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==Combine - Current Work -- Desired Features of the Microcombine==
==Combine - Current Work -- Desired Features of the Microcombine==
This category is for grain and bean farmers to comment on the features they would find useful in this machine.
This category is for grain and bean farmers to comment on the features they would find useful in this machine.
Line 140: Line 139:
Zhejiang Shenmao Appliance Co., Ltd. Available at: http://shenmao.en.alibaba.com/product/250305412-209425313/43cc_small_Grain_Harvester.html . Accessed 25 March 2010.
Zhejiang Shenmao Appliance Co., Ltd. Available at: http://shenmao.en.alibaba.com/product/250305412-209425313/43cc_small_Grain_Harvester.html . Accessed 25 March 2010.


===== THE MINI COMBINE-HARVESTER: RESEARCH RESULTS AND A RELATED AUTOMATION CONCEPT=====
By Phan Hieu Hien (*), Le Van Ban (**)
(*) Center for Agricultural Energy and Machinery
Nong Lam University, Thu Duc, Ho Chi Minh City, Vietnam
E-mail: phhien@hcm.vnn.vn
(**) Faculty of Engineering and Technology
Nong Lam University, Thu Duc, Ho Chi Minh City, Vietnam
ABSTRACT
In Viet Nam, rice harvesting is a rising problem
due to shortage of manual labor during harvest.
Attempts to mechanize this operation using combine
harvesters encountered problems with soft soils,
frequent breakdowns, and lodged crops. Conventional
combine models weighs at least 1.2 tons and such
heavy units could not manage soft soils or “seemingly
dry” soils in the Mekong Delta.
A Chinese-originated lightweight mini-combine,
improved in several components by the Philippine Rice
Research Institute, was recently selected by the Nong-
Lam University Research Team on Combine, who
added and compared different wheel designs for wet
soft soils. In 2004, test results in several Provinces in
Viet Nam showed the performance of this model at
one ha per day capacity, cutting width is 1.2m, and
total grain losses is less than 2%. The combine
harvesting cost is 1/2 - 2/3 that of the current practice
of manual cutting and mechanical threshing. The light
weight of the machine (570 kG) proved to be an
absolute advantage in soft soils typical of the Mekong
Delta rice fields. Very soft soils leading to bogging
down could easily be overcome within minutes by
seven people. No other combine so far could allow
such troubleshooting. Thus, the design was
transferred to VINAPPRO, a manufacturer of engine
and machinery, which planned to manufacture 20 units
for the Spring harvest of 2005.
The resulted advantages pointed to a new
automation concept in combine operation: The
lightweight combine could be made even lighter in
operation. If the pooled operating weight of the combine
could be further reduced, then more trafficability and
mobility on very soft soils could be realized. This can
be simply done by removing about 120 kG of the two
operators (driver and bagger) from the combine, and
incorporating a device to conctrol the steering of the
machine from a short distane. Likewise, an automatic
bagging device replacing the manual bagger (who
used to sit on the machine) would reduce the total
weight. Together, 17% of weight in combine operation
could be reduced. Such scenario is not too
complicated in terms of automation circuit, and a plan
is underway to verify the concept.
INTRODUCTION
Rice harvesting in the Mekong Delta of Viet
Nam is still mostly done manually and thus is a rising
problem due to shortage of labor during harvest. Over
the past 20 years, among efforts to mechanize rice
harvesting in this region, combines have been
attempted by different government agencies as well
as the private sector, but failed to be accepted by
farmers.
This paper describes the adaptation work on a mini-
combine, including the testing of different versions, design
and selection of wheel systems for wet soils, and initial
promotional work in Southern Viet Nam; the information
draws heavily on an earlier publication (Tran Van Khanh
et.al. 2004). The second part of the paper presents a new
automation concept in combine operation by eliminating
the driver’s weight from the combine operation.
Review of literature: problems with combines
Thailand maybe the only country in South East
Asia with some success in adapting the combine.
There are about 8000 units of Western-style Thai-made
combine (with cutting width 2- 3m) in current use. In
other countries including Viet Nam, introduction of
such large combines have encountered three major
problems:
Soft soils
Most combine weights 1.2 – 2 tons (excluding
imported models of 4 – 11 tons). Such heavy machines
easily bog down in soft soils. Even during the dry-
season harvest, a seemingly dry field with a localized
soft spot can stop a heavy combine and make it
helpless in areas without access road for the rescue
vehicle. This is the main reason that have failed many
researchers and engineers in the area. One researcher
even concluded that there is no “dry soil” in the
Mekong Delta as far as the combine is concerned.
Many people now maitain that, for a large combine-
harvester to work, the field must be well irrigated and
drained, and should be large enough for the machine
to easily maneuver. This sounds logical, except that
the investment to implement such requirement for
combine operation is too big to be drawn from the
Nong Lam University Journal of Agricultural Sciences and Technology, No 4/2004
�
SCIENCE RESEARCH
agriculture itself, a condition for a sustainable progress
of a developing country. A more feasible option is to
develop a light-weight mini-combine that local
operators can easily pull out of soft sink spots if a
bogged-down situation occurs.
Frequent break-downs
Due to the single-unit fabrication with limited
resources, sometimes by village mechanics, combines
often fail under operation. Each break-down cost hours
or days to repair; one week’s time for repair could result
in significant lost income during the harvest season and
unreliability discouraged users to adopt such new
technology. This problem can be addressed through
improved manufacturing and continuous design
improvement with due consideration to added costs. A
workable initial design, a competent local manufacturer,
close monitoring of field operation, and after-sales service
support will help realize successful adoption of this new
technology.
Lodged crops
Rice lodging is often caused by extreme
climatic conditions such as typhoons or floods but
this is also related to the works of plant breeders and
agronomists. To date, attempts to develop a combine
that can harvest severely lodged crops have been
unsuccessful. Plant breeders and agronomists need
to improve lodging resistance of rice varieties.
However, a partially-lodged field area, say a 10%, still
means that 90% of the field is still readily available
for combine harvesting, especially if the combine is
small enough to circumvent around more severely
lodged spots that can be managed through manual
harvesting.
Thus, a suitable combine for local Viet Namese
conditions can be summarized into two basic
requirements: light weight and reliability.
MATERIALS AND METHODS
Design adaptation
Different surveys by the NLU Center for
Agricultural Energy and Machinery (CAEM) resulted
in a considerable database, including hundreds of
pictures. In 2003, the Philippine Rice Research
Institute (PhilRice) shared a design of a light-weight
mini-combine (570 kG), to continue a long tradition of
cooperation between NLU and the Institute in the area
of Agricultural Engineering. The project has been
sponsored by Briggs & Stratton Corporation, a well-
known gasoline manufacturer.
The first design of the mini-combine originated
