{"id":694,"date":"2026-05-27T07:20:57","date_gmt":"2026-05-27T07:20:57","guid":{"rendered":"https:\/\/rock-crusher-tractor.com\/?p=694"},"modified":"2026-05-27T07:20:57","modified_gmt":"2026-05-27T07:20:57","slug":"ep-ew-4000-rock-rake-complete-guide-korea-2","status":"publish","type":"post","link":"https:\/\/rock-crusher-tractor.com\/id\/ep-ew-4000-rock-rake-complete-guide-korea-2\/","title":{"rendered":"EP-EW-4000 Rock Rake \u2014 Panduan Lengkap untuk Mesin Pengumpul Batu Permukaan yang Paling Banyak Digunakan di Korea"},"content":{"rendered":"
\n

<\/p>\n

\n
<\/div>\n
\n

EP-EW-4000 Rock Rake \u2014 Complete Operation Guide for Korean Highland and Agricultural Farms<\/h1>\n

The EP-EW-4000 is the right tool when stone density does not require the THOR 2.4 \u2014 and knowing that threshold precisely is what makes Korean highland stone management economical rather than expensive. Most farms over-deploy the stone crusher on tasks the rake handles just as well at a fraction of the operating cost.<\/p>\n

Rock Rake Availability and Configuration<\/a><\/p>\n<\/div>\n<\/div>\n

<\/p>\n

Itu Penggaruk batu EP-EW-4000<\/a> is the highest-utilisation machine in the Korean highland stone management system \u2014 more Korean highland farms use the EP-EW-4000 for more hours per year than any other stone management machine in the Watanabe product range. Its 75 HP tractor requirement places it within reach of standard Korean domestic farm tractors; its 3.6 m working width delivers efficient coverage on agricultural field scales; and its surface collection capability addresses the most common Korean highland stone management task \u2014 annual frost-heave surface stone removal from established fields \u2014 more efficiently than any alternative approach.<\/p>\n

Understanding how to use the EP-EW-4000 correctly requires understanding what it is designed to do and, equally important, what it is not designed to do. The EP-EW-4000 is a surface stone collection machine. It does not crush, does not penetrate the soil profile, and cannot address embedded stones below approximately 8\u201310 cm. Its effectiveness is absolute within those parameters \u2014 and its deployment on tasks outside those parameters produces inadequate results that lead operators to incorrectly conclude the machine is insufficient when in reality the task required the THOR 2.4 stone crusher instead.<\/p>\n

<\/p>\n

EP-EW-4000 Confirmed Specifications<\/h2>\n

\"CT-2100<\/p>\n

Semua spesifikasi diambil dari brosur produk resmi Watanabe.<\/p>\n

\n
\n
75 HP<\/span><\/div>\n
Traktor minimum<\/div>\n<\/div>\n
\n
3.6 M<\/span><\/div>\n
Lebar kerja<\/div>\n<\/div>\n
\n
Kategori 2<\/div>\n
Pengait tiga titik<\/div>\n<\/div>\n
\n
540 RPM<\/span><\/div>\n
Kecepatan PTO<\/div>\n<\/div>\n
\n
10\u201315 ha\/hari<\/span><\/div>\n
Typical coverage<\/div>\n<\/div>\n<\/div>\n

<\/p>\n

The Core Decision \u2014 EP-EW-4000 Rake or THOR 2.4 Crusher?<\/h2>\n

The most important stone management decision in Korean highland farming is made every spring after soil thaw: which machine does this field need this year? Getting this decision right saves significant operating cost in the majority of seasons where the rake is adequate, while ensuring the THOR is deployed in the minority of seasons where it is genuinely needed. The decision framework:<\/p>\n

