Hello Jared,

Nice video, I haven´t used a ground driven (horizontal) rotary harrow. But I have seen them laying around and in books.

The ground driven rotary harrow is like you mentioned an old principle. Such a harrow has one or two circle shaped harrows.

A horse drawn single circle harrow can have a weight on top, which is positioned perpendicular on the pulling/moving direction and placed one side of the spinning axle. And can be positioned over this length in- and outward. This makes that the teeth go deeper in the soil (on that side). This creates more friction on one side of the harrow and makes the harrow turn. The more this weight is placed towards the centre, the more faster the harrow spins.
First the proper line of draft (angle) is set and then weight is set. Which position depends on soiltype, moisture and hardiness of the top layer.
Added is a picture of such a single circle harrow, I have no close-up pictures…

I would not think from the theoratical point of view, that this creates side draft. When used on a hard surface the harrow will move sidewards. Because the harrow can´t digg in.
Some models have curved teeth to better digg in, though “common” are the straight teeth.

The harrows with double circles are mounted on an vertical axle that tilts (set on an angle) to work the same as the single circle. (see picture)
I’ve seen one version of the double circles that uses the circles as wheels in the transport mode. And in the field is changed to working position. Shown in the other picture.

The three point hitch models are set to “digging” with the top link. This is in line with the of moving direction.

This way of harrowing also has the effect of less crop residue clogging up.

Another tractor version is shown in the video, as said to believe it works good in the barrel racing and rodeo arena aswell.



You must be logged in to view attached files.