in China. In 2003, PhilRice re-designed and improved
key functions adding significant improvements to the
prototypes, which were then transferred to NLU for
testing in Viet Nam. The new design is a typical
Western-type combine, with a reel wheel at the top of
a reciprocating cutting blades and a feeding crop auger
at the back of the cutter to feed a conveyor that brings
the cut plants towards an axial-flow thresher. The
cleaning of paddy is done beneath the thresher
concave by an oscillating screen and a fan, similar to
the IRRI axial-flow threshers, before the paddy grain
is conveyed upwards for bagging. The combine is
powered by a 16-HP B&S gasoline engine (weighing
40 kG), which is commonly used for axial-flow
threshers in the Philippines.
In Viet Nam, design adaptation by the NLU
included: a) identifying areas for strengthening and
optimizing design performance and reliability; and b)
comparing different wheel designs for wet soft soils.
The NLU believes problems of combine harvesting in
Viet Nam are “of the earth, and not of the air”, that is
to say, they are more concerned on soil and wheel
interactions rather than the working principles and
components which are already common knowledge.
a) b)
Figure 1. a) The -mini-combine prototype from PhilRice.
b) Mini-combines in DongThap; both units are made by Vinappro.
Journal of Agricultural Sciences and Technology, No 4/2004 Nong Lam University
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SCIENCE RESEARCH
After evaluation and further “fine-tuning” of the
prototype, the design was transferred to the Viet Nam
Agricultural Power Company (VINAPPRO), a leading
manufacturer of diesel engines and other machinery
who then fabricated two units for local field testing
and evaluation.
Testing
The mini-combines (one from PhilRice and two
from Vinappro) have been tested in five locations in
the Mekong Delta and Eastern Provinces from March
to October 2004, including exploratory test,
performance tests in semi-wet and wet conditions,
durability test.
Seven different traction types and variations
were tested for trafficability, namely: 1) rubber tyres,
2)dual rubber tyres, 3)steel cage wheel, 4)original
pyramid-shaped lug wheel with 10 lugs/wheel,
5)pyramid-shaped lug wheel with12 lugs/wheel, 6)wider
pyramid-shaped lug wheel with 12 lugs/wheel, and
7)retractable lugs mounted to rubber tyre.
Standard test instruments, such as stop watch,
tachometer, scales and a penetrometer (ASAE, 1994)
to measure the hardness of soil, were used in the
tests.
Automation concept
The positive test results prompted to a new
automation concept in combine operation: The
lightweigt combine could be made even lighter in
operation. If the pooled operating weight of the combine
could be further reduced, then more trafficability and
mobility on very soft soils could be realized. This can
be simply done by removing about 120 kG of the two
operators (driver and bagger) from the combine, and
incorporating a device to conctrol the steering of the
machine from a short distane. Likewise, an automatic
bagging device replacing the manual bagger (who
used to sit on the machine) would reduce the total
weight. Together, 17% of weight in combine operation
could be reduced. Thus, work efforts on developing
device to realize this automation concept are under
way, with some initial results.
RESULTS AND DISCUSSION
Field performance
The field tests were conducted under different
soil and crop conditions. The performance and
specifications of the combine are summarized in Table
1. Average harvest was one hectare per day. The total
losses ranged at 1.0 – 1.4 per cent, and never
exceeded 2 per cent. (Table 1)
Trafficability
Our tests indicate that, on dry soils, the rubber
tyre is most suitable in terms of both traction and
vibration of the machine. However, in soft and wet soils,
the rubber tyres sank and bogged down the combine.
Two types of wheels were found to be suitable:
1) The pyramid-shaped lug wheels could
manage soft soils with penetration resistance of more
than 0.4 MPa.
2) The retractable lugs mounted to rubber
tyre proved to be most useful in soft soil. The rubber
tyres provide floatation, while the lugs provide both
traction and flotation.
Table 1. Mini- combine performance and specifications (Tran Van Khanh et.al. 2004)
Working width: 1.2 m maxmum
Working speed: 1.5 – 2.1 km/hr
Idle travel speed: 2.0 – 5.0 km/hr
Working time utilization efficiency: 70 – 80 %
Field capacity: 1 ha /day (0.9 – 1.3)
Cutting height: Adjustable 0.1 – 0.4 m
Combined losses (shattering,
unthreshed and separating): < 2.0 %
Power requirement: 16-HP B&S gasoline engine
Fuel consumption: 15 Liter/ ha
Labor requirement: 5: one driver, one bagger, and three haulers of grain
bags to levees.
Traction: Semi-dry soil:
Soft, wet soil:
Rubber tyres 6.00 x 12
Pyramid-shaped lug wheel, or
Retractable lugs + rubber tyre
Overall dimensions (L x W x H): 3.5 m * 1.5 m * 1.5m
Net weight: 570 kg
Nong Lam University Journal of Agricultural Sciences and Technology, No 4/2004
�
SCIENCE RESEARCH
On soft soils, the light weight of the combine
proved to be an absolute advantage. If the machine
was about to sink, the bag laborer in the rear seat
could dismount temporarily to reduce machine weight,
thus allowing the mini-combine to pass through soft
spots while maintaining operation. This suggests that
any additional weight (i.e. from alternative heavy diesel
engines) would pose major problems on soft soils and
also re-confirms why one-ton-plus combines could not
work so far.
During the test on extreme soft soils leading to
occasional bogging down, the problem was overcome
within minutes by eight people, who simply pulled
back the combine out of the troubled spot.
Reliability
The mini-combine have been operated on 12
hectares to date. Breakdowns and troubles occurred,
such as shear of cotter pin of the steering wheel, failure
of the rear U-fork..., but these were considered minor
and were right away fixed in the field or by small village
mechanics.
Cost comparison to current harvesting methods
Although the actual unit cost from the
production line is not yet available, the estimated sale
price is 41.000.000 VND (H” US$2600). Based on
test data and assumptions usually made for cost
calculations, the harvesting cost for 1 hectare using
this combine is 361 000 VND or about US$23, of which
35% are for depreciation-interest-repair, 34% are for
gasoline, and 31% are for labor. How is this cost
compared to current harvesting methods ?
The most practiced harvesting method in the
Mekong Delta of Viet Nam is manual havesting +
mechanical threshing. Depending on the province, rice
yield, and cropping season, the total cost in 2003 of
existing methods ranged from 700 000 to 900 000 VND
per hectare, with 60% representing harvesting costs
and 40% for threshing costs.
Thus a total cost of 361 000 VND/ha with the
mini-combine represents a cost reduction of 48 to 60
percent, compared to current practices. This is
significant, considering that this saving is equivalent
to about 15% of the profit from a typical hectare of
rice.
Moreover, labor cost decreases appreciably
with use of the combine. The current harvesting and
threshing system normally requires dozens of laborers
and 150 man-hours per hectare, which is now reduced
to five people and 40 man-hours per hectare with the
combine.
In summary, Test results showed both the
technical and economic feasibility of the mini-combine
under Vietnamese conditions. The outstanding
advantage of this combine lies in its light weight, which
enables the trafficability in typical soft soils of the
Mekong Delta.
A CONCEPT IN COMBINE AUTOMATION
The above resulted advantages pointed to a