\n\n\n\n\n\n\n\n\n\n
Field condition after spring thaw<\/th>\nEP-EW-4000<\/th>\nTHOR 2.4<\/a><\/th>\nDecision basis<\/th>\n<\/tr>\n<\/thead>\n
Surface stones all below 40 Kg, none above 15 cm<\/td>\n\u2705 Correct<\/td>\nOver-deployment<\/td>\nStandard light frost-heave year \u2014 rake handles the full stone population<\/td>\n<\/tr>\n
Occasional stones 40\u201380 Kg (below 25 cm)<\/td>\n\u26a0 Partial only<\/td>\n\u2705 Correct<\/td>\nRake windrowed small stones; THOR crushes the above-40Kg stones the rake cannot move<\/td>\n<\/tr>\n
Multiple stones above 40 Kg in each field section<\/td>\n\u274c Insufficient<\/td>\n\u2705 Correct<\/td>\nHeavy frost-heave or new land: THOR crushing required before rake collection is possible<\/td>\n<\/tr>\n
Post-THOR pass \u2014 crushed aggregate to collect<\/td>\nNot typically<\/td>\nAlready passed<\/td>\nCT-2100 picker handles post-THOR collection; EP-EW-4000 for supplementary windrow sweeping if needed<\/td>\n<\/tr>\n
Orchard, pasture, ginseng alley \u2014 surface only<\/td>\n\u2705 Ideal<\/td>\nUnnecessary power<\/td>\nLow stone density, shallow collection: rake is perfectly matched to these light-maintenance applications<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

<\/p>\n

How the EP-EW-4000 Works \u2014 Tine Drum, Windrow, and Collection<\/h2>\n

\"Korean<\/p>\n

The EP-EW-4000 uses a rotating tine drum \u2014 a series of spring-steel tines mounted on a horizontal drum driven by the tractor’s 540 RPM PTO. As the tractor moves forward, the rotating tines sweep the soil surface in the opposite direction to forward travel, dislodging surface stones and rolling them backward into a concentrated windrow behind the machine. The tines penetrate the soil surface to a depth of approximately 5\u201310 cm (operator-adjustable through the rear skid height setting), collecting stones from this upper collection zone while leaving the soil largely undisturbed below the tine penetration depth.<\/p>\n

\n
\n

\u21b3 Tine penetration depth<\/span><\/p>\n

Set by the rear skid height \u2014 lower skid = deeper tine penetration = more soil disturbance but better small stone collection. Raise skids on road surfaces and established turf to prevent unnecessary surface disruption. Target: tines should just penetrate the soil crust without forming visible furrows in firm soil.<\/p>\n<\/div>\n

\n

\u21b3 Windrow position<\/span><\/p>\n

The EP-EW-4000 deposits its collected stone windrow behind the machine on the centreline of the working pass. Subsequent passes are planned so that the CT-2100 collection vehicle can follow in the windrow line \u2014 aligning pass direction with the CT-2100’s optimum collection trajectory for maximum pick-up efficiency.<\/p>\n<\/div>\n

\n

\u21b3 Maximum stone size<\/span><\/p>\n

The EP-EW-4000 tines effectively collect stones up to approximately 40 Kg per stone. Stones above this size cannot be displaced by the tine rotational force \u2014 they stop the tine drum momentarily or are rolled sideways. Encountering multiple above-40 Kg stones in a field section during the rake assessment is the trigger for THOR deployment on that section.<\/p>\n<\/div>\n<\/div>\n

<\/p>\n

Operating Setup \u2014 Speed, Skid Height, and Pass Planning<\/h2>\n

\"Korean<\/p>\n

Three variables control EP-EW-4000 performance: forward speed, skid height (tine penetration depth), and pass-line planning. Correct setup for each application type:<\/p>\n

\n
\n

Agricultural field \u2014 standard setup<\/p>\n

Speed:<\/strong> 4\u20136 km\/h. Lower end (4 km\/h) maximises small-stone collection completeness on fine-stone passes. Upper end (6 km\/h) for efficient wide-area coverage when stone density is low and completeness of very small stones is less critical.<\/p>\n

Skid height:<\/strong> Set so tines just touch the soil surface crust without forming visible grooves on firm, slightly moist spring soil. Adjust at the first 20 m test pass \u2014 look back at the windrow profile and the surface behind the tines.<\/p>\n<\/div>\n

\n

Orchard alley \u2014 narrow width setup<\/p>\n

Speed:<\/strong> 4\u20135 km\/h \u2014 orchard tractors typically operate more slowly than field tractors; confirm tractor forward speed matches the 540 RPM PTO engagement without excessive drum speed.<\/p>\n

Skid height:<\/strong> Raise slightly above field setting \u2014 orchard alley turf or ground cover should not be disturbed unnecessarily. Rake should collect surface stones without leaving bare soil strips in the orchard alley.<\/p>\n<\/div>\n

\n

Post-THOR supplementary sweep<\/p>\n

Speed:<\/strong> 5\u20136 km\/h \u2014 post-THOR stones are already fragmented and at the surface. The rake pass concentrates them into windrows for CT-2100 collection more efficiently than CT-2100 direct collection from scattered surface distribution.<\/p>\n

