif.

But it was pretty gory, so I decided to change it. I think we all got the point.

 

[MossRoad]

Bump for reference