new automation concept in combine operation: The
lightweigt combine could be made even lighter in
operation. If the pooled operating weight of the
combine could be further reduced, then more
trafficability and mobility on very soft soils could
be realized. The idea stemmed from our
observations in the field tests. In some very soft
soils wherein the combine was about to bog down,
the bagger-laboror jumped out of his seat and
walked along, then the trafficability improved, and
the combine surpass the obstacled soft soil. In
worse situation, the driver had to jump down too
and steer the combine walking alongside until better,
harder soil was present.
The implication is that even 120 kG of the
two operators, or even about 60 kG of the bagger is
accountable for the trafficability of the combine.
Thus, if we remove these operators’ weight from
the combine, and incorporate a device to conctrol
the steering of the machine from a short distane,
then the combine mobility would be improved.
Likewise, an automatic bagging device replacing
the manual bagger would reduce the total weight.
Together, 17% of weight in combine operation could
be reduced. Such scenario is not too complicated
in terms of automation circuit. The following
schematic diagram and description serve to
illustrate the concept.
Control objectives
The objectives to control the combine operation
are as follow:
-Control of the reel height
-Control of the cutter bar height
-Control of the engine speed
-Control of the forward speed (high or low)
-Control of the turning (left or right)
-Control of the stopping (open or close)
Journal of Agricultural Sciences and Technology, No 4/2004 Nong Lam University
�
SCIENCE RESEARCH
A plan is underway to verify
the concept and operation.
Tieán
(Forward)
Reõ phaûi
(Turn right)
Reõ traùi
(Turn left)
luøi
(Reverse)
Thaáp (Low)
Cao (High)
Toác ñoä
ñoäng cô
(Engine
speed )
Phanh
(Brake)
Ñoùng
(Close)
(Gear box)
Soá
(1)
(2) (4)
(3)
Reel
Air Cylinder
Cutter bar
Air cylinder
Figure 2. Block schematic diagram of remote control for mini combine harvester
Selected method for control system
A total of 10 actuators would be needed.
Three different methods were evaluated: by high
pressure air, by servo-motors, and by hydraulic
system. Considering the cost, ease of installation
and operation, and reliability, the air pressure
system was selected. The control is by the remote
cable, with the operator walking along or at a
distance with the combine; the power source is a
DC 12 volt system. The drawback is a compressor
is needed, and the advantages are ease of control,
component parts are easily available.
The block schematic diagram of remote control
for mini-combine is shown in Figure 2.
CONCLUSION
A newly designed mini-combine has been
successfully adapted in Viet Nam. Data for its
technical and economic performance seems to be
favorable for local acceptance of this new technology.
The outstanding feature of this combine is its very
light weight, which enables its mobility on soft soils
and difficult access roads, a fact rarely achieved by
other hevier combines. A campaign is underway to
commercialize this mini-combine in Viet Nam for the
winter-spring harvest of 2005. The first batch of 20
combines will be launched to farmer-users at this time.
Continuing in the direction of making the
combine as light as possible to keep the maximum
mobility, a new design concept in combine automation
has been put forward with the aim of removing the
operators’ weight during operation of the combine.
Different scenarios with different alternative setup are
planned to be evaluated to verify the concept.
ACKNOWLEDGEMENT
The support for the design, testing, and
promotion in various ways from Briggs&Stratton Inc
(Wisconsin), and from VINAPPRO Company (Dong-
Nai) is gratefully acknowledged. PhilRice is
acknowledged for sharing the initial design of the mini-
combine.
REFERENCES
ASAE. 1995. ASAE Standards 1994. American Society
of Agricultural Engineers, St. Joseph, Michigan, U.S.A.
BARDAIE M.Z. 1980. Economic farm size for rice
combine harvester in Malaysia. Agricultural
Mechanization in Asia, Autumn 1980 pp.49- 52.
Nong Lam University Journal of Agricultural Sciences and Technology, No 4/2004
�
SCIENCE RESEARCH
BAUTISTA, E.U. and A. SCHMIDLEY. 2004. PhilRice-
B&S Collaboration: Building partnerships across Asia.
Paper presented at the Philippine Rice R&D Conference,
PhilRice, Maligaya, Munoz, Nueva Ecija. 114-16 April
BENSON E.R., J.F. REID, Q. ZHANG. 2003. Machine
vision-based guidance system for an agricultural small
grain harvester. Transactions ASAE Vol.46 (4) 12551264.
PHAN HIEU HIEN. 1991. Development of the axial-
flow thresher in Southern Vietnam. Agricultural
Mechanization in Asia J. Vol.22 No.4 pp.42-46.
SUZUKI M. 1980. Performance of rice combine
harvesters as evaluated by the national test in Japan.
Japan Agricultural Research Quarterly Vol.14 No.1
pp.20-23.
TRAN VAN KHANH, PHAN H. HIEN, E. BAUTISTA,
A. SCHMIDLEY, K.LEE, MAI D. BAN. 2004. Testing
and promotion of a rice mini-combine in Viet Nam.
Proceedings of the Mekong Rice Conference,
organized in HoChiMinh City, Viet Nam, 15- 17
October 2004.
Journal of Agricultural Sciences and Technology, No 4/2004 Nong Lam University
===== Development of rice combines in Viet Nam=====
Phan Hieu Hien, Tran Van Khanh# # , Graeme R. Quick ***
E-mail: phhien@hcm.vnn.vn
This is not a peer-reviewed article.
Electronic-only Proceedings of the International Conference on Crop Harvesting
and Processing, 11-14 February 2007 (Louisville, Kentucky USA)
Publication Date, 11 February 2007.
ASABE Publication Number 701P0307e
ABSTRACT
Rice combine development in Viet Nam, especially in the Mekong Delta in the South, has been a
slow process. Mechanized farm equipment is accepted only if it matches local agricultural
conditions technically and economically. Earlier attempts at bringing in or developing combines
by Central research institutes, Provincial factories, and farmer-mechanics were unsuccessful at
actual scale operation. Three main problems were encountered over the past 20 years:
(1) Machines working in soft paddy fields bog down, especially heavy Western-style combines.
(2) Reliability at lowest cost is critical; delays caused by machine breakdowns result in significant
lost income during the harvest, and unreliability discourages users from adopting new technology.
(3) Harvesting severely lodged rice crops is challenging, not so much as an engineering problem
as it is a matter of plant breeding and varietal selection to improve lodging resistance.
Nevertheless there has been intensive development in the past 5 years by as many as 15 small-
scale Vietnamese manufacturers. One mini-combine manufacturers has lately sold 90 units to
private farmers across the country. In 2006 a combine contest was organized by the Vietnamese
National Testing Agency. Three designs were given “accredited recognition awards”, meaning
recognition for future promotion through the governmental Extension system. The recent
development of mini-combines follows.
Keywords: Combine, Rice Harvesting, Mechanization
INTRODUCTION
Viet Nam is an agricultural country with 82 millions (M) inhabitants in 2005, of which 61 M are
in rural households. Rice is the most important crop, cultivated on 80 % of the total farm area,
and rice accounts for 85 % of the country’s food grain output. In 2003 , Viet Nam produced 35
M ton of paddy on 4.2 M ha of rice land. This total production was four times more than that of
1976. Viet Nam is the world’s third largest rice exporter. For the past 10 years, the export of rice
has been 3 – 4 M tonnes a year.
The Mekong Delta in Southern Viet Nam , with 2.7 M ha of rice land, is producing about 50 %
