Category: Blog

The core of the electric landing gear contains an eight-layer sensor array (detecting 0.01g vibration/0.1MPa pressure), a titanium alloy support structure (resisting 200MPa pressure), a planetary roller screw (contact area increased by 5 times) and a 32-bit MCU control system (2000 operations/second). The power module switches to the backup power supply in 3 milliseconds, and the buffer unloads the force by nitrogen pressure (the viscosity of the hydraulic oil in the first 70% of the stroke is ≤45cSt).

Drive motor

The motor of the electric outrigger of the truck is much more powerful than that of the RV. This thing has to withstand the brute force of a 30-ton heavy truck unloading its cargo with its body tilted, and it has to be as steady as an old dog in the mud. Now the mainstream is divided into two schools: brushed motors are cheap and durable, and brushless motors are precise and power-saving, just like the difference between manual and automatic transmissions.

The carbon brush of the brushed motor is a delicate bag. The mud and water mixture on the construction site can directly cut the life of the carbon brush in half. Last year, a fleet in Shandong replaced the inferior carbon brushes, and as a result, 8 of the 12 outriggers were burned during unloading. Experienced drivers all know that you have to use a motor with IP67 protection level, and the waterproof rubber ring should be as tight as a condom – don’t laugh, someone really did a comparative experiment with Durex.

The reduction box is the key to the burst of power. Although the efficiency of the worm gear structure is only 60%, the self-locking feature can save lives at critical moments. There is a counterintuitive design: after the outrigger is fully extended, the motor will rotate half a circle more, which is to offset the gap by pre-tightening the gear deformation. It’s like the last “click” sound when twisting the bottle cap. Without this design, the outrigger will shake like dancing.

Control system

The control system of the RV electric outrigger is much more pretentious than that of the truck. You have to take care of the millimeter-level leveling of the four outriggers at the same time, and you have to be careful of the slope of the camping site. Nowadays, high-end RVs all use dual control systems: the touch screen panel is used for show, and the physical buttons are kept for life. Last year, a popular RV changed the buttons to full touch control. As a result, the operation failed when wearing gloves in winter, and the owner almost flipped over on the snow slope.

The pressure sensor here plays permutations and combinations. The 16 sensors on the four legs will play “elimination” – automatically find the three most stable fulcrums, and the leg that is suspended is used for fine-tuning. This trick is learned from the tripod, but with a fool-proof design: if the ground is uneven, the system will reselect points like a hopscotch game.

The anti-overload mechanism is the real IQ tax disaster area. Don’t really push the 5-ton outriggers to 5 tons. Leaving 20% margin is an industry unwritten rule. A ruthless person found in actual testing that the protection mechanism of a certain brand of outriggers was activated at 4.8 tons, and it can actually carry another 1 ton – this is like an airbag, it is better to trigger it by mistake than to have an accident. Just like the overload protection of CNC machine tools, the set value is always 15% ahead of the nominal value.

Power module

The power heart of the electric landing gear is a schizophrenic. It must have continuous output like a power bank, but also have the awareness of explosion-proof devices. The mainstream now is the lithium battery + supercapacitor combination package, just like the off-road vehicle is equipped with double fuel tanks – lithium batteries are responsible for long-term flow, and capacitors are specialized in treating instantaneous large currents.

The battery management system is deeper than the ICU of a tertiary hospital. There are 48 temperature probes hidden in the 16-series and 24-parallel battery pack, which is denser than the thermometers in a hot pot restaurant. Last year, a copycat manufacturer cut corners and cut the number of probes in half, and as a result, the battery set off fireworks directly in the heat wave of Dubai Airport. The serious solution must use active balancing technology, just like equipping each battery unit with a private nutritionist.

Emergency power supply is the real black technology. After the main power supply is off, the supercapacitor can take over the power supply within 3 milliseconds-this speed is enough for you to blink one-tenth of your eyes. What’s even more amazing is the self-destruct fuse, which will melt into two pieces when it encounters a short circuit, just like a spy capsule.

Lifting mechanism

This mechanical system plays with the philosophy of combining rigidity and flexibility. The screw drive should be as precise as a Swiss Army knife, and the buffer device should learn to unload force like Tai Chi. Now high-end products all use planetary roller screws. Don’t be fooled by the mysterious name, it is actually turning the toothpick of the traditional screw into a mace – the contact area increases by 5 times, and the life span is directly doubled.

The self-locking mechanism is the life-saving trick. The electromagnetic brake must bite like a trap at the moment of power failure, and a delay of more than 10 milliseconds can cause a disaster. There is a counter-intuitive design: a greater driving force is required when descending, which is to prevent gravity acceleration from causing trouble. It’s the same as stepping on the brake when going down a steep slope, except that the motor is desperately rotating in the opposite direction.

Overload protection plays a psychological game. The nominal 10-ton landing gear can actually carry 15 tons, but the protection program will be activated if it exceeds 12 tons – this 20% margin is not due to poor technology, but a regret medicine for reckless people. Just like the feed force limit of CNC machine tools, it is obviously able to be tough, but it pretends to be weak. The ground staff of a certain airline company once tested a container as a counterweight, but after the protection was triggered, they thought the equipment was faulty, which made a big joke.

The voltage tolerance setting of the electric landing gear is comparable to walking on a tightrope. Lowering the threshold can protect the circuit but is easy to trigger by mistake, and raising it may burn components. Actual combat data shows that in the high salt fog environment in the coastal area, the voltage fluctuation threshold should be relaxed by 8%, and the thickness of the gold plating layer of the connector should be increased.

Sensor

This pile of electronic probes is the real “drama queen”. It is necessary to play the role of an honest man of the weighing sensor and take into account the gymnast attributes of the tilt sensor. Nowadays, high-end cargo planes are equipped with an eight-layer sensor array: 3 pressures + 2 angles + 1 vibration + 2 temperatures, which is three more than the five senses of the human body.

The vibration sensor plays a spy game. Use MEMS accelerometers to capture tiny vibrations of 0.01g. This sensitivity can detect the movement of the flight attendant pushing the food cart in the cabin. Last year, a cargo plane landed and the system alarmed. After disassembling it, it was found that two ball bearings inside the landing gear were broken – the vibration spectrum is more accurate than B-ultrasound.

Temperature compensation is the real black technology. Stainless steel will shorten by 0.2mm compared to normal temperature at minus 40℃, and the sensor must be able to do math problems by itself. Just like the thermal deformation compensation of five-axis machine tools, the landing gear sensor has a built-in material expansion coefficient database. The accident of the Antarctic expedition team was caused by a certain copycat sensor that misjudged the resistance change caused by low temperature as abnormal force.

Support structure

This pile of metal skeletons is playing a balancing act of “wanting both”. It has to be harder than Wolverine’s adamantium, but as soft as a cat’s paw. 7075-T6 aluminum alloy is the basic model, but the real tough ones use titanium alloy + carbon fiber woven layer – this configuration is comparable to the chassis of an F1 car, but the price can buy three BMW 7 Series.

The buffer is the magician of mechanics. The oil-gas mixed buffer must accurately control the CP value of nitrogen pressure and hydraulic oil viscosity, just like mixing a cocktail, you have to pay attention to the proportion. The unique skill of Boeing 787 is the two-stage buffer: the first 70% of the stroke is gentle like water, and the last 30% is suddenly hard-core, just like the experience of eating popping candy.

The joint connection is ten times more complicated than the human knee. The self-lubricating bearing must withstand a pressure of 200MPa, and it must also prevent sandstorms from playing Infernal Affairs. The most damaging design is the anti-misinstallation buckle – different diameter pins have exclusive torque codes. Want to install violently? No way! I learned this trick from the CNC tool handle. Back then, a ground crew used a sledgehammer to install the wrong part. Now, the buckle is more sophisticated than a bank vault lock.

