8 Common Mistakes When Choosing a Excavator Long Arm

In the heavy machinery sector, especially when it comes to excavators, long arms—or extended booms—are often seen as a solution for deeper trenches, wider ditches, riverbank work, and broader radius operations. At Dewanda, where we manufacture and customize long arms for clients across diverse working environments, we’ve noticed that many customers make costly decisions by misunderstanding key factors.

A long arm is not a one-size-fits-all upgrade. It changes your excavator’s dynamics, structural stress points, weight distribution, and hydraulic behavior. The wrong choice can reduce efficiency, increase fuel consumption, shorten component life, or in worst cases, create serious safety hazards.

Below we outline eight common mistakes that contractors and equipment buyers often make when selecting a long arm—and the professional guidance to avoid them.

Mistake 1: Assuming Longer Is Always Better

Issue: Many buyers believe that the longest arm will automatically give them the most productivity. In reality, longer arms reduce breakout force, increase cycle time, and amplify tipping risk, especially if the excavator’s counterweight and undercarriage are not adjusted accordingly.

Dewanda Tip: Choose the arm length that balances reach with force. For example, for a 20-ton excavator working on a drainage canal, a 6.5 to 7.5 meter long arm might be ideal—but going beyond 8 meters without additional counterweight invites risk.

Mistake 2: Ignoring the Role of Counterweight

Issue: An extended arm shifts the machine’s center of gravity forward. Without adequate counterweight, the excavator becomes unstable, especially during full extension or when carrying heavy buckets.

Dewanda Tip: Always check the manufacturer’s counterweight recommendation or consult your arm supplier. Dewanda provides counterweight range charts for each custom arm. In some cases, we engineer bolt-on plates or suggest factory-standard upgrades.

Mistake 3: Overlooking Attachment Compatibility

Issue: Not all attachments are suitable for long arm setups. Hydraulic thumbs, ripper teeth, heavy-duty grapples, or hammers may overload the structure or compromise swing stability.

Dewanda Tip: When ordering a long arm, specify the exact attachments to be used. Our engineers will analyze the torsional and vertical stress caused by the tool and reinforce welds or advise alternate configurations.

Mistake 4: Using Standard Cylinders on Extended Arms

Issue: Standard boom or stick cylinders may not be rated for the hydraulic load produced by a longer lever arm. The result is slower movement, reduced lifting power, or cylinder seal failure.

Dewanda Tip: For every arm beyond 1.5 meters longer than OEM size, Dewanda recommends checking cylinder stroke, diameter, and pressure ratings. We offer hydraulic cylinder upgrades with extended stroke limits and heavy-duty rods.

Mistake 5: Neglecting Transport and Storage Requirements

Issue: A long arm often exceeds legal transport dimensions. Contractors are sometimes surprised when their new excavator cannot be transported on a standard flatbed without removing the arm.

Dewanda Tip: Plan logistics before ordering. Dewanda offers sectional or bolt-on arms for easy disassembly. We can also help you calculate transport height, turning radius, and storage layout.

Mistake 6: Failing to Consider Ground Pressure and Track Width

Issue: The additional arm weight increases the excavator’s ground pressure, which may cause sinking or instability on soft or uneven terrain. A narrow track frame exacerbates this risk.

Dewanda Tip: For long arm applications, especially in wetlands or riverbanks, we recommend wide-gauge tracks or track widening kits. Always analyze the ground bearing capacity before operating.

Mistake 7: Choosing Based on Price Instead of Purpose

Issue: Many buyers select a long arm supplier based purely on the lowest quote, assuming all arms are built equal. Poor-quality arms may use substandard welding, inferior steel, or incorrect geometry.

Dewanda Tip: Always request the steel grade, weld method (manual or robotic), and internal ribbing design. Dewanda provides full design diagrams and stress point analysis to ensure the arm matches the real demands of your job site.

Mistake 8: Ignoring Maintenance Access and Lubrication

Issue: Some long arms are difficult to service due to inaccessible grease points or non-standard bushings. Over time, this leads to accelerated wear and joint failure.

Dewanda Tip: Our long arms come with accessible grease ports, standard bushing sets, and optional centralized lubrication systems. Always inspect how easy it is to maintain the arm before purchasing.

Precision Matters

Long arm customization is not a catalog process. At Dewanda, each arm is designed based on application type—whether you’re trenching, dredging, or slope-grading. We guide you from design consultation to on-site use, ensuring your excavator delivers stability, performance, and safety.

If you’d like a Chinese translation, product sheet version, or CAD drawing support for your long arm planning, contact us!