of Viet Nam total rice output. With only 17 % of the total population, this region has accounted
for more than 90 % of Vietnamese rice export in the past decade. Average farm size is about 1
#
Paper for presentation at the International Conference on Crop Harvesting and Processing,
February 11-14 2007, Louisville, Kentucky.
# # Lecturers, Nong-Lam University (formerly: University of Agriculture and Forestry), HoChi-
Minh City, Viet Nam,
*** Consulting Engineer (Queensland, Australia) and Former Head, IRRI Agricultural
Engineering, Philippines.
�
ha per household, although in some newly-reclaimed districts, 3 - 10 ha per household is not
uncommon.
Rice harvesting in the Mekong Delta of Viet Nam is still mostly done manually, but threshing
was completely mechanized. Over the past 20 years, effort to introduce rice harvest equipment
in this region have been attempted by different government agencies as well as the private sector,
from central research institutes to skilled village mechanics. Different alternatives have been
tried, i.e. the reaper or the combine, but these either failed or were only half-way solutions to the
problem.
This paper describes the slow process of combine development in the Mekong Delta, identifies
affecting factors and related problems. Details of the work on a mini-combine, including wheel
systems for wet soils, and promotion to the industry for manufacturing are presented.
CURRENT STATUS OF RICE HARVESTING AND PROBLEMS
In the Mekong Delta of Viet Nam, as in various parts of South-East Asia, rice harvesting is
mechanized to varying degrees beyond traditional manual methods. Three types of mechanized
harvesting are:
1)
Manual harvesting + mechanical threshing. More than 95% of rice is threshed mechanically
by the axial-flow thresher (Phan H. Hien 1991). However, due to lack of technically suitable
and economically viable methods of mechanically cutting rice plants, local people continue
to harvest rice manually with a sickle.
Figure 1: (a) Rice reaper, made by Long-An Mechanical Factory in 1985…
(b)
… and one from 3 major reaper manufacturers remaining in 2004;
(c)
A combine made by a farmer-mechanics in Dong-Thap Province;
(d)
An imported combine under test in 1998.
2
�
2) Mechanical reaper + mechanical threshing. The Chinese windrower reaper was introduced to
South-East Asia through the International Rice Research Institute (IRRI) way back in the
1980’s. The IRRI-designed reaper was introduced to Viet Nam in 1984 by the University of
Agriculture and Forestry (now renamed Nong-Lam University NLU). Commercialization of
the reaper (Figure 1a) peaked in around 1988 with about 15 manufacturers but there remain
only three manufacturers producing 100-200 units per year each in the year 2000. (Figure 1b)
Reaper adoption did not expand rapidly because it was only a partial solution. Manual
gathering of the cut windrows still cost about 2/3 of the traditional hand cutting-gathering.
Besides, the long-length cut of the plants is less suited to mechanical threshing, unlike
manually harvested crops.
3) Combine. (See Next Section)
COMBINE DEVELOPMENT
Unlike Thailand, the only country in South-East Asia with some success in adapting the combine
(with about 8000 units of Western-style Thai-made units in use), the introduction of such large
combines have encountered three major problems in Viet Nam:
(1) Soft soils. Most local combine weights 1.2– 2 tonnes while imported models weigh 4– 11
tonnes. Such heavy machines easily bog down in soft soils. Even during the dry-season
harvest, a seemingly dry field with a localized soft spot can render a heavy combine helpless
in areas which may not have access roads for a rescue vehicle (Fig.1c and 1d). This is the
main reason that has failed many researchers and engineers; one researcher has even
concluded that there is no “dry soil” in the Mekong Delta as far as the combine is concerned.
Many people now maintain that, for a large combine-harvester to work, the field must be
well irrigated and drained, and should be large enough for the machine to easily maneuver.
This sounds logical, except that the investment to implement such requirement for combine
operation is too big to be drawn from the agriculture itself, a condition for a sustainable
progress of a developing country.
(2) Frequent break-downs. Quality is often lacking in one-off manufacture by village
mechanics, and such combines breakdown. Each break-down cost hours or days to repair; a
week’s repair time means significant lost income during the harvest season. Unreliability
discouraged users from adopting new technologies. Thus, reliability at lowest cost is critical.
The frequent breakdown of combines can be addressed through improved manufacturing and
continuous design improvement with due consideration to added costs. A workable initial
design, competent local manufacturer, close monitoring of field operation, and after-sales
service support are all essential for the realization of a new technology.
(3) Lodged crops. Rice lodging is often caused by extreme climatic conditions such as typhoons
or floods and attempts to develop a combine that can harvest severely lodged crops have
been unsuccessful. Plant breeders and agronomists need to improve lodging resistance of rice
varieties. However, a partially-lodged field area, say 10 % lodged, means that 90 % of the
field is still available for combine harvesting, particularly if the combine is small enough to
circumvent severely lodged spots that can be manually harvested.
These are the three reasons why combine development in the Mekong Delta of Vietnam has
been slow over the past 20 years. Things are changing however in the last 5 years.
3
�
1980- 1999
Between 1980 and 1999, several combines were developed by Central research institutes,
Provincial factories, and even farmer-mechanics. Attention was focused in 1997 when the
Vietnamese Ministry of Agriculture organized a combine contest in Can-Tho Province, the heart
of the Mekong Delta. Seven models participated, several locally made combine that were
heavier than 2 tonnes, and one 5-tonne European combine. All bogged down in soft soils, except
for a second-hand Japanese head-fed combine that weighed around 1 tonne. All bogged down in
soft soils, except one second-hand Japanese head-fed combine weighing around 1 ton. About ten
of these “light weight” combines were later sold by some trading companies. But these secondhand
units quickly broke down in the first harvest season; spare parts were not available as they
had been no longer fabricated in Japan; so these combines were junked. Among “best” locally
made combines, the manufacturer was able to sell a few units; but again after one harvest season,
buyers returned the machine to the manufacturer because of frequent breakdowns; each time
requiring a severak critical days for repair. A one-week downtime meant that half of the peak
harvest season was missed in the area. That meant significant lost harvest income as rice quality
deteriorates when not harvested at the optimal time (Quick, 2003).
2000- Present
Since 2000, the Vietnamese economy has demonstrated rapid growth, and as a consequence
harvest labor has become a serious problem. Rural people prefer higher-paying jobs at
construction sites or other industrial jobs. This has motiovated researchers and manufacturers to
renew efforts at promoting combines, this time with experience learnt from the earlier efforts.
From 2000, about 15 small-scale combine manufacturers have tried their products. A combine
contest was organized in 2006 by the Vietnamese National Testing Agency (Fig. 2). Eight local
