Dura-Belt		800-770-2358		WHERE TO BUY

Eagle XLD O-ring Belt Review

Fenner's new Eagle XLD O-ring belt sounded like a game changer, but the following tests show that most of their claims are not valid and that their belt can damage Motorized Drive Rollers (MDR).

XLD O-ring Belt Comparison

This test was performed on a 24VDC MDR conveyor, running continuously with no load after 3 days run-in.

Meter reading	XLD O-ring Belt (reinforced with Kevlar)	V-Conform Belt (reinforced with stretchy nylon)	HT Blue belt (unreinforced polyurethane)	Number of Rollers in Zone
LOWEST Speed (ft/min)	115	115	115	10
Peak DC Amps*	4.33	2.33	1.55	10
Average DC Amps*	1.75	0.91	0.61	10
MDR temperature (hand gripped the motor area)	Hot	Warm	Warm	10
----------	----------	----------	----------	----------
HIGHEST Speed (ft/min)	179	201	201	10
Peak DC Amps*	5.45	3.78	2.30	10
Average DC Amps*	2.10	1.36	0.93	10
MDR temperature (hand gripped the motor area)	Too Hot to hold	Hot	Warm	10
----------	----------	----------	----------	----------
HIGHEST Speed (ft/min)	158**	186**	201	15
Peak DC Amps*	7.26	4.07	2.85	15
Average DC Amps*	3.56	1.83	1.14	15
MDR temperature (hand gripped the motor area)	Overheated shut down after 1 hour	Hot	Warm	15

** Should be 200 ft/min. Needs larger power supply. 600 watts is not adequate to run 15 rollers at high speed.

Saves Energy? Fenner's ads claim their new XLD O-ring belts save energy, yet this test shows that at low speed their belts use almost twice as much energy as our V-Conform belts and nearly three times as much energy as our HT Blue polyurethane belts. At highest speed it runs too hot to hold, over stressing the MDR with no load on the conveyor! When powering a 15 roller zone at highest speed, it overheats and shuts down the MDR, reducing its lifespan.

No Stretch Belt? Fenner touts this as an advantage, but they don't seem to understand that idler rollers are not precision rollers. Instead, they often WOBBLE a little due to being slightly elliptical and/or slightly bowed and/or have shafts slightly off center. Moreover, belt grooves can vary slightly in depth even on the same roller. This off-center wobble means rollers act like small cams forcing no-stretch belts to put significant strain on motors with every roller rotation. Such "cam shock" causes motors to draw excessive current, close to the maximum current allowed, so they have little room to move heavier loads, faster and on longer zones. Poly-v belts on precision poly-v endcaps do not have such huge "cam-shock" problems because they run on precision grooves on perfectly round endcaps, and they are located on the end of the roller where bowed roller tubes have little effect.

Frayed XLD O-ring

Longer belt life? Fenner's so-called "D" belts are really "T-top half-round" belts. Their little T-top wings conform to fillets on groove edges. They work well on idlers that have wide grooves, but apparently they were not tested on MDR's narrow groves, where some of their edges are pressed upward and stick slightly above the roller's surface. This can cause box rotation and fray T-tops. XLD belts can also fray on 6° curves after running only 160 hours.

XLD's T-top may protrude above MDR's surface

6 times longer life? Polyurethane round belt's lifespan can vary widely, depending upon how they are used or abused. In a real world test in an ideal temperature and humidity controlled environment with precision rollers (TIR 0.015"), nearly all 40,000 HT Blue belts lasted 9 years in a USPS distribution center, so without actual real world tests, claiming the XLD belts will last 6 times longer is a stretch. However. the problem for no-stretch belts is not the belt's lifespan, but rather the MDR's lifespan. XLD no-stretch belts hammer MDRs and roller bearings with every rotation. You can see the hammering on an oscilloscope (see high resolution graph at bottom of this page) and feel how much hotter the MDR is. Years ago, such hammering also caused minimal-stretch Gygaprene belts to be discontinued because they adversely affected MDR lifespan. Conversely, 32 years of experience prove that our elastic polyurethane belts easily stretch and absorb "cam shock", thereby protecting motors and bearings.

Current Surges

Reduces System Costs? XLD belts cost three times more than the polyurethane belts they replace. The "cam" effects means they will probably reduce MDR and bearing lifespans so they will have to be replaced more often. XLD belts also operate so close to MDR/PLC maximum current ratings that any kind of jam can cause them to overheat and trigger thermistors that have limited lifespams. When the thermistor inside the MDR dies, it cannot be repaired so that kills the MDR -- an expensive loss. The extra energy needed to drive no-stretch XLD belts boosts the rate of energy needed to increase load, speed or zone length, as is shown by the steeper slope as in adjacent graph. All these problems greatly limit potential saving, so system costs will likely be significantly higher.

