Back to Technical Information Strength and Safety Durability Chassis Seat Mounting Strength and Safety The WmegaTrac® with the TEFTEC made EZ Lock compatible engagement pin was crash tested to 25 mph at EZ LOCK lab with a 175 pound dummy on board. A total of 3 crash tests have been performed on the same WmegaTrac® specimen and it still is in demonstrator service. No damage occurred to the WmegaTrac® Crash loads were above 18 Gs. Aircraft crash tests are at 9 Gs and always result in severe damage of the specimen being tested. 18 Gs at the WmegaTrac® test weight of 385 pounds and the dummy at 175 yielded loads of 10,080 pounds at the frame anchor point. In January of 1999 a user was in an WmegaTrac® in a van when the van was involved in an accident. The van was totaled in the accident. We are told that the user was uninjured and the WmegaTrac® suffered only joystick damage. In the fall of 1998 a young lady in an WmegaTrac® was hit broadside in LA by a Ford F250 truck as she crossed a street. The truck was stopped by the WmegaTrac® and suffered damage. The WmegaTrac® received two damaged wheel spiders, bent rim tabs and a badly damaged seat frame. The user received a headache. The WmegaTrac® was driven from the scene, although it was wobbly on its bent wheels. Main wheels and the seat were replaced and some cosmetic repair to scratched surfaces was done to return the unit to service. Its owner said she owed her life to the WmegaTrac®. Except for the main wheel rim tabs and spiders, there was no damage to the WmegaTrac® powerbase. Safety is a team effort and the wheelchair driver is a major member of the team. Always consider the possible results for each operation of the wheelchair. If the possible results are catastrophic, then there is little reason to proceed with the operation. As an example, it is tempting to go out on a narrow boat dock when others are out there having a good time. On possible result for driving out on the narrow boat dock is stray radio waves or an unexpected spasm could propel the wheelchair off the end or side of the dock and the person in the wheelchair could drown. This is a poor risk-reward ratio and should never be given a chance to cause the problem. A person should never operate a wheelchair in such a way that they cold become stranded alone, or fall into water deep enough to drown. Passersby would not know how to extricate the wheelchair user from his chair. Each year, there are news stories of persons in wheelchairs venturing off alone in extreme heat or cold with no way to ask for help, becoming stranded by bad batteries, deep mud, driving off the pathway, driving off a cliff, or other mishaps and dying of exposure or injury before help finds them. If a grade could result in upset either statically or from acceleration or deceleration, then find a way around the grade or choose an alternate path with a non-dangerous grade. Remember, accelerating uphill in a rear wheel drive chair or decelerating going down hill in a front or mid wheel drive chair may exceed the wheelchair's dynamic limit, resulting in a tip over. If a grade is questionable, have an able bodied person alongside to prevent the chair's upset. Top of the Document Durability The WmegaTrac® and BetaTrac® were designed to not wear out. These powerbases have renewable parts like an automobile. All TEFTEC products are designed with very large margins. All bearings are ball or rollers except for two of the twenty gears in the transmission, which have long life, sintered bronze bearings running in an oil bath and are not in the drive circuit. This is common practice in automotive for low speed or seldom used bearings. The drive axles are 1-inch diameter at the smallest point. They weigh several pounds apiece and are larger than most stub axles in front-wheel-driven cars. Primary wiring is 6 gage. This is several times the thickness used in other power chairs. Bolts are generally above 100,000-p.s.i tensile strength. Most components are high carbon steels such as 4130 and 4340 or high strength stainless steel or aluminum. Long-life polyurethane elastomeric bushings are used in the suspension. Linear actuators for seat recline, seat tilt, and seat elevating are 1,000 pound rated, larger than those in other power seating. Most of the gears and bearings are larger than those in automotive transmissions and make those in other wheelchairs look like toys. There are 34 ball and roller bearing assemblies and 22 gears in the transmission alone. Top of the Document Chassis Since its inception, the WmegaTrac® chassis incorporates multiple suspension links similar to that only recently adopted by General Motors in their newest sport truck designs. Monroe or Gabriel shock absorbers, 2.5-inch diameter coil springs, heat-treated components, polyurethane elastomers, ball joints, anti-shimmy casters and a host of similar features are standard in the WmegaTrac® chassis. Frames for TEFTEC bases are designed and constructed to withstand severe loading and accommodate installations of various seating and accessories. Frames are steel weldments that are powder coated for corrosion resistance. Wiring is secured to prepared frame tabs. Adjustable air suspended models incorporate frame mounted Schrader Valves for remote servicing of air suspension and can also provide compressed air for tires from the on-board compressor. Provisions are made for EZ LOCK using a TEFTEC manufactured lockpin. Top of the Document Seat Mounting Multi-mount rails with two parallel rows of mounting holes laterally displaced by 11.5 inches are provided. These holes are on .75-inch centers longitudinally. Eight automotive 5/16 NC relocatable clip nuts are provided. Top of the Document