models and one Chinese imported model presented. Unlike the previous contest, these machines
had been used by the manufacturers for harvesting their own rice or else extensively tested.
Some manufacturers had sold up to a dozen units before entering the contest. From the contest,
three designs were given “accredited recognition awards”, meaning recognition and future
promotion through the governmental Extension system. Two winners were the local Chin-
Nghia 1500-kg combine, and a 2300-kg Chinese imported combine. The third was a 600-kg
“mini-combine” with several distinctive features, which are described in the following Section.
Figure 2: Combines at the contest in Can-Tho Province, 2006.
4
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THE MINI-COMBINE
Design
The NLU Center for Agricultural Energy and Machinery (CAEM) was established in 2001 and
began research to improve rice harvesting methods and conditions in Viet Nam. Different
surveys resulted in a database, including hundreds of pictures. In 2003, the Philippine Rice
Research Institute (PhilRice) shared a design of a light-weight 600 kg mini-combine, to continue
a long tradition of cooperation between NLU and the Institute in the area of Agricultural
Engineering. The mini-combine project was sponsored by Briggs & Stratton Corporation, a U.S
leading gasoline manufacturer.
The initial design came from China. In 2003, PhilRice re-designed and improved key functions
adding significant improvements to the prototypes, which were then transferred to NLU for
testing in Viet Nam. This is based on a tricycle undercarriage, and uses a Western-style
combine open front gathering head (Fig. 2a), to feed a conveyor that brings the cut plants
towards an axial-flow thresher. The cleaning of paddy is done beneath the thresher concave by
an oscillating screen and a fan, similar to the IRRI axial-flow threshers (Quick, 1998), before the
paddy grain is conveyed upwards for bagging (Bautista &Schmidley 2004). The combine is
powered by a 16-HP B&S gasoline engine that weighs 40 kg.
In Viet Nam, design adaptation by the NLU included: a) identifying areas for strengthening and
optimizing design performance and reliability; and b) comparing different traction wheel designs
for wet soft soils. The NLU believes problems of combine harvesting in Viet Nam are “of the
earth, and not of the air”, that is to say, they are more concerned about soil and wheel
interactions rather than the working principles and components which are already common
knowledge.
After evaluation and further “fine-tuning” of the prototype, the design was transferred to the Viet
Nam Agricultural Power Company (VINAPPRO), a leading manufacturer of diesel engines and
other machinery, who then fabricated two units for local field testing and evaluation, before
deciding to go on with mass production.
Testing
In 2004, the mini-combines were tested in different provinces, first for exploring the working
capabilities of the PhilRice unit (Fig.3a), then for measuring the performance of the Vinappro
units in wet conditions (Fig.3b), and for durability evaluation
Seven different traction types and variants were tested for trafficability (Figures 4), namely:
1)rubber tyres, 2)dual rubber tyres, 3)steel cage wheels, 4)original pyramid-shaped lug wheels
with 10 lugs/wheel, 5)pyramid-shaped lug wheels with12 lugs/wheel, 6)wider pyramid-shaped
lug wheels with 12 lugs/wheel, and 7)retractable lugs mounted next to rubber tyre.
Standard test instruments and a penetrometer (ASAE 1994) to measure the hardness of soil, were
used in the tests.
Results
The performance and specifications of the combine are summarized in Table 1 (Tran V. Khanh
et.al 2004); the field tests were conducted under different soil and crop conditions. Average
5
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harvest was one hectare per day. The total losses ranged at 1.0 – 1.4 per cent, and never
exceeded 2 per cent.
(a) (b)
Figure 3: a) The 600-kg mini-combine prototype from PhilRice (Tran V. Khanh et.al 2004).
b) Mini-combines in DongThap; both units are made in Viet Nam by Vinappro.
Table 1: Mini- combine performance and specifications
Working width : 1.2 m maximum
Working speed : 1.5 – 2.1 km/hr
Idle travel speed : 2.0 – 5.0 km/hr
Working time utilization efficiency : 70 – 80 %
Field capacity : 1 ha /day (0.9 – 1.3)
Cutting height : Adjustable 0.1 – 0.4 m
Combined losses (shattering, unthreshed
and separating) : < 2.0 %
Power requirement : 16-HP B&S gasoline engine
Fuel consumption : 15 Liter/ ha
Labor requirement : 5: one driver, one bagger, and three
haulers of grain bags to levees.
Traction: Semi-dry soil :
Soft, wet soil :
Rubber tyres 6.00 x 12
Pyramid-shaped lug wheel, or
Retractable lugs + rubber tyre
Overall dimensions (L x W x H) : 3.5 m * 1.5 m * 1.5m
Net weight: 600 kg
Trafficability Tests, among the 7 types of wheels:
The tests indicated that, on dry soils, the rubber tyres were most suitable in terms of both traction
and vibration of the machine. However, in soft and wet soils, the pyramid-shaped lug wheels
(Fig. 3a) could manage soft soils with penetration resistance of more than 0.4 MPa. The
retractable lugs mounted to rubber tyres proved to be the most useful in soft soil. Rubber tyres
provided floatation, while the lugs provided both traction and flotation (Fig.3b).
On soft soils, the light weight of the combine proved to be an critical advantage. If the machine
was about to sink, the bag laborer in the rear seat could jump off temporarily to reduce machine
load, to allow the mini-combine to pass through soft spots while maintaining operation. In
extremely soft conditions where there was occasional bogging down, the problem was overcome
6
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within minutes by seven people, who simply lifted and pulled the combine out of the trouble spot
(Fig. 3f). No other combines could be managed that way!
As for reliability, the mini-combine was operated on 15 hectares, before transferring the design
to industrial production. During the tests, breakdowns and troubles occurred, such as shear of
cotter pin of the steering wheel, failure of the rear U-fork..., but these were considered minor and
were immediately fixed in the field or by small village mechanics. Nevertheless, this indicates
more attention is needed during local manufacturing.
Figure 4: (a) The pyramid-shaped lug wheel; (b) Retractable lugs mounted adjacent to rubber tyre;
(c) Dual tyre blocked with clay; (d) The cage wheel; (e) The combine is easily lifted for changing wheels;
(f) Bogged-down combine on soft soil was simply pulled out by 7 people. (Tran V. Khanh et.al 2004).
7
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Mini-combine commercialization
The VINAPPRO Company produced a total of 90 units between 2005-2006. Apart from a few
units that went to state agencies for extension, the majority of these combines were bought by
private farmer-contractors with their own money. Four users placed repeat orders, each for a
second unit after the first unit had harvested some hundreds of hectares. All these are positive
indicators that the mini-combine is following the well-known mechanization pattern in the
Mekong Delta, where the machine is owned by the service provider. A small farmer owning
only 1 ha buys an 80-HP tractor, plows his field for one day or less, and next plows for 100 other
farmers on a contract basis. In the same way, the contractors harvest, thresh and dry paddy.
Cost calculations
In 2006, the sale price of a mini-combine from the production line was US$ 2900 ###. Other
data and assumptions are listed in Table 2 for estimating the cost of machine use.