Eliminates Some MDRs? The adjacent graph shows that XLD's current usage is so high, even when operating at the MDR's lowest speed (115 ft/min), that the MDR can only move about 14 rollers without exceeding the maximum current rating. When running 15 rollers at high speed, it overheats and shuts down the MDR. In other words, XLD belts, running continuously, cannot eliminate even one MDR. This also means that they do not have much capacity to move heavier boxes at high speeds.

MDR Current vs Rollers

Eagle XLD O-rings with Finger Guards
that must be 4.5" (115mm) long

Drop in Replacement for urethane belts? This is true only in areas where human access is prohibited or not possible (like deep inside a diverter). Finger Guards are required by OSHA in areas where people can inadvertently put a finger under a belt that has a pinch point that can damage fingers. Fenner knows this but continues to run many "Drop in Replacement" ads that imply finger guards are not required. They need to run their ads past Michelin's legal department because failing to adequately warn about a known danger is gross negligence, subject to triple damage law suits.

Easy Installation? Center distances of holes between rollers have tolerances, typically +/-.010". On our test conveyor, the 3" center distances mean rollers are typically 2.99", 3.00" and 3.01" apart. Using the rollers as levers, installing belts on the first two center distances was fairly easy, although it required some effort to tension belts the last 1/16". However, one person could do it. Since XLD belts do not stretch, the 3.01" center distance took two employees to install the belts -- one person had to use both hands to pull the roller in place, while the other person guided the shaft into the hole.

Unfortunately, in areas where finger guards are required, installing the belts on rollers is only half the task. The other half requires installation of extra long 4.5" (115mm) finger guards, which can take much longer, especially if it involves drilling holes in the frame. Once finger guards have been installed, it is virtually impossible to install or remove belts without first removing the finger guards. Conclusion: installation of XLD belts where humans work is difficult, labor intensive and expensive.

Larger Power Supply Required. : Running with XLD O-rings at top speed on a 10 roller zone caused the MDR to be too hot to handle. The resulting reduction in top speed (see table above) means the MDR needs a larger power supply that would provide more amps and make it overheat more. On a 15 roller zone at top speed, XLD belts caused the MDR to thermally shut down. Running 2 seconds on and 1 second off would reduce the average current by 1/3, but the extra energy supplied by a larger power supply, when moving heavy loads, would likely raise the average current well over the maximum recommended 2.8 amps, damaging the MDR.

Super Sensitive to Roller Alignment. : We noticed that, if the roller grooves are slightly misaligned, the amps and temperature increases significantly and the speed decreases. That means that using XLD belts on skewed rollers, curves and/or longer zones may require still larger power supplies and further reduce MDR lifespan, while possibly overheating and warping plastic covered cartons, products and bags that pause above the hot MDR. Threaded shafts force grooves to be perfectly aligned, but spring loaded shafts usually have gaps between the roller and the frames. If the grooves are misaligned by 1/8" (3mm) on any two adjacent rollers, the current jumps 5% to 10% and the speed may decline.

Not green: XLD O-rings and V-Conform belts are not thermoplastic, so they are not biodegradable or recyclable like 97% or our polyurethane belts.

Bi-modulus Technology: This is a fancy way of saying reinforced, i.e., composed of two different materials. XLD belts appear to be made from polyurethane reinforced with no-stretch aramid (Kevlar) cord. For years other companies (Volta, Beha, TKF and Fenner) have sold bi-modulus round, vee and/or T-top half-round belts also reinforced with aramid or polyester, so "Bi-Modulus Technology" is nothing new. Incidentally, ConveyXonic Poly-V belts are quadra-modulus, i.e., 4 different materials. Bi-modulus and reinforced T-top half-round belts are prior art, so neither are patentable.

*Peak Amps = largest value in the range of 20 data points/second. These are frequently recurring amp spikes, not due to start up surges. Average Amps = average of 100 data points/0.5 second. The time graph is also plotted using the same average amps. MDR: Itoh Denki PM486FS-55-2. Driver card: CB016S7. Power supply: 600 DC watts at 24 volts.

This graph shows how XLD belts hammer MDRs with current spikes when moving at top speed on 15 roller zones. The spikes are visible at higher resolution (40,000 data points/second). They are not startup spikes. Rather, they repeat in microsecond pulses as cam forces move in and out of constructive reinforcement. This is what MDRs see, causing them to overheat and shut down.

XLD Current Surges at High Speed Cause MDR to Overheat and Shut Down

Special thanks for excellent technical help, priceless knowledge and conveyor parts furnished by QCON-24.

For the best in Reinforced O-ring conveyor belts, insist on DuraBelt.