One of the benefits of the new MacDon
R1 Series Disc Mower is that it features a unique cutter bar design which allows
the disc rotation pattern to be fully customized to suit both normal and
abnormal crop cutting conditions. MacDon disc mowers are factory configured
with the best disc rotation pattern, for optimal performance, in the widest range
of cutting conditions. However, if your crop conditions are either extremely
light or extremely heavy then it might be possible to further optimize cutterbar performance by reconfiguring the disc rotation pattern. Alterations to the
disc rotation pattern should not be undertaken unless there is a significant
amount of either extremely light or extremely heavy crop. There are four
possible disc rotation patterns on the R1 Series Disc Mower, with the most
commonly used patterns being either the one or three crop stream configurations. In pattern one, all of the discs rotate inward towards the center of the unit. In this
configuration, there is only one crop stream exiting the cutter bar which
offers optimum performance in light crop conditions. In pattern two, the outer discs
rotate inward while the center two discs counter rotate. This is a two crop stream
configuration that might offer slightly improved performance versus
configuration one. In pattern three, which is the factory configuration the outer two
discs on a 13 foot, or the outer three discs on a 16 foot, rotate inward, while
the remaining discs all counter rotate. This is a three crop stream
configuration that typically works well in heavy cutting conditions. In pattern
four, all of the discs on a 13 foot counter rotate, while on the 16 foot the
outer two discs rotate inward, and the remaining discs counter rotate. This four
crop stream is a consideration if cutting the heaviest of crops. There are
an even number of clockwise and counter clockwise oriented cutting assemblies
used on the cutterbar. The 13 foot has four of each while the 16 foot has five
of each assembly. On the bottom of the hub, you can see how the gear is offset
to the mounting ring. This allows the gear to contact the opposite idler gear
for a different rotation pattern. It is important to
ensure that each hub is always set to rotate in the same direction regardless
of where it is installed on the cutter bed. When we look at the two assemblies,
the one on the right hand side is a clockwise rotation assembly and is
identified by being smooth on the top of the shaft and the nut. On the left hand
hub assembly, notice the machined ring on the top of the shaft and the nut based
upon this we know that this is a counterclockwise rotating assembly. It is
important to keep the nut and the hub both of the same orientation because the
nut will rotate up on the threads when the shear pin is sheared. This allows the
cutting blades to clear each other in the event of shear pin breakage. Only one person should work on the cutter bed at a time to avoid unexpected movement of
the rotating parts. The disc mower should have the cutter bar raised off the
ground and the header angle tilted to the flattest guard angle. Engage both
safety stop valves to avoid injury. Shut off the engine. It is advised that the cutterbar be as clean as possible to avoid any
contamination of the cutterbar oil. Factory configured, R1 Series Mowers
have three crop streams to avoid confusion it might be helpful to label
the crop streams, label the rotation pattern on each disc. Remove the disc. If
installed the flange or spacer ring should be removed. Label the rotation
pattern of the inner drive hub. You will need to move both the drive hub and the
disc to the new position on the cutter bed. Caution should be used at all times
when removing the drive hub. Align the two cutouts in the hub with the
centerline of the cutter bed before removing the hub. You might require a
small pry bar to break the seal allowing the drive hub to be removed from the
cutter bed. Ensure that the o-ring remains with the drive hub and that it
doesn't remain on the cutter bed. Carefully switch the drive hub to its
new location using caution not to contaminate the cutter bed oil. This
clockwise rotating hub will continue to be clockwise rotating in its new
location. It is a good idea to do a temporary install of the disc to check
for proper balance and alignment before installing all the bolts on the housing. Now we rotate the disc to verify the correct timing. Timing is correct
when the disk is 90˚ to both adjacent discs. If a disk is out of time
half a tooth then we would correct by lifting the hub and rotate the spindle
180˚ to pick up on a different tooth. This will allow us a half tooth
adjustment. Be careful not to rotate the base and only rotate the spindle 180˚. Insure that the disk is at 90˚ to the adjacent disk. Reinstall
all hardware onto the drive hub in its new location. Tighten all hardware, and
torque the drive spindle hub bolts to 37 foot pounds or 50 Newtons install the
disk and torque the disk bolts to 63 ft/lb or 85 Nm. You can now
check your disk rotation pattern and each crop stream can be marked to ensure
that you have achieved your desired rotation pattern. MacDon R1 Series Disc Mowers are factory configured to a three crop stream
configuration which is the best overall disc rotating pattern in the widest
variety of crop conditions. The ability to customize the disc rotating pattern
allows MacDon customers greater flexibility for extreme drought
conditions or if operating in heavily irrigated high-volume crops. If you have
further questions about your MacDon R1 Series Disc Mower or about customizing your mower for your crop conditions then please contact your nearest MacDon
dealer or contact MacDon product support for further information.