Skid height:<\/strong> Standard field setting. THOR-crushed soil is already loosened \u2014 tines penetrate easily to the collection depth without special adjustment.<\/p>\n<\/div>\n<\/div>\n

<\/p>\n

Orchard, Ginseng Alley, and Legume Year Applications<\/h2>\n

\"Highland<\/p>\n

The EP-EW-4000’s 75 HP requirement and relatively gentle surface action (no crushing, no soil inversion) make it the standard choice for a wide range of Korean agricultural applications where the THOR 2.4’s 180 HP power and stone crushing action is either unavailable or unnecessary:<\/p>\n

\n
\n

Korean apple, pear, and persimmon orchards<\/p>\n

Highland orchard alleys accumulate frost-heave surface stones annually in the same granitic soils as field crops. The EP-EW-4000’s 3.6 m working width is typically wider than a standard orchard alley (2.5\u20133.5 m) \u2014 requiring offset passes. Tine height set to preserve ground cover turf. The CT-2100<\/a> collection follows in the windrow line. Annual orchard alley clearance in March prevents tyre punctures from harvest equipment during the August\u2013November orchard harvest period.<\/p>\n<\/div>\n

\n

Ginseng field alleys (during 6-year cultivation)<\/p>\n

As described in the ginseng stone clearing guide, the EP-EW-4000’s annual role during the ginseng growing cycle is alley maintenance \u2014 not bed stone clearance. The 60\u201380 cm alley width requires narrow-width operation: one tractor wheel in each alley, EP-EW-4000 overhanging slightly into adjacent alleys on either side. Some Gangwon-do ginseng farmers use narrower specialty rakes for ginseng alley work \u2014 confirm with Korea Watanabe whether EP-EW-4000 width is compatible with your specific ginseng bed geometry before deployment.<\/p>\n<\/div>\n

\n

Legume year in the 4-crop rotation<\/p>\n

The legume year (Year 4 in the potato\u2013radish\u2013cabbage\u2013legume rotation) has minimal stone management requirements. Annual frost-heave is the only stone emergence mechanism on established fields. The EP-EW-4000 handles this light annual maintenance in the legume year \u2014 the THOR 2.4 is not needed and should not be deployed on fully established, light-stone legume fields. This correct machine selection during the legume year reduces the THOR 2.4’s annual operating hours and tooth consumption by approximately 20\u201325% on a 4-block rotation farm, extending the THOR’s maintenance intervals and reducing annual operating cost.<\/p>\n<\/div>\n<\/div>\n

<\/p>\n

EP-EW-4000 Annual Maintenance \u2014 Simple but Essential<\/h2>\n

The EP-EW-4000’s maintenance requirements are significantly less demanding than the THOR 2.4’s \u2014 its mechanical simplicity (tine drum, PTO driveline, skid adjustment) means fewer wear items and shorter service intervals. However, deferred maintenance on the tine drum bearing and tine replacement produces a noticeable performance decline that operators often attribute to “field conditions” rather than machine wear:<\/p>\n

\n\n\n\n\n\n\n\n\n
Selang<\/th>\nTugas<\/th>\nSymptom if neglected<\/th>\n<\/tr>\n<\/thead>\n
Before each season (Feb)<\/td>\nInspect all tines \u2014 replace bent, shortened (below 70% of new length), or cracked tines; grease tine drum bearings; check PTO shaft joints; confirm skid height adjustment mechanism free<\/td>\nBent tines miss stones and reduce windrow quality; worn tines reduce collection completeness on smaller stones<\/td>\n<\/tr>\n
Setiap 8 jam operasional<\/td>\nGrease tine drum end bearings; check for any tine fracture after heavy stone contact; confirm PTO shaft shielding intact<\/td>\nDry tine drum bearings squeal under sustained rotation load \u2014 failure requires drum removal and bearing replacement<\/td>\n<\/tr>\n
Mid-season inspection<\/td>\nIf collection completeness has visibly declined: re-measure all tines and replace worn items; re-check skid height setting drift (skid bolts can loosen under vibration)<\/td>\nSkid height drift causes inconsistent tine penetration \u2014 varies from too shallow (missing small stones) to too deep (soil disturbance)<\/td>\n<\/tr>\n
Akhir musim<\/td>\nReplace all tines below replacement threshold; clean soil from tine drum and PTO shaft; grease all points before storage; protect PTO shaft joints from winter corrosion<\/td>\nMachine stored with borderline tines begins next spring at reduced performance \u2014 the low-cost, high-impact maintenance action<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