Table 2: Data and assumptions for estimating the cost of machine use (Tran V. Khanh et.al 2004).
Purchase price : US$ 2900 (˜ 46 000 000 VND)
Life : 3000 hours / 6 years (#1)
Interest rate : 10 % / year
Working capacity : 1.0 ha /day
Fuel consumption (gasoline) : 15 Liter /ha
Fuel price US$ 0.63 / liter
Lubricants and filters… (as % fuel cost): 15 % fuel
Labor: Driver: (Number) * Daily wage: (1) * US$ 2.2
Bagger &Hauling laborer: (Number) * Daily wage: (4) * US$ 1.6
Total Repair & M. cost ( as % Purchase price): 40 %
Note: (#1) 3000-hr life ˜ 6 yrs * 3 crop seasons/ year * 17 days/ season * 10 hrs/ day.
Based on the above data, cost of using the mini-combine is calculated and summarized in
Table 3 and Figure 5.
### For the convenience of overseas readers, all monetary numbers in Vietnamese Dong
are converted to US$, with the conversion rate in 2006: 1 US$ ˜ 16 000 VND
8
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Table 3: Cost of use for the mini-combine
Cost US$ /ha
Depreciation 5.3
Interest 1.6
Gasoline 11.8
Labor 7.2
Repair 2.1
Total
US$ per hectare
27.6
˜
28
Cost of use, Mini-combine
Deprecia
Repair
tion
19%
Labor Interest
26% 6%
41%
Gasoline
8%
Figure 5: Distribution of utilization cost ( Total = US$ 27.6 )
Comparing Costs with current harvesting methods
The most common harvesting method in the Mekong Delta of Viet Nam is manual harvesting +
mechanical threshing. Depending on the province, rice yield, and cropping season (dry or wet
harvest), the total cost in 2004 of existing methods ranged from US$ 45 to 60 per hectare, with
about 60% representing cutting and gathering costs and 40% for threshing costs.
Thus the total cost of US$ 28 /ha for the mini-combine represents a substantial cost reduction of
38 to 53 percent, compared to current practices. This is significant, considering that this saving
alone is the equivalent of 15% of the profit from a typical hectare of rice.
Moreover, the labor requirement is appreciably reduced by the combine. The current harvesting
and threshing system normally requires dozens of laborers and up to 150 man-hours per hectare,
against five people and 40 man-hours per hectare with the combine.
9
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CONCLUSIONS
Rice combine development in the Mekong Delta of Viet Nam over the past 20 years has been a
slow process, following the introduction of axial threshers and reapers. Three problems affect
the combine adoption: (a) soft soils; (b) machine reliability, and (c) lodged rice crops. Early
attempts in the 1980’s and 1990’s by different agencies and the private sector were unsuccessful
at actual scale operation. Since 2000’s severe labor shortage for rice harvesting has prompted
intensive development by several small-scale combine manufacturers. Three combine brands
gained the “accredited recognition awards” during a combine contest in 2006; these 3 companies
have commercialized their combines. Particularly, the Vinappro Company has sold 90
mini-combines. This 600-kg combine was adapted from an initial design from China, with
modifications of the cleaning system by PhilRice. Durability testing and improvement of the
wheels for soft soils were made by NLU in Viet Nam before transferring the design to industry.
The combine represents a good step forward in Viet Nam.
Acknowledgements
The authors wish to thank Dr. Wesley Buchele for his encouragement to submit this paper for
ASBAE 2007 International Conference on Crop Harvesting and Processing.
REFERENCES
ASAE. 1995. ASAE Standards 1994. American Society of Agricultural Engineers, St. Joseph,
Michigan, U.S.A.
BAUTISTA, E.U., A. SCHMIDLEY. 2004. PhilRice-B&S Collaboration: Building partnerships
across Asia. Paper presented at the Philippine Rice R&D Conference, PhilRice, Nueva Ecija.,
April 2004.
PHAN HIEU HIEN. 1991. Development of the axial-flow thresher in Southern Vietnam.
Agricultural Mechanization in Asia J. Vol.22 No4 pp.42-46.
QUICK, G.R. 1998. Global assessment of power threshers for rice. Agricultural Mechanization
in Asia J. Vol.29 No3 pp.47-54.
QUICK, G.R. 2003. Rice Harvesting. Chapter pp 491-542, in: Rice. The Monograph, by Wiley
& Sons, New York.
TRAN VAN KHANH, P.H. HIEN, E. BAUTISTA, A. SCHMIDLEY, K. LEE, M.D. BAN.
Testing and promotion of a rice mini-combine in Viet Nam. Proceedings of the Mekong Rice
Conference, HoChiMinh City, Viet Nam, 15- 17 October 2004.
10