The electric outrigger is driven by a DC motor. At low temperatures, the 2A preheating current ensures that it starts at -35℃. The pressure sensor detects that the hardness difference between cement and mud is 4 times. The speed difference of the four motors is ≤5% and they stretch synchronously. When encountering obstacles, the 5Hz vibration mode is activated. The vibration sensor warns of bearing failure 200 times in advance.

Signal reception

Last year, a refrigerated truck of a logistics company broke down in Heilongjiang at minus 25 degrees. The driver pressed the outrigger button three times but it didn’t respond. Later, it was found that the remote control battery had insufficient voltage at low temperatures. The signal reception of the electric outrigger of the truck is like an experienced driver stepping on the clutch, which requires the coordination of force and timing.

When the driver presses the control button, the signal must pass three levels before it can take effect. First, it must pass the heartbeat detection of the on-board CAN bus. This mechanism is exactly the same as the anti-mistouch design of the truck ECU. If the signal lasts less than 0.3 seconds, it will be filtered out directly. Then it must pass the voltage fluctuation test, especially the circuit interference problem often encountered by modified vehicles. Last year, there was a case where the wiring harness was improperly routed during the modification of the car audio, causing the outrigger signal to be swallowed by the radio electromagnetic wave.

The most terrible thing is signal conflict processing. For example, a common scenario in RVs: on one side, the outriggers are deployed with the remote control, and on the other side, the onboard computer automatic leveling system is also sending instructions. At this time, the arbitration chip in the control box has to direct traffic like a traffic policeman, and the priority level setting is particularly particular. Usually manual operation has the highest authority, but when the tilt sensor alarm is encountered, the safety command will automatically jump the queue.

There is a particularly interesting design detail – many new electric outriggers have two sets of signal decoding solutions hidden in the control box. Just like the “dual clutch backup” often said by truck drivers, one set handles conventional PWM pulse signals, and the other set is specifically for the switch signal of the old relay. Last year, I helped the modification factory solve a difficult problem: the outriggers of a European imported RV were incompatible with the domestic control system. In the end, it was found that the signal pulse width differed by 15 milliseconds, and it was solved by changing the resistance value.

System detection

A thrilling scene happened in a RV camp last year: when tourists deployed the outriggers, the four legs landed at different speeds, and almost threw the roof solar panel off. This detection system is like the eyes of an old repairman. It not only looks at the landing speed of the outriggers, but also listens to the working sound of the hydraulic pump.

Every time the outriggers are started, the system must complete five key checks. First, let the angle sensor confirm the vehicle’s inclination, which can reach an accuracy of 0.5 degrees, which is more accurate than the gyroscope on a mobile phone. Then the pressure sensor starts to work, sensing the hardness of the ground like a Chinese medicine pulse-the feedback pressure of cement and mud can differ by more than three times. The most intelligent is the speed synchronization detection. The speed difference of the four outrigger motors cannot exceed 5%, otherwise an emergency stop will be triggered immediately.

The handling strategy for encountering special terrain is particularly particular. For example, when the outriggers are deployed on a slope, the control system will automatically enter the “mountain climbing mode”. At this time, the outriggers on the uphill side will be extended by 20 mm, just like when people climb a mountain, they must step firmly on the front foot. Last year, the snow mode of a certain brand of RV was tested. After the outriggers touched the ground, they would apply an additional 10 seconds of continuous pressure to prevent the frozen soil from melting and causing unstable support.

Predictive maintenance functions are now becoming more and more intelligent. A modification factory showed me their data: by analyzing the current curve when the outrigger motor starts, it can predict gear wear 200 operations in advance. Just like an experienced driver listening to the engine sound to judge the vehicle condition, the system will record the vibration spectrum of each outrigger deployment, and directly issue a warning when an abnormal waveform is found.

The biggest headache for the repair shop is actually the problem of false alarms. Last year, a cold chain transport truck always reported insufficient outrigger pressure. After three days of investigation, it was found that the temperature sensor was frozen silly-the plastic shell deformed at minus 30 degrees and caused false touches. Now the new system has added an environmental compensation algorithm, just like the low-temperature start strategy of truck diesel vehicles, and the detection threshold will be adjusted according to the real-time temperature.