<\/p>\n

EP-EW-4000 in the Complete Korean Stone Management System<\/h2>\n

The EP-EW-4000 is not a standalone machine \u2014 it operates as part of the three-machine Korean highland stone management system alongside the THOR 2.4 stone crusher and the CT-2100 rock picker. Understanding how the three machines interact clarifies when each one is deployed and how their combined coverage achieves zero-residual stone standard across all field types and stone conditions:<\/p>\n

\n
\n

THOR 2.4<\/p>\n

Embedded and oversized stones above 40 Kg. New land, heavy frost-heave years. 180 HP. Full root-zone depth. Kit Drawbar for slope terrain.<\/p>\n<\/div>\n

\n

EP-EW-4000<\/p>\n

Surface stones below 40 Kg. Light frost-heave years. 75 HP. Orchard, ginseng alleys, legume year. Windrows for CT-2100 collection.<\/p>\n<\/div>\n

\n

CT-2100<\/p>\n

Collection in all scenarios. Follows THOR crushing or EP-EW-4000 windrows. 110 HP. 2.5 m\u00b3 bunker. Converts clearance into zero-residual result.<\/p>\n<\/div>\n<\/div>\n

The three-machine system’s total operating cost is dominated by the THOR 2.4 (highest HP, highest tooth wear cost). Correctly identifying the years and field sections where the EP-EW-4000 is sufficient \u2014 rather than defaulting to the THOR in all situations \u2014 is the management decision that keeps the system economical across the full Korean highland farming calendar. On a well-managed 10 ha highland farm running the 4-crop rotation, the EP-EW-4000 typically operates 30\u201340 hours\/year while the THOR 2.4 operates 15\u201325 hours\/year \u2014 the lighter machine covering more total hours at lower hourly cost, while the heavier machine is preserved for the tasks that genuinely require its capability.<\/p>\n

<\/p>\n

Pertanyaan yang Sering Diajukan<\/h2>\n
\n
\nHow do I know if a stone is above or below the 40 Kg threshold in the field?<\/summary>\n

A practical field method: a 40 Kg stone of Korean granite (density approximately 2,650 Kg\/m\u00b3) is approximately 15\u201318 cm in diameter in spherical equivalent. You can estimate this: a stone that a single person can pick up and carry is almost certainly below 40 Kg. A stone that requires two people to lift but can still be moved manually is approximately 40\u201380 Kg \u2014 borderline for the EP-EW-4000, and indicates THOR deployment for that section if multiple stones of this size are present. A stone that two people cannot move without mechanical assistance is above 80 Kg and requires THOR 2.4 crushing. During the spring walk, systematically note how many stones require two people to move \u2014 if more than 3\u20135 per 100 m\u00b2 of field area, deploy the THOR on that section. If all stones can be moved by one person, the EP-EW-4000 is the correct machine.<\/p>\n<\/details>\n

\nCan the EP-EW-4000 work on wet Korean highland spring soil without damaging soil structure?<\/summary>\n

The EP-EW-4000 is less damaging to soil structure on wet soil than the PSW-3200 rotavator because its tines do not invert or smear the soil \u2014 they simply sweep the surface and collect stones. However, operating the EP-EW-4000 on very wet, plastic soil (where the soil surface deforms visibly under tractor weight) does cause tractor wheel compaction in the wheel tracks. This wheel-track compaction is unavoidable in wet conditions regardless of which machine is used. The recommendation: wait until the soil surface can support tractor weight without visible deformation (roughly 3\u20135 days after heavy rainfall on typical Korean highland granite soils) before commencing EP-EW-4000 operations. The tine drum itself has minimal soil compaction effect at the surface \u2014 the compaction risk is from tractor wheel loading, not from the rake mechanism.<\/p>\n<\/details>\n

