PT 425 PTO Specs

[Gravy]

JJ,

Mine has a 1" straight shaft with a keyway. I think it's about 3 cu.in./rev. I think I calculated the speed at about 660rpm.

 

[mlhunter]

I converted my stump grinder to a 2" square mount so I could use it horizontally. That lets me approach the stumps from different angles. I've cut down a few saplings, but it was painfully slow. If I were going to use it for brush clearing, I would definitely adapt a circular saw blade.

I also think a heavy duty circular saw blade might be best although I wonder how much flexing the blade might do as the tractor is moving side to side or forward to backward unevenly. If possible I would want to bolt the blade directly to the stump grinder's tooth mounting plate rather than adapt it somehow to the hydraulic motor shaft. The tooth mounting plate diameter is 14". To cut a 4" tree we would need a 22" or larger blade.

I spent the better part of today chasing down large blades on Craigslist and Ebay. I found several possibilities, usually older ones from primitive "buzz saws". One seller noted the blade was rated for 2200rpm. The teeth were aggressive and that is noticeably slower than most saw blades which would be in my favor. However I don't know how difficult it would be to drill holes in a saw blade accurately enough to keep everything balanced and true.

I also tried to locate a heavy duty pillow block, mandrel, arbor setup heavy enough to belt drive a large blade and I could not find anything worth working with.

What I did find is some useful info from this web site. Turbo Saw - Tree and Brush Cutter for Skid Steer. This blade turns at 2000rpm at 10 gpm minimum. The shape of the blades could be duplicated on a smaller scale and bolted to the stump grinding teeth mounting plate. My brother suggested trying high speed rotary hay mower blades on it. If they were 1/4" thickness they might be heavy enough.

They also have a tractor model at Turbo Saw - Tree and Brush Cutters for Tractors.
To quote them "This model runs a high speed circular disc with durable carbide cutting teeth, the Turbo Saw TR3200 can operate on tractors with 28 - 120hp. On a 540 rpm PTO the disc turns at 1000 rpm cutting up to 8" per second. The mining grade carbide teeth can contact the ground to insure a smooth ground level stump."

I would be happy to be cutting at 4" per second! Actually I'd be quite happy cutting 1" per second! It looks to me like this may be doable!

I'm going to mentally process this a bit more but right now I think this is the direction I want to go. My brother has access to a plasma cutter to cut out the blades and I have a heavy duty drill press for precise drilling of the holes. When finished we can harden the blades by heating and water quenching.

Any and all thoughts on this would be deeply appreciated!

 

[J_J]

Have you considered a hyd chainsaw?

Have you also considered a 1/4 in thick bld and then braze on carbide teeth. My stump grinder teeth are brazed on.

 

[MossRoad]

Have you thought about just taking the PT stump grinder and rotating it 90 degrees? It might not be fast, but it will probably do the job, AND you can turn it back 90 degrees and still grind stumps, if needed. Two implements for the price of one.

 

[mlhunter]

Have you considered a hyd chainsaw?

Have you also considered a 1/4 in thick bld and then braze on carbide teeth. My stump grinder teeth are brazed on.

We did consider a hyd chainsaw but ruled that out for a couple of reasons. Having used my chain saw on this kind of work, I've found that its tough on chainsaw blades, hit one rock or too much dirt and its done cutting. We also think because of the rough nature of that kind of work using a tractor it would be awfully easy to bend the bar, lose chains, etc.

I like the idea of building our own blade and brazing (or welding) on teeth! We have access to a plasma cutter so we could cut out our own blade. We could drill holes in the new blade with a drill press. I also think the 1/4" thickness would be ideal for the available power. It could also be bolted on to the stump grinder blade.

I really appreciate this idea! We expect to use this idea as a basis for what we build!

 

[mlhunter]

Have you thought about just taking the PT stump grinder and rotating it 90 degrees? It might not be fast, but it will probably do the job, AND you can turn it back 90 degrees and still grind stumps, if needed. Two implements for the price of one.

That's basically the underlying idea I've been working with as we occasionally need the stump grinder also. We think this might work for the cedars as their trunks are pretty stiff and also soft. We have doubts that it will work for the smaller stuff that tends to whip around.

We'll definitely try it before we go any further with the project!

The cool thing about JJ's idea is that once set up properly different blades could be made for different purposes. I was about to give up on this project but with his idea as a basis I think we can 'git er done'.

This project is going to take awhile! I'll post a picture of it when we're done and maybe my son can video it at work!

 

[mlhunter]

Thanks to everyone that contributed ideas to this project! They all helped to gel thinking on this project.

Now comes the easier part, gathering the parts together to "git er done"!

 

[SpringHollow]

There are also bolt on carbide teeth.

Ken

 

[Gravy]

Have you thought about just taking the PT stump grinder and rotating it 90 degrees? It might not be fast, but it will probably do the job, AND you can turn it back 90 degrees and still grind stumps, if needed. Two implements for the price of one.

I've tried that, but it's not very good at brush cutting. The teeth on my stump grinder are around 1/2"-3/4" wide, and pretty blunt. They will eventually bludgeon a sapling to death. The kerf width is around 1-1/2" or so. I'd think that sharp teeth and a kerf in the 1/8"-1/4" range would work a lot faster.

If it were my project, I'd try to find a cheap old rip saw blade and adapt it to the stump grinder motor. Failing that, I'd get a steel plate disc of the appropriate diameter and thickness and hack some kind of teeth into it. It could be really ugly and still work well enough. It doesn't have to be really precise or well balanced. It just has to cut through brush and saplings.

 

[ernemats]

Check out the Gravely saw blades on e-bay. They would probably be to large for your idea.