== Combine - Sign-in==
== Combine - Sign-in==
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*John
*John
*[[User:Mjn]]
*[[User:Mjn]]
=See Also=
*[[Combine Research Paper]]
*[http://www.indiamart.com/north-agro-industries/tractor-combine.html Tractor Combine]
*[http://www.firstbtob.com/products/1143108/Wheat-Combine-Harvester-mounted-on-the-tractor.html Wheat Harvester]

Revision as of 08:06, 5 September 2011

Combine - Current Work -- Desired Features of the Microcombine

This category is for grain and bean farmers to comment on the features they would find useful in this machine.

I'm new and a little hesitant to make edits without knowing more of how things work, but...

I'm a very small-scale farmer who has been very frustrated by the lack of an appropriate scale combine.

Observations:

1. The Allis-All Crop appears to be nearly ideal. (http://www.yazallcrop.com/) I don't know what the status of the IP is for them, but it seems to me there is an opportunity there in modernizing the design in minor ways and making both new replicas and parts for the older machines which still exist.
2. When raising small grains on a small scale, threshing is the chief bottleneck. I'm willing and able to cut enough wheat with a scythe to feed my extended family, but threshing is another question. It is very laborious and time consuming.
3. Some Amish farmers are said to use combines permanently parked as fixed threshing machines.
4. What I'd like best would be a modular design where I could buy or build the thresher first, then the cleaner, then the cutter bar and pickup wheel in a trailer configuration, then a self-propulsion unit and bolt each one on as it is ready. In my case I'd probably use it towed and never make that last step.
5. Bear in mind that agriculture is similar in boot-strapping to this whole project and it is important to be able to get some functionality early (the thresher in this case) and then build on it as resources come on line.
6. I'm not as familiar with the all crop as I'd like to be, but I believe it needs a special head to pick corn (maize). I'd call corn picking a "nice to have" which if it could be integrated easily would be fine but otherwise, since it can be managed in so many other ways, should be a very low priorty.
7. Since old grain and dirt is very damaging to the device, easy cleaning should be an important consideration.
8. A design which leaves the straw windrowed for easy loading or baling is highly desirable.

