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Made by Monkeys

Snafus With the Speakers

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Scott Orlosky
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Making it work
Scott Orlosky   10/31/2012 10:09:26 AM
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I really enjoyed this story since it addresses the real world issues of manufacturing.  It's fine to design something on a CAD program, but somewhere along the line, the actual parts have to be assembled and that, it turns out, is every bit as important and the design itself.  Attention to detail, proper assembly techniques, training and clear work instructions all matter.  Thanks.

naperlou
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Re: Making it work
naperlou   10/31/2012 11:01:46 AM
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Scott, that is a good point.  This reminds me of a number of situations I have seen with small manufacturers over the past few years.  The problem was parts testing over time (life testing).  You really need to trust your supplier or have a good warranty program.  On the other hand, even with a good warranty the failure often leaves a bad taste with the consumer. 

Tim
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Re: Making it work
Tim   10/31/2012 8:06:38 PM
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This story exemplifies the importance of good work instructions. A good system will account for a new employee and still make quality product. Documentation of task steps and quality risks on each step is important.

jmiller
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Re: Making it work
jmiller   10/31/2012 10:23:06 PM
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I agree with the use of good instructions or standard operating procedures.  However, I don't like the idea of standard operating procedures being, "bring it to me and I'll fix it with some baling wire and twine."

notarboca
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Re: Making it work
notarboca   10/31/2012 11:52:42 PM
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Even with a good statement of work, I asked the manufacturing staff for "as built" drawings to try to catch things like this.  Wouldn't have had an effect on the magnet glue problem, though.

cookiejar
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Re: Making it work
cookiejar   11/6/2012 7:33:17 AM
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It seems obvious in hindsight that the reason for the really good price on the speakers was that they had a hidden flaw, which was discovered after the horse had left the barn.   

If it seems too good to be true, it usually is. 

Buyer beware etc. etc. 

Q.C. and testing on a limited budget are hit and miss when you don't know what you're looking for.  I'm sure in the future, any speakers will be tested for magnet retention.

jmiller
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Re: Making it work
jmiller   10/31/2012 10:16:29 PM
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And in this case it sounds like someone forgot to check and see if the glue would give the product the life it needed.  Could have been one of those cost out ideas.  Or more than likely, someone just thought it would work as good as the other stuff.

jmiller
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Re: Making it work
jmiller   10/31/2012 10:21:22 PM
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I liked the article as well.  Kind of makes one wonder if the tolerance stack was done to understand if the process was capable of producing repeatable parts with the process being used.

tekochip
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Odd Failure
tekochip   10/31/2012 10:55:34 AM
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I spent a lot of years as a club musician and speakers were tossed around quite a bit, not like Pete Townsend, but things get dropped, bounced around on the stage, and in vans.  I've heard voice coils rub, seen them melt, and shatter (titanium horns).  I've seen surround dry rot and fatigue, but I've never seen a magnet fall off, not even on the big 20lb magnet JBLs.  This sounds like a pretty low quality vendor.


Battar
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Expensive failure
Battar   11/1/2012 9:24:18 AM
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When a 15$ radio fails because of poor quality components it's my fault for buying rubbish in the first place. But if I buy a top quality audio product, maybe a radio from a company whose name sounds like an Italian dