As you can see, the pricing varies widely and is inconsistent. This inconsistency is due to several factors, including the obvious issues of age and condition, but also because the market is not large enough to establish any consistency.

Sources for used systems
Systems are available through various sources, including used-equipment dealers, internet auctions, consignment services and individual business-to-business sales.

Evaluating used electro-mechanical test systems
By definition, “electro-mechanical” is the term usually associated with the traditional tensile tester or universal test machine (UTM). Although electro-mechanical systems are technically simple, they can be complicated to upgrade because of the wide range of mechanical designs and motors used.

Mechanical evaluation of a used electro-mechanical machine should include wear on the ball screws, gears, belts, bearings and other mechanical components. You can do this by having a service engineer from a reputable supplier inspect the machine or by getting data on the machine’s usage and service records.

Because most of the used systems now on the market were sold with older computer or manual electronics, new controller upgrades often involve upgrading the full controller, motors, computer and software. You can usually get complete upgrades from the original manufacturer or from third party rebuilders.

To summarize, if you find a used electro-mechanical system in good mechanical condition, contact the original supplier or a reputable third party rebuilder to get a thorough understanding of the controller upgrade costs before deciding on a purchase price.

Evaluating used servo-hydraulic test systems
Servo-hydraulic test systems are based on hydraulic actuators and valves, using the motion of the actuator to run static or dynamic tests. These systems are often referred to as “fatigue test systems” or “MTS Systems.”

Evaluation of the hydraulic components should include inspection of the actuator. Signs that the actuator may need to be rebuilt include oil leakage around the seals and score lines on the actuator piston rod. Rebuilding the actuator and adding a new or refurbished servo valve will make the core element of these systems virtually brand new.

The other key component of a servo-hydraulic system is the hydraulic power supply. These units have hour meters and can also be evaluated by analysis of the hydraulic oil. Also consider the condition of the displacement linear variable differential transformer, test fixtures (grips), extensometers, hoses and cables.

Servo-hydraulic systems are all based on a somewhat standardized servo-valve control, so no matter what model or brand you have, there’s usually a straightforward upgrade option. If the system has a computer-based controller and is over 10 years old, then the solution is to upgrade to a complete new control system. Many older servo-hydraulic systems based on analog controls, such as the MTS 458, may not need any upgrade provided this control technology meets your needs.

In summary, if you find a used servo-hydraulic system in almost any condition, contact the original supplier or reputable third party to get a thorough understanding of any rebuild costs, and the controller upgrade costs, before determining a purchase price.

Comparisons of new and used system costs
As a general rule, a used system may be considered a good value if after paying for the initial cost and upgrade costs the total is no more than 60 percent of a new system. At this price level you have a system that’s updated to current technology but is still used and may still have service or other hidden unknown repair costs.

Now let’s consider the cost of used vs. new servo-hydraulic systems. In this scenario, a lab manager purchases a used servo-hydraulic test frame for about half the price of a new frame or about $11,000. Assuming the actuator needs to be rebuilt and the controller needs to be upgraded, Table 2 will illustrate the costs comparison. The calculations are based on a total cost approach analysis using the net present value of money and assuming a 10 percent cost of capital.

As shown in this table, the new system cost is only about $11,000 more. Although all these costs may not be incurred at first, it’s safe to assume that sometime within 1–5 years these components would require upgrading at additional cost.

There are some exceptional values in the market if you get lucky, but this analysis is based on typical scenarios. One recent customer was able to purchase a complete used table-top servo hydraulic test system for $5,000 plus shipping costs. After installation, calibration and a minor controller upgrade, the total initial investment was approximately $30,000 for a system that would have been about $70,000 new.

The depreciation tax advantage
The depreciation of test systems is another factor to consider when you’re determining the real costs of purchasing new or used test equipment. Material test systems fall into a 5-year depreciation schedule based on IRS rules. Table 3 outlines the depreciation calculations for a typical $90,000 test system.

The results of this calculation show that the depreciation schedule for new test systems provides a significant tax savings and real reduction of the actual cost in net-present-value of approximately $23,000.

Conclusions
When considering used test equipment, beware. Keep in mind that there’s no consistency in used test-system pricing and there may be hidden repair costs.

Although new test systems will typically cost a little more, the difference is relatively small if you consider all the advantages of a new material-test system including:

• Better selection of options and accessories
• The latest controller technology
• Full system warranty and technical support
• Lower maintenance costs