A Thai-made 108 kW rice combine harvester was modi"ed by replacing the cutter bar system with a stripper
header. The power requirement of the modi"ed machine was measured at no load and during "eld operation.
The stripper header system consisted of a 3 m wide stripping rotor, a metal hood and an adjustable nose. The
outer diameter of the stripping rotor was 450 mm. The stripping rotor consisted of eight rubber blades "xed on
an octagonal drum with each blade having 71 teeth. The work rate and harvesting losses were measured to
examine the "eld performance of the modi"ed machine.
Results obtained from the test showed that the power requirement for the whole machine during "eld
operation at 1600 min~1 was 58 kW. The threshing, traction and stripper header units consumed 11)4, 22)8 and
16)9 kW, respectively and the power transmission loss was 6)9 kW. For standing crop, the average "eld capacity
of the machine was 0)66 ha h~1 with a corresponding "eld e$ciency of 74%. In a lodged crop condition, the
average "eld capacity was found to be 0)3 ha h~1 with a corresponding "eld e$ciency of 72%. The total grain
loss of the machine was 4% of grain yield in the standing crop condition and 5)6% in the lodged crop condition.
No major mechanical or operational problems were observed during "eld operations.
( 2001