Combine - Current Work -- Survey of Existing Commercial Models

Small Scale Grain Production Today -- this link is to an article at the website of a commercial dealer in imported European machinery. He has some pictures of stationary threshers that run $5K - $26K. There is a survey of commercial small combines presently being manufactured in Europe and Japan. These small combines retail for $40K - $77k. http://www.ferrari-tractors.com/smallscale.htm

Here is a bean thresher retailing for $9500 without an engine, $11000 with an engine -- http://www.ferrari-tractors.com/PDF%20Articles/Bean%20Threshers%20with%20pictures%20oct%202003.pdf

Article on lower cost small grain harvesting. http://www.ferrari-tractors.com/PDF%20Articles/Grain%20Harvesting%20Options.pdf

Small scale bean harvesting http://www.ferrari-tractors.com/PDF%20Articles/Small%20Scale%20Bean%20Harvesting.pdf

Small scale threshing equipment. http://www.ferrari-tractors.com/PDF%20Articles/Small%20Scale%20Threshing%20Equipment.pdf

Grain harvesting alternative technology http://www.ferrari-tractors.com/PDF%20Articles/Grain%20Harvesting%20Alternative%20Technology.pdf

http://www.ferrari-tractors.com/smallscale.htm

Small grain harvester http://www.youtube.com/watch?v=dJBcwNMWvRE&feature=grec_index http://www.croplandbiodiesel.com/images/clb-brochure-English-2010.pdf (GO TO PAGE 5 FOR COMBINE SPECS)

ZURN Rocket: http://www.youtube.com/watch?v=rVuBEO-863Q

Massey Ferguson 31: http://www.youtube.com/watch?v=oLkh8qoIrHo&feature=related

Combine - Developments Needed

Combine - General

Wikipedia article on combines -- http://en.wikipedia.org/wiki/Combine_harvester

1949 Popular Mechanics magazine with cutaway picture of a self-propelled combine of its era, plus pictures of two small miniature reapers at work on extension experimental farms. http://tinyurl.com/3k3func

1937 picture of a self-propelled cutting header, Australia http://museumvictoria.com.au/sunshine/displayimage.asp?iid=13350

More early designed, 1885 to 1930s, from Australia http://museumvictoria.com.au/sunshine/displaysubtheme.asp?stid=4&tid=2

Pictures of threshers, northern Great Plains of the US, 1890s through 1940s. http://memory.loc.gov/ammem/award97/ndfahtml/ngpSubjects21.html

Article about the development of the McCormick reaper. http://www.wisconsinhistory.org/wmh/pdf/wmh_spring01_grady.pdf

The Rodale thresher (stationary) http://www.cd3wd.com/cd3wd_40/JF/JF_OTHER/SMALL/Rodale%20grain%20thresher%20-%201977.pdf

Collection of third world implements, document #37 is a pedal powered thresher http://www.cd3wd.com/cd3wd_40/JF/JF_VE/BIG/06-232.pdf

1979 book on the design and building of a pedal thresher. Includes 21 drawings. http://www.cd3wd.com/cd3wd_40/CD3WD/APPRTECH/THRESHER/EN/INDEX.HTM 

.

Combine - Specific

Combine - Background Debriefing

Combine - Information Work

Combine - Hardware Work

Combine - Articles

Micro Combines

For small scale agriculture, harvesting can be done with micro combines. Micro combines can be broken down into two categories: towed and self propelled. Towed combines are hard to find due to them being out of production since the ‘60s in the U.S. However, demand for them is growing with small scale farmers. The old Allis Chalmers model 60 combines were widely used in America as one of the main combines used for grain harvesting. They can be pulled behind a tractor, and are PTO driven. Some companies have started buying these combines, refurbishing them, and reselling them to farmers. Self propelled combines are the types currently being developed. Operators of these machines either ride them or must walk behind them as they harvest. These self propelled units are beginning to see more use in rice harvesting in Asian countries. The combines in the following list are all self propelled with the exception of the Shenmao Harvester, which is hand held.

Briggs & Stratton Model Picture taken from: http://www.hcmuaf.edu.vn/ctt/softs/pkh/tailieu/tapchi_khkt/2004/TC%20-%204%20-%2004/PHHien.pdf Working width: 1.2 m Working Speed: 1.5 – 2.1 km/hr Idle travel speed: 2.0 – 5.0 km/hr Field capacity: 1 ha/day Cutting height: 0.1 – 0.4 m Combined losses: <2.0 % Engine power: 16 Hp Fuel consumption: 15 L/ha Labor requirement: 5 workers Overall dimensions: 3.5m X 1.5m X 1.5m Net weight: 600 kg

Mitsubishi 502 Rice Harvester Pictures taken from: http://www.ferrari-tractors.com/PDF%20Articles/Micro%20Grain%20Combine%20August%202009.pdf

Head width: 25” Field capacity: 1 acre/9 hrs Unit cost: $25,000 Wheel type: Crawler tracks

Cicoria Combine Picture taken from: http://www.ferrari-tractors.com/pictures/ss11.htm

Head width: 78” Overall dimensions: 192” X 92” Unit weight: 5,390 lbs Head type: General crop header with axial threshing drum Engine power: 38 Hp

Shenmao Harvester Picture taken from: http://shenmao.en.alibaba.com/product/250305412-209425313/43cc_small_Grain_Harvester.html

Engine size: 43cc 2-stroke Unit weight: 7.5 kg No other information could be found, so it is unclear how well it actually works

Agriculture in developing countries is largely done on many small scale plots, and there is a need for small scale harvesters to help increase crop production. There are already several companies producing micro combines and harvesters, but there is still a need for cheaper and more efficient machines. Continued development of micro combines will help make small scale farmers better able to make a living, and make their lives easier.

Works Cited

Canales, E. 1999. Small Scale Grain Production Today. Gridley, CA.: Ferrari Tractors. Available at: http://www.ferrari-tractors.com/smallscale.htm. Accessed 23 January 2010.

Hien, P. H., and L. Van Ban. 2004, The Mini Combine-Harvester: Research Results and a Related Automation Concept. Journal of Agricultural Sciences and Technology. 4: 95-100.

Micro Grain Combine. Gridley, CA.: Ferrari Tractors. Available at: http://www.ferrari-tractors.com/PDF%20Articles/Micro%20Grain%20Combine%20August%202009.pdf . Accessed 25 March 2010.

Zhejiang Shenmao Appliance Co., Ltd. Available at: http://shenmao.en.alibaba.com/product/250305412-209425313/43cc_small_Grain_Harvester.html . Accessed 25 March 2010.


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