LOL! Mower hydraulics not connected in this PT demo!

[SpringHollow]

Hi Carl,

It is direct drive. Direct drive is simple, belt drive would absorb some of the shock but would likely slip easier. The biggest negative is that your machine can take a beating if you cut too deep but the hydraulic motor usually stalls if you do. I reversed the blade to throw away from me.

Ken

 

[woodlandfarms]

I guess the quest would be to find a motor with strong lateral loading that will spin at 800 rpm. JJ, any thoughts?

 

[BobRip]

An early PT video showed the stump grinder cutting through a stump with ease. I have stumps that go like that and they are rotten. At least these showed a real stump The small stumps, say under 6 inches go very quickly. The bigger ones (over 18 inches) can take hours, but it is still faster than any other way that I have.

 

[Gravy]

I broke the mounting ears on my my stump grinder motor (by abusing it as a trencher and hitting too many rocks). If I were starting from scratch, I would probably use a cogged belt drive to cushion the shock and allow maximum cutting depth. I would also design for lower RPM's and higher torque.

As it is, I have a spare motor that will work with a little modification.

 

[SpringHollow]

I have done stumps over 24" and none of them even took 30 minutes. I did 20 or more stumps at a friend's house in about 1/2 a day but some of those were only 8 or so inches (wider at the base but that wider part breaks off pretty easy). But my tractor is just slightly larger than yours and i was pretty hard on it.

Ken

 

[J_J]

I guess the quest would be to find a motor with strong lateral loading that will spin at 800 rpm. JJ, any thoughts?

If you need a hyd motor that will turn around 800 rpm, the displacement will be 5.77 cu in. and at 3000 psi, the torque will be 2756 in lbs.

Different scenario.

Surplus Center - 24.7 cu in PARKER TG0405MS030AAAB HYD MOTOR

This motor has good torque, but only turns at 162 rpm. Working pressure up around 3000 psi.

Anybody know the rpm of their stump grinder?


20 GPM at 3000 takes about 41 HP to run the pump. A hyd motor at 85% efficiency would develop about 34 HP

 

[woodlandfarms]

I have seen other hydraulic stump grinders running at 800. That is where I got my idea from. I found a motor at surplus that sounded good but I can't figure for the life of me how to cut and paste on my ipad

 

[BobRip]

I have seen other hydraulic stump grinders running at 800. That is where I got my idea from. I found a motor at surplus that sounded good but I can't figure for the life of me how to cut and paste on my ipad

Double tap on the area. Then drag the dots to the area you need. Then select cut. Go to where you want and then double tap and select paste. Instead of double tap you can hold your finger down for a few seconds.

 

[woodlandfarms]

BobR. The fact you have an Ipad I find wonderful.

Thanks for the advice. I am a huge mac addict and the wife got me one for my birthday, but I am pulling 16's at work and have not had the time to do much more than email....

 

[woodlandfarms]

So, I thank Bob R for the tip

Surplus Center - 4.95 cu in DYNAMIC BMS80E2GS HYD MOTOR

So what do you guys think for a direct drive stump grinder? if this is good I think I can build one with teeth and all for under 1500.

But I have never heard of DYNAMIC as a brand. White, Charlyn... Afraid this is some chinese off brand and will just shrapnel under the load.