Motor start

Last winter, a truck driver in Inner Mongolia couldn’t open the electric outrigger on the frozen grassland at minus 35 degrees-later it was found that the motor carbon brush was frosted. The motor start of the truck electric outrigger is like the cold start of a diesel vehicle, which requires both explosive power and overload protection.

There are two types of DC motors used in electric outriggers: brushed motors are cheap and durable but easy to ignite, and brushless motors are three times more expensive but have a long life. A modification factory owner did the math with me: If you use a brushed motor, you have to clean the carbon powder every 300 starts, otherwise it will affect the speed just like carbon deposits in the engine. Last year, after they replaced the cold chain fleet with brushless motors, the failure rate dropped directly from 3 units per month to 1 unit in half a year.

Current control at the moment of starting is the real skill. A better control system will play “soft start”: only 60% voltage is given in the first 0.5 seconds, and full power output is output after the gears are in place. This trick is the same as the half-clutch start of an old driver. It can avoid the mechanical impact of a “clang” sound and prevent the fuse from burning out. There is a counterexample: In order to pursue speed, a domestic outrigger manufacturer directly rotates the motor from a standstill to full rotation, resulting in a broken drive shaft.

The impact of temperature on the motor is more complicated than imagined. At high temperatures, the winding resistance increases, and the control system must automatically compensate for the voltage; at low temperatures, the grease becomes viscous, and some intelligent systems will first let the motor shake three times – just like a truck driver kicking the tire to defrost in winter. Last year, I tested the preheating function of a certain brand: at -20℃, first pass a small current of 2A to heat the motor, and wait until the temperature sensor rises to 5℃ before officially starting. This method can reduce the startup failure rate by 70%.

The most fatal is the stall protection. When the outrigger hits a stone, the current will instantly soar to 3 times the rated value. A good control system is like an experienced old driver, which can cut off the power supply within 0.1 seconds. There is a particularly typical modification case: when adding outriggers to a dump truck, the repairman forgot to adjust the current threshold, and the motor pushed a dent in the frame. The repair cost was enough to buy five new outriggers.

Power transmission

A RV player suffered a loss on the Sichuan-Tibet line: the four outriggers were doing their own things on the slope, and the body almost turned over. The power transmission system is like the differential lock of an off-road vehicle, which needs to provide sufficient power and intelligent distribution.

The core of the transmission mechanism is the planetary gearbox, and the reduction ratio is usually between 30:1 and 50:1. A modification master gave an analogy: “This is like the climbing gear of a truck gearbox, which converts the crazy power of the motor at 3,000 revolutions per minute into the steady power of the outriggers at 2 centimeters per second.” But the gear material is very particular. Although cast steel parts are cheap, they will wear out after running 10,000 times; powder metallurgy can withstand 50,000 times, and the price will be tripled.

Power distribution is the real black technology. For models with four independent legs, each outrigger has a pressure sensor to compete in real time. It’s like four people carrying a sedan chair. If one corner is heavier, the control system will add more power to that side. Test data of a high-end RV last year showed that this system can control the inclination of the vehicle body within 0.3 degrees, which is more accurate than the leveling of a refrigerator.

When encountering soft ground, the power transmission strategy changes immediately. Some systems will play the “ramming mode”: first let the outriggers press down quickly to test, and pause for 0.5 seconds when encountering resistance, and then continue after the ground settlement stabilizes – this trick is learned from the construction principle of pile drivers. When the outriggers are deployed on the beach, the system will automatically perform three tampings, with the pressure increasing by 20% each time.

The loss monitoring of transmission components is becoming more and more intelligent. Some manufacturers have installed vibration sensors in the gearbox, and can predict faults by analyzing the changes in the spectrum. Just like an old mechanic listening to the abnormal sound of the gearbox, the system will compare the noise characteristics of each outrigger deployment. Data from a logistics fleet showed that 17 bearing failures were discovered in advance by this technology, and the direct losses avoided were enough to buy 20 sets of testing equipment.