\nWhat is the annual tine replacement cost for the EP-EW-4000?<\/summary>\n

The EP-EW-4000 tine replacement frequency on Korean highland granite soil depends on annual operating hours and stone hardness. Typical tine life is 60\u2013120 operating hours before tines reach the 70% replacement threshold. On a 10 ha farm running 30\u201340 hours\/year, tine replacement is typically needed every 2\u20133 seasons \u2014 some tines replacing annually (those that contact harder stone concentrations) and others lasting 3\u20134 seasons. Korea Watanabe holds EP-EW-4000 tine replacement sets in Korean local stock. Contact Korea Watanabe for current tine set pricing and lead time confirmation \u2014 order tine replacements in January as part of the standard pre-season service preparation alongside THOR tooth sets and PSW-3200 blade sets to consolidate parts ordering into a single annual procurement.<\/p>\n<\/details>\n

\nIs the EP-EW-4000 eligible for Korean agricultural machinery subsidies?<\/summary>\n

Yes \u2014 the EP-EW-4000 qualifies under the Korean agricultural machinery purchase support program in the farmland improvement machinery category, the same category as the THOR 2.4 and CT-2100. Korea Watanabe holds the Korean agricultural machinery certification for the EP-EW-4000 and provides full subsidy documentation at no charge. For farms purchasing multiple stone management machines (EP-EW-4000 + CT-2100 + THOR 2.4), all three can be included in a single annual subsidy application \u2014 subject to the per-farmer annual subsidy cap. Korea Watanabe advises on structuring multi-machine applications to maximise subsidy access across the full system in a single or phased application.<\/p>\n<\/details>\n

\nHow many passes does the EP-EW-4000 need to achieve a clean field on a 5 ha highland vegetable plot?<\/summary>\n

On an established highland field with light-to-moderate frost-heave, the EP-EW-4000 achieves commercially adequate surface clearance in one pass per row spacing aligned with the subsequent CT-2100 collection lines. A single rake pass at 4\u20135 km\/h across 5 ha (at 3.6 m working width = approximately 14 passes across the field width + headland turns) takes approximately 2\u20133 hours of effective machine time \u2014 typically half a morning. The CT-2100 collection following the rake windrows takes a similar time, giving a complete 5 ha EP-EW-4000 + CT-2100 annual clearance operation in a single working day. Compare this to the same 5 ha with THOR 2.4 + CT-2100 (180 HP machine, deeper penetration, lower forward speed): approximately 1.5\u20132 full working days. The EP-EW-4000’s time and cost efficiency advantage on light-stone established fields is the core reason for having both machines in the Korean highland system.<\/p>\n<\/details>\n<\/div>\n

<\/p>\n

\n

EP-EW-4000 Configuration and Stock Confirmation<\/p>\n

Farm type (highland vegetable \/ orchard \/ ginseng) + area (ha) + annual stone history \u2192 EP-EW-4000 alone or EP-EW-4000 + THOR 2.4 recommendation with subsidy documentation preparation. Korea Watanabe, Ansan-si, Gyeonggi-do.<\/p>\n

Hubungi Kami Sekarang<\/a><\/p>\n<\/div>\n

Editor: Cxm<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"

EP-EW-4000 Rock Rake \u2014 Complete Operation Guide for Korean Highland and Agricultural Farms The EP-EW-4000 is the right tool when stone density does not require the THOR 2.4 \u2014 and knowing that threshold precisely is what makes Korean highland stone management economical rather than expensive. Most farms over-deploy the stone crusher on tasks the rake […]<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"categories":[31],"tags":[],"class_list":["post-694","post","type-post","status-publish","format-standard","hentry","category-application-and-technical-guid"],"_links":{"self":[{"href":"https:\/\/rock-crusher-tractor.com\/id\/wp-json\/wp\/v2\/posts\/694","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rock-crusher-tractor.com\/id\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rock-crusher-tractor.com\/id\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rock-crusher-tractor.com\/id\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/rock-crusher-tractor.com\/id\/wp-json\/wp\/v2\/comments?post=694"}],"version-history":[{"count":3,"href":"https:\/\/rock-crusher-tractor.com\/id\/wp-json\/wp\/v2\/posts\/694\/revisions"}],"predecessor-version":[{"id":700,"href":"https:\/\/rock-crusher-tractor.com\/id\/wp-json\/wp\/v2\/posts\/694\/revisions\/700"}],"wp:attachment":[{"href":"https:\/\/rock-crusher-tractor.com\/id\/wp-json\/wp\/v2\/media?parent=694"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rock-crusher-tractor.com\/id\/wp-json\/wp\/v2\/categories?post=694"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rock-crusher-tractor.com\/id\/wp-json\/wp\/v2\/tags?post=694"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}