GRADE-MAX Graders: How They Work • TWIN BLADES-PITCH-ANGLE-SIDE PANS
These pull type graders will give you better results than a motor grader with the ease, durability and efficiency of a box blade at a fraction of the cost when compared to a motor grader.
Motor graders, box blades and other grading implements only have one cutting edge. Our Grade-Max graders have two cutting edges which allows you to cut twice in a single pass and this is only a small benefit of a twin blade design when it comes to pull behind graders. You have two cutting edges constantly cutting, mixing and relaying your road surface. A similar technique is used when relaying asphalt roads. They cut the top layer off and then relay the road surface.
The Grade Max Grader has two cutting edges which are fixed on a precise pitch which our family has perfected.
When pulled forward into the road surface, this pitch utilizes the weight of the grader to pull the unit downwards as it cuts.
The first cutting edge cuts into the material and rolls the material forward as it cuts (similar to a tidal wave at the beach). This rolling and mixing material flows over the front cutting edge assembly and is introduced into the material being cut, rolled and mixed by the back cutting edge.
Then the material flows over the back cutting edge assemble and out of the back of the grader. This cutting, rolling and mixing process is key to performance when it comes to pull type, twin blade graders and a major factor in this process is the pitch of the cutting edges.If a grader has too little pitch on the cutting edges, it will not cut effectively and material flows through without being rolled and mixed properly.
When this process of cutting, rolling and mixing is achieved properly by a grader, the material is sifted before it is relayed and the smaller material ends up on bottom and larger on top. This gives you the best possible compaction and also brings back up buried aggregate (rock, gravel, limestone, etc.) and keeps it on top of the road (or parking lot) surface.
When grading a road, it is essential to have a grader with the cutting edges on an effective angle. This angle will allow the grader to “slice” harder material as it is pulled and is essential in putting crown in a road. As the material flows through the grader, material is channels towards the center of the road (grading up the right and back down the left side the road just as you would drive a vehicle). Crown to a road is like a roof on a house. The pitch of the material prevents water from standing on a road which is the leading cause of ruts and potholes. When traffic hits water soaked material the material separates and has no strength. If enough crown is on a road surface, water does not have chance to stand long enough to penetrate deep into the road base.
It is not enough just to have the perfect cutting assembly on the precise pitch and on a functional angle.
We now come to another important feature in a twin blade, pull behind grader;
The cutting edge assembly is placed between two side pans which contains material to the width of the unit. The side pans must be tall enough to allow material to flow between the cutting assembly and the hitch. Also, there must be enough height in the side pans to give the grader a desired carrying capacity for material when the grader is adjusted to move material. These units can be adjusted by the top link of the tractor (manually or with optional hydraulics) to change the pitch of the cutting edge assembly allowing this graders to fill with material instead of material flowing through the unit.
The length of the side pans is also crucial. A grader needs enough length to keep the unit level while in use but short enough for the tractor to lift the grader.