The route competition between hydraulic transmission and pure electric drive is also very interesting. The hydraulic system is powerful, but the maintenance is as troublesome as serving ancestors; the electric solution is clean and neat, but the explosive power is slightly inferior. There is a comparative data: to support the same 10-ton load, the hydraulic outrigger only takes 3 seconds, and the electric version takes 5 seconds, but the maintenance cost of the electric system is only one-third of the hydraulic system. Now high-end models are starting to play with electric-hydraulic hybrids, just like hybrid trucks, which use electric motors to start and automatically switch to hydraulic assistance when overloaded.

Landing gear extension

Last year, when a semi-trailer of a logistics company was unloading, the four outriggers suddenly extended out of sync, almost throwing a million-dollar precision instrument out of the car – it was later discovered that gravel had entered the worm gear box. The extension of the electric outrigger is like dancing a mechanical dance, and the coordination of each joint must be perfect.

When starting the extension program, the control system must first pass five levels and cut six generals. First, let the gyroscope confirm the tilt angle of the vehicle body, which can reach an accuracy of 0.3 degrees, ten times more accurate than the mobile phone compass. Then the pressure sensor starts working, sensing the hardness of the ground like a Chinese medicine pulse – the feedback pressure of cement and mud can differ by four times. The most intelligent is the speed synchronization detection, the speed difference of the four outrigger motors cannot exceed 5%, otherwise it will immediately trigger an emergency stop.

The strategy for dealing with obstacles is the real skill. Last year, I saw a thrilling scene in the Gobi Desert in Qinghai: when the outrigger pressed down, it hit the rock, and the intelligent system instantly switched to the “vibration breakthrough” mode – letting the motor impact repeatedly at a frequency of 5Hz, and cooperating with the pressure sensor to adjust the strength in real time.

The adjustment of the extension speed is more complicated than expected. When unloaded, it can reach the fastest speed of 12cm/s, but it has to be reduced to 4cm/s when the load exceeds 8 tons. A modification factory suffered a loss: when installing outriggers on refrigerated trucks, the speed curve was not adjusted. As a result, the inertia was too large during emergency stops and the hydraulic cylinder seal was squeezed out. Now high-end control systems can play “speed ramps”, just like an experienced driver stepping on the brakes first heavily and then lightly, so that the extension speed changes according to the S-shaped curve.

The most fatal is the soft ground response plan. When a certain RV player was camping in the wetland, the outrigger sank 15 cm as soon as it touched the ground. The new generation of systems has added a “ramming mode”: first press down quickly to test, and pause for 0.5 seconds when encountering soft ground, and then continue when the soil density meets the standard. This method is similar to the construction principle of a pile driver, which can improve the support stability by 37%.

Status Feedback

A cold chain fleet suffered heavy losses last winter – the temperature sensor misjudged frost as a leg failure, causing loading and unloading delays and freezing a truck of seafood. The status feedback system is like an old mechanic who is on duty 24 hours a day for the car. It must be sharp-eyed and able to eliminate false alarms.

When the leg is running, 32 sensors are reporting in sync: the pressure sensor mutters “the left side is heavy”, the temperature sensor yells “the motor is hot”, and the angle sensor complains “the body is crooked”. The control system must be like an experienced team leader, picking out the real problem from these mixed messages. Last year, there was a classic case: the vibration sensor alarmed that the gear was worn, but when it was disassembled, it turned out that the fixing bolt was loose – the misjudgment rate is comparable to that of a new mobile phone repairman.

Multi-sensor data fusion is the core technology. A better system will use the Kalman filter algorithm to crush and re-combine the data of different sensors. Just like the traditional Chinese medicine doctor’s comprehensive diagnosis of observation, smell, questioning and palpation, the system will compare three sets of data: pressure curve, current fluctuation and vibration spectrum. Data from a modification factory shows that this algorithm can reduce the false alarm rate from 18% to 3%.

