Duncan Enviro 740, Owner'S Manual

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22
fig 26
1
Hints for Sowing with Variable Speed Gearbox
This gearbox allows for stepless changes in the speed of the
metering shaft and thus the seed rates. Due to the variations
in seed type and application rates there are 2 speed ranges
available.
By changing from High Speed to Low Speed the range of
settings and control is dramatically increased. The machines
are supplied ex the factory set to the high speed configuration.
Change to the Low Speed when the gearbox setting is down to
10 on the scale and the desired seed rate cannot be obtained.
To change the speed setting from high to low, remove the wing
nut and chain cover.
Release the tension on the chain (fig 23,1) by forcing back
the chain tensioner (fig 23,2) and hold in place with the crank
handle. Remove the chain from the 19 tooth output sprocket to
the 15 tooth sprocket, then remove the chain from the 15 tooth
gearbox sprocket to the 19 tooth. Check the chain is correctly
aligned then release the chain tensioner. Ensure the tension
roller is correctly aligned with the chain. Replace guard and
calibrate as required. Low speed set-up shown in fig 24.
To Determine the Gearbox Setting after a Speed
Change
For determining the correct gearbox setting after the speed
change, conduct the first test at 50. With the weight of seed
collected find your correct setting with the aid of the disc
calculator refer P 20, Fig 21.
Sowing of Fine Seeds
For sowing fine seeds the Enviro Drill is equipped as standard
with a combined normal and fine seed “Elite” metering wheel
(Fig 25/1).
During grain sowing and other larger varieties of seed both the
normal and fine seed metering wheels are coupled and both
rotate. In order to convert the seed drill to sow fine seed insert
the crank handle to rotate clockwise until the holes (Fig 25/2) of
the fine seed wheel are visible. Using the tool supplied (Fig
26/1) disengage the the pin inside the hole so that the normal
metering wheel rotates freely on the metering shaft.
At this time it would be advisable to close any shutter slides
not required for the fine seed sowing.
When seed is to be sown again using the normal metering wheel
press the pin, from the normal metering
wheel side (opposite direction to before),
using the tool, back into the hole of the fine
seed wheel thus reconnecting the drive
between the two.
High Speed
Low Speed
1
2
15T
19T
15T
19T
1
3
fig 23
fig 24
fig 25
2
1