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Tim
User Rank
Platinum
Design without bearings
Tim   4/20/2012 7:29:03 AM
Garage door openers move the heaviest moving object in your home, so it is surprising that the designers would omit a load bearring from the rotating object.  However, it is still common to see metal on metal contact in consumer items.  Ususally, the difference between professional and a consumer model from any manufacturer is the quality of the shaft bearrings.

naperlou
User Rank
Blogger
Re: Design without bearings
naperlou   4/20/2012 10:08:52 AM
Tim, even though consumer models do not go through the duty cycles of an idustrial product, poor design is not a good thing.  As noted in the article, the two homeowners bought other brands. 

Rob Spiegel
User Rank
Blogger
Re: Design without bearings
Rob Spiegel   4/20/2012 1:44:03 PM
Good point, Naperlou. This brand lost two customers -- and probably hundreds of others. I would also think there is a liability danger for damage to cars or people.

Charles Murray
User Rank
Blogger
Re: Design without bearings
Charles Murray   4/20/2012 5:38:30 PM
NO RATINGS
I wonder if this is an oversight or a deliberate design decision to save money. Either way, it's amazing that the company let the product out the door that way.

warren@fourward.com
User Rank
Platinum
Re: Design without bearings
warren@fourward.com   4/20/2012 6:19:22 PM
NO RATINGS
They had a obsoletion engineer (BSOE) on staff.  Lack of quality is job 1 (sorry Ford).

warren@fourward.com
User Rank
Platinum
Re: Design without bearings
warren@fourward.com   4/20/2012 6:20:41 PM
NO RATINGS
My mother-in-law is the heaviest object in my home...

tekochip
User Rank
Platinum
Dig a little
tekochip   4/21/2012 10:03:06 AM
NO RATINGS
The door is supposed to be balanced so that there is very little load on the opener, but still, you'd think that the cycle life would dictate a bearing on the output shaft. I have a friend that owns a garage door business, so I'm going to dig into this one a little bit.


tekochip
User Rank
Platinum
Confirmed
tekochip   4/21/2012 10:43:38 AM
NO RATINGS
OK, I talked to my garage door guru and here's the story. Without naming names (I have friends that work for the company involved), the shaft routinely breaks on the chain version of the opener. If there's too large a load on the opener, like an improper or broken spring, or if the chain is too tight the shaft will start to wear. My door guru always carries a couple of repair kits for the chain version because the failure is very, very common. The belt version of the opener doesn't have the same problem even though it doesn't use a bearing either. There's enough play in the belt and the rubber motor mount of the belt version to prevent failure.


naperlou
User Rank
Blogger
Re: Design without bearings
naperlou   4/21/2012 2:11:26 PM
NO RATINGS
Careful, warren, you could get into trouble with that!

3drob
User Rank
Platinum
Re: Design without bearings
3drob   4/23/2012 9:18:57 AM
NO RATINGS
I think it's pretty clear this wasn't an oversight (since it failed out of warrantee).

Somebody probably got a hefty bonus the year they decided to cut the BOM by a couple $ (look at all the money they've saved over the years).  Had the observer not been an Engineer, nothing bad would have happened to the manufacturer's reputation on discovery of this bad design.

Oh, wait.  Nothing bad has happened to the manufacture's reputation since we still don't know who it is.  But other manufacturer's also read this blog, so now they have an idea for future cost savings ...

Now I'm going to inspect mine when I get home.

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