Lift Failure....

[Ironcrow]

The lift in the video is a little misleading. It didn't fail at 10,000 pounds, it failed at 15,000 pounds. Granted, they said in the video that the industry standard is for a lift to function at 1.5 times the rated weight which sounds to me like a pretty good standard.

Another thing to note about the lift in the video. The hydraulic motor could not raise the 10,000 weight. They had to use another motor. Once they got it to raise, there was a lot of deflection of the rear arms. They had to go to extremes to get the lift to fail.

Good comment. In a meager defense of that lift manufacturer; the last line of defense is the designer making the lift hydraulics simply unable to lift a load that will break the unit.

Apparently this lift is marketed as a 10,000 lb capacity and could not lift 10,000 pounds. Ideally, you'd think they'd rate it at 10,000 pounds, make the hydraulic system good for 10,100 pounds (with a pressure limiting bypass valve), and load test the structure to 15,000 lbs.

Personally, I'd not want to see ANY obvious deflection of major structural components at anywhere near the rated capacity. This means I would design to deflection not ultimate loads.

 

[Longbob]

longbob, the demo was to see if the lift was safe as per the claims of 10k rating.........true the lift was over loaded but to a standard all lifts are tested to............if it's 10 k and won't handle the testing procedure, shouldn't be allowed to be sold..........as for the hyd, part, what would be keeping someone to think they could safely assume their 9,996 lb truck should be able to be handled and the individual eithe tweaks the hyds. or replaces with adequete capacity and experiences a failure over time due to fatigue...........i believe the person responsible for making the decisions for thses types of marketing ploys should be forced to stand under their product they are lying about by law.........truth in advertising..........

It shouldn't allowed to be sold? Or it shouldn't be allowed to be sold and marketed as a 10,000 lb lift?

I think the last question is more accurate if the lifts being sold are to meet the industry standard of 1.5 times capacity. Frankly, I wasn't aware of that being the standard. If it is, then it does give me more comfort.

If you do a little research on these lifts you will see that they are virtually all of the same design and possibly the same manufacturer. The testing and links by Greg Smith Manufacturing is showing a near identical lift that they sell and it carries a 9,000 lb rating.

I can see where Greg Smith Manufacturing is getting their hackles up if a competitor is selling the same lift and advertising it as a 10,000 lb lift when GSM only offers a 9,000 lb lift for the same price. It is more unfair trade practices than anything and a "possible" safety issue.

For example: If Greg Smith Manufacturing tested the offending lift to the industry standard of 13,500 lbs (1.5 x 9,000), then I would like to see if that lift still failed. 1,500 lbs is a lot of difference.

So, back to my original questions. If the first question is what you are saying, then it is possible that Greg Smith would need to pull their lifts off the market due to a safety issue. I don't think that is the case and I am making the assumption that they are actually the same two lifts with different advertised capacities.

I reserve the right to be wrong on all points.

 

[Longbob]

Good comment. In a meager defense of that lift manufacturer; the last line of defense is the designer making the lift hydraulics simply unable to lift a load that will break the unit.

Apparently this lift is marketed as a 10,000 lb capacity and could not lift 10,000 pounds. Ideally, you'd think they'd rate it at 10,000 pounds, make the hydraulic system good for 10,100 pounds (with a pressure limiting bypass valve), and load test the structure to 15,000 lbs.

Personally, I'd not want to see ANY obvious deflection of major structural components at anywhere near the rated capacity. This means I would design to deflection not ultimate loads.

I agree completely.

 

[Winmon]

FWIW, here are the Certifications & Standards that the better lifts will be tested through ...


ISO9001 certification
ISO9001 is the HIGHEST international benchmark of quality. This highly exclusive certification means that Rotary's Quality Management System is among the best in the world. Customers dealing with an ISO9001 certified company know that the firm has undergone rigorous quality testing and will continue to meet these high standards on an ongoing basis.

The ISO9001 certification process is based on a wide variety of separate elements of the quality management system. An independent, accredited auditing agency verifies that those elements are consistently present, then a certificate of compliance is awarded.

It takes a tremendous commitment of resources and effort to met the requirements, but ISO9001 certification puts a company on equal footing with some of the most respected and quality-driven firms in the world.

Research shows that firms certified to ISO9001 standards significantly outperform competitors in many of the main business ratios. Our ISO9001 certification demonstrates our commitment to provide the highest quality lift products in North America, states Gary Kennon, president of Rotary Lift. "Our customers have recognized Rotary as the world class lift manufacturer."


North American Lift Standards
The Automotive Lift Institute (ALI) was formed in 1945 to ensure that lifts were being constructed to adequate safety standards. Rotary Lift was one of the founding members, and has been active in the organization for over 50 years. Through the years, ALI sponsored nationally accepted construction and performance standards.