The processing strategy when encountering signal conflicts is particularly interesting. For example, the angle sensor says that the body is tilted 2 degrees, but the pressure sensor shows that the four legs are balanced – at this time the system will start the “voting mechanism”. Last year, the decision logic of a German RV was tested: when more than three sensor data are contradictory, it automatically switches to manual mode and flashes the warning light. This process is exactly the same as the emergency stop processing of CNC machine tools.

Predictive maintenance is getting more and more popular now. By analyzing the current curve when the motor starts, the carbon brush wear can be predicted 300 times in advance. Just like an old driver listening to the abnormal sound of the engine, the system will record the vibration characteristic spectrum of each extension. The actual combat data of a logistics company: 23 bearing failures were discovered in advance with this technology, and the losses avoided were enough to buy 50 sets of testing equipment.

The most troublesome problem is environmental interference. Last year, the outriggers of a tanker truck kept reporting insufficient pressure. After three days of investigation, it was discovered that the sensor housing was swollen due to sun exposure. Now, new systems have added environmental compensation algorithms, which will adjust the threshold in real time according to temperature and humidity – this idea is exactly the same as the intake correction of diesel vehicle ECU. In extreme environments of -30℃ to +60℃, the feedback error is always controlled within ±1.5%.

The life of the electric outrigger is about 12,000 times of lifting or 8 years (daily use ≤5 times). Coastal users need to spray machine tools with anti-rust wax every season, regularly calibrate the synchronization error of the four legs to ≤2mm, and avoid single-side load exceeding 50%, which can be extended to 10 years+.

Material quality

Eight out of ten times, the hydraulic outrigger cylinder explodes due to the material. The wall of a good outrigger is like a military gun barrel, and sparks will fly when it is ground with a grinding wheel. Last time when I disassembled an imported outrigger, I found a detail: The inner wall has a spiral stress groove, which is similar to the oil line design of the CNC machine tool guide rail, which can disperse the pressure peak.

The “aviation aluminum” on the market now has a lot of water, and the real thing is cold-forged alloy steel. There is a simple way to detect it: use a vernier caliper to measure the thickness of the tube wall. If the nominal 5mm is actually less than 4.3mm, it will be passed directly. The most outrageous e-commerce hot-selling product I have seen is marked as 4mm, but the actual measurement is only 3.1mm, and the weld is like a dog bite.

Surface treatment is the invisible killer. The case of coastal users being corroded by salt spray in three months is not a scare tactic. A truly reliable one should at least have three layers of protection: bottom phosphating treatment + middle epoxy resin coating + outer polyurethane spraying. It is the same as the sheet metal protection of the machining center. If one process is missing, the life span will be cut in half.

The hardness of the material should not be too much. Last year, a modification shop nitrided the outriggers, and the hardness was up to 60HRC, but it broke directly in the northeast in winter. Now high-end models have begun to learn the gradient heat treatment technology of machine tool screws, the core maintains toughness, and the surface is strengthened and wear-resistant.

Last month, I met a ruthless person on National Highway 318 who used the cutting fluid of CNC machine tools as outrigger lubricant, and the sealing ring was all soaked. This thing is like using kerosene to wipe the guide rails of machine tools. It looks bright but actually destroys the equipment. If you really want to maintain it, you must use lithium-based grease specifically for the outriggers, and add oil every 500 times of lifting and lowering.

Frequency of use

Old drivers who play trailers all understand the formula: Number of lifts = life reduction coefficient. Imported big brands claim a lifespan of 20,000 times, but that’s laboratory data – constant temperature environment + 2-hour cooling interval each time. In reality, construction sites are rushing to work and continuously lifting? It’s the same as a CNC machine tool running continuously without heat dissipation.

Let’s take a look at a real comparison:

Gear oil is the invisible killer. I’ve seen a performance team that hasn’t changed the oil for three months, and the lubricating oil is as thick as sesame paste. Working under this condition is equivalent to dry grinding the CNC machine tool guide rails, and the outrigger reduction box is directly scrapped. Veterans have a rule of thumb: oil must be changed every 500 lifts, and 300 in advance in summer.

