bush hog windrowing

[Rowski]

Glenn

Would ground speed have anything to do with it? It would seem that slower ground speed would result in less windrowing, maybe? Also could the "tip" (front higher, lower or level with rear) of the cutter have something to do with it? Maybe the right combination of them all could fix or reduce the windrow problem.

Derek

 

[glennmac]

There obviously can be a number of variables that affect material discharge. Another I thought of is the back of the cutter. Some have a solid shield, which would tend to keep material and air under the cutter. Some have chains, which would seem to be able to hold material but let swirling air escape easier. Finally, some people run with no shield or chains at all, just the large opening, which will discharge more material. I dont know how any of this would affect windrowing.

 

[MDNick]

At least theoretically, ALL brush hogs should rotate CCW. And it ain't got a thing to do with the brush hog. ALL PTO's rotate clockwise (save for that one Kubota, B6100???), when viewed from the back. And pretty much all brush hog gearboxes are nothing more than 2 bevel gears. So you get a direction change there, the brush hog will always turn CCW when viewed from the top. Unless the manufacturer opted to use a more complex gearbox, and there is no good reason to.

Farmer kid usetabe, Farmer Wannabe

 

[Rowski]

<font color=blue>As for the finish mower, yep, the blades on every one I've ever used turn clockwise; just the opposite from the brush hog (and I have no idea why). Even my rear discharge finish mower has the blades turning clockwise as viewed from the top.</font color=blue>

Bird this has been driving me crazy. I don't even own either of them. I found some parts diagrams of a rotary cutter and finisher mower gear boxes. The only difference in how the different direction is accomplished is by placement of the input bevel gear. After comparing the two diagrams and seeing the placement of the bevel gear I was still unsure. Now, no laughing.... I VISUALLY proved my point to myself by using axles and bevel gears on my Legos. Pretty sad a 29 year old is still playing legos. Attachment show it far better than I could ever explain.



Derek

 

[glennmac]

Derek, do your legos windrow in the left or right?

 

[TomP]

OK, here goes my two cents. The shape of the blade where the edge is, provides an airfoil, lifting the cuttings up into the chamber to be recut, by drawing air from outside the cutter inward(ie- a vacuum), yada yada yada. As the mower moves forward, the areas experiencing the greatest wind-swept area will be on the right and left sides. Additionally, the blade speed is highest at the circumference of the blade cutting circle. That should add to airflow, and keep cuttings suspended best on the outer edge of the blade, providing all other things are equal.

If you raise one edge(front, back, or either side), you reduce the vacuum, and cuttings drop there, or a little after that point of rotation. I think that's why the rear is supposed to be a little higher than the front. Using the same argument, if your left side is higher, you'll drop on the left.

Theoretically, since the center of the cutter has the least amount of vacuum(no edge, no blade, and no windspeed), the cuttings should dop on the center line(and out the back if it's raised).

One thought--on a CCW rotation, the right side isn't cut as well since your wheels just crushed the grass ahead of the mower. This ought to decrease the vacuum efficiency on that side--the grass isn't standing as tall as that immediately surrounding it. SO,.....maybe we should really have the right side lower by 1/2" to offset that.

What do you think? If you practice in front of a mirror, and can preach this with confidence, you might start to believe it. Seriously though, try it out and see if you can make the windrows shift or go away by changing the level front/back and left/right, and post your findings. After all, I'm just a pizza guy.

 

[Rowski]

Depends on how I dump the BIG box that they are in. But usually no. They need to be spread out evenly, to allow one to see and find the peices that one needs.

/w3tcompact/icons/smile.gif/w3tcompact/icons/smile.gif/w3tcompact/icons/smile.gif





Derek

 

[Bird]

Derek, I haven't gotten into that deep thinking yet on this topic./w3tcompact/icons/laugh.gif I don't know whether the gear boxes are different or not, but perhaps one consideration is the fact that you only have one spindle to turn with the brush hog; i.e., direct drive from the gearbox, while the finish mower has the direct drive out the bottom of the gearbox, then a belt to turn multiple spindles (blades). I've never thought about whether the belts reverse the direction or not. I guess it wouldn't be very difficult to remove the belt cover and see which way the output shaft turns on the finish mower (if I cared enough to do it/w3tcompact/icons/laugh.gif).

Bird

 

[theboman]

Upon a closer look I do stand corrected (a first time for everything...I'm single), my rotary cutter windrows to the left like everbody elses. I ain't too smart, just really good looking.

Speed causing the windrows? Nope. It's the sides of the rotary cutter. The grass/weeds etc builds up on the side and trails out the back of the cutter. It ain't no other way out.

Bluegrass, Pick It Up!