In 1993, the ALI and its members began a rigorous testing and certification program for lifts. The program uses an independent third-party testing laboratory called ETL. ETL meets OSHA requirements as one of only 18 Nationally Recognized Testing Laboratories in the country. ETL tests the lifts to insure compliance with the American NationalStandard ANSI/ALI ALCTV-2006 and ANSI UL Standard 201 and periodically inspects the factory where the lifts are made. If the lift passes the tests and the factory meets the standards, then the lift may carry the gold "ALI Certified/ETL Listed Mark."

An ALI/ETL certification also requires that complete instructions, manuals and safety documents be included with the lift. It's important for a lift buyer to understand that just because a lift manufacturer states that a lift is ALI/ETL certified, this is no guarantee that all of its lifts are certified. Each individual lift model must receive is own ALI/ETL certification.

Today, a majority of the lifts sold in the U.S. and Canada are ALI/ETL certified. This makes it very easy for dealers to enjoy the confidence and peace of mind that comes with selecting certified lifts for their shop. Are the non-certified lifts safe? Will they stand up to long term use? [E.K. Fox, president of ALI states, "The proof is in the testing! Maybe they're safe, maybe not. Without that ALI/ETL seal on the label, you can't really know for certain what you're getting yourself into."


International Standards
In addition to the ISO9001 and ALI/ETL certifications, many of Rotary's products also meet the rigorous standards for Canada (CSA), Europe (CE) and Germany (TUV).

To meet CE Certification standards, a Notified Body must be involved in the process. The process varies depending on whether there are harmonized standards for the product or not. In the case of vehicle lifts, there are no official standards at this time. Here, the Notified Body inspects the product, verifies tests, and receives documentation on the product (Technical File). The Notified Body then issues an EC-type Examination Certificate (CE Certificate). This certificate is referenced on the Declaration of Conformity to Type that the manufacturer issues.

The CE mark can now be placed on the product. If someone questions the validity of the CE mark, the Notified Body has a Technical File to show verification that the product meets standards.

As for TUV vs. CE, we used TUV to verify our CE compliance. This is similar to ETL verifying that our domestic lifts meet ALI Standards. The fact that TUV has a reputation of being strict in their interpretation of standards (we found this out in the arguments we lost with them during their inspection), adds to the credibility of our product. Other Notified Bodies may not spend the time paying attention to detail like TUV does. This is why TUV carries more "clout" than other agencies and why some people put more emphasis on seeing TUV on a product than just seeing CE.

 

[Longbob]

Winmon,

Thanks for posting. Maybe it is just me, but I would like to see some specifics like the 1.5 times reference or something. It just sounds like a lot of legal speak or more like a press release.

 

[Greg9504]

Thats a Hofmann screw style lift.

As Dmaxman has said, that lift is a HOFMANN lift . There are several ways to identify as one:

- Note the electric motor at the top. It's a 3 phase 5 hp.
- no hydraulic reservoir, as there are no hydraulics
- the bottom plate

The electric motor turns a pulley, turning the ACME screw rod that the lift arms ride up and down on. On the bottom of the threaded rod there is a sprocket, then a chain that runs under the bottom plate, to a sprocket on the bottom of the threaded rod on the other side, so they move in unison.

ACME threaded rod:

The nut would be either brass or a plastic of some type:

ACME threaded rod (screw rod) is self braking, meaning without any other locking device the lift will not move down unless powered down. That is unless the nut is so worn it no longer works, as in the case above. The failure is a direct cause of the owner/operator neglect. In Ontario, while I am not sure if it is law, most lifts are inspected once a year. If that one passed inspection then the owner should be having a long talk with the service tech who did the inspection.

I have one just like it rusting away in my yard that I picked up for $75. I planned to use it for something nonautomotive.

 

[NRChopshop]

Am i the only one that noticed the wall on the left is......a bit off?

 

[Art From De Leon]

Am i the only one that noticed the wall on the left is......a bit off?

Perhaps the building is a Quonset Hut, or a Behlen Curvet building, and the area between the curved wall, and the drywall is insulated?

Also, some Butler steel buildings have a sloped sidewall.

 

[Winmon]

Quote:
Originally Posted by Dmaxman
Thats a Hofmann screw style lift.

As Dmaxman has said, that lift is a HOFMANN lift . There are several ways to identify as one:

Thanks Dmaxman and Greg!

The nut would be either brass or a plastic of some type:


ACME threaded rod (screw rod) is self braking, meaning without any other locking device the lift will not move down unless powered down. That is unless the nut is so worn it no longer works, as in the case above.

Wow, why in the hell would the nut be made out of brass or plastic I wonder? Cost I guess?? From the design, sounds like a VERY critical part...

 

[Ironcrow]

Wow, why in the hell would the nut be made out of brass or plastic I wonder?

Noise, vibration, toleration of misalignment, self lubricity. ACME nuts can also be made of stainless steel, titanium, whatever.