Motor heat dissipation design is the real work. A good outrigger motor housing has spiral heat dissipation grooves, which is the same principle as the spindle cooling system of a machining center. Last year, I dismantled a German outrigger, and found that a miniature fan was stuffed into the motor. The temperature control did not exceed 65 degrees after 10 consecutive lifts.

Load weight

Nominal 8 tons load? That is the static load of a single leg! Dynamic impact loads that exceed 3 seconds are dangerous. The most outrageous modification I have seen is that the RV outriggers are used as jacks. When unloading the tire, there is a bang and the outriggers are bent inward directly – The instantaneous impact force can reach 4 times the nominal value.

Load distribution is fatal:

Horizontal sensors are more important than load-bearing. Just like the alignment of CNC machine tools, if the outriggers are slightly tilted by 2 degrees, the actual load distribution can differ by 40%. The black technology of a modification factory: add a monitoring system similar to the machine tool grating ruler to the outrigger, and automatically alarm when the eccentric load exceeds 5%.

There are signs of overweight warning: abnormal sound when the outrigger is retracted, the hydraulic cylinder rebounds slowly, and the motor starts delayed for more than 0.5 seconds. These are all fatal signals. Just like the precursor of wear of the machine tool guide rail, when the outrigger is visibly deformed, it is basically not far from the cylinder explosion.

Last month, I saw a tragedy: a 3-ton RV was loaded with 6 tons of building materials. The outriggers supported it for 20 minutes and nothing happened. Just when I was about to breathe a sigh of relief, I heard a “click” sound – it was not the outrigger that broke, but the beam was deformed by the top! This is the same as using CNC machine tools over the range. You think the equipment can withstand it, but in fact the structure has been damaged for a long time.

Working environment

Those who use outriggers at the seaside know that the salt spray corrosion rate is 7 times that of inland areas. The better outriggers will learn from ship equipment to do sacrificial anode protection. The most ruthless protection I have seen is to spray the outriggers with anti-rust wax for machine tool guide rails, which is applied once every three months and is more effective than the original coating.

Comparison of death methods in different environments:

Temperature difference is the hidden boss. The 30-degree temperature difference between day and night in the Alashan Desert can cause microcracks in the outrigger aluminum similar to thermal deformation of machine tools. There is a trick: leave a 2mm gap when the outrigger is folded, which is the same principle as the thermal compensation gap reserved for CNC machine tools.

The grounding method determines life and death. Directly outriggering on gravel ground is equivalent to letting the machine tool work in a vibrating factory. Experienced drivers always bring two 10mm steel plates as pads. Actual data from a modification factory: the probability of outrigger overload dropped from 37% to 12% after padding with steel plates.

Operation habits

Ninety percent of outriggers die prematurely because of bad hands. The most outrageous operation I have seen: kicking the outrigger hard to “help” during lifting and lowering. What is the difference between this and hitting the guide rail of a CNC machine tool with a hammer? Hydraulic outriggers are most afraid of instantaneous impact loads.

Operations that affect life:

1. Adjusting the level while lifting and lowering;

2. Using one-side outriggers beyond the limit;

3. Forced cooling of motor overheating;

4. Using a jack to assist lifting;

5. Driving without fully retracting the legs;

Synchronous error exceeding 2mm is a time bomb. Precision outriggers should be calibrated synchronously every three months, just like debugging CNC machine tools. A certain RV club measured that the gear wear rate was reduced by 65% after calibration.

Emergency stop operation ruins everything. Stage car veterans know: 3 seconds before the end of lifting, you must switch to low gear. Direct power off is like emergency stop of the machine tool spindle, and the reduction gear will break in minutes. There is a data comparison:

• Standard operation group: average life 12,000 times;

• Emergency stop group: average life 3,000 times;

Last month, I saw a stage car operator who pressed the three buttons of lifting + leveling + rotation at the same time, and the outrigger was twisted into a knot on the spot. This is the same as the three-axis linkage of CNC machine tools losing control – Electromechanical equipment is most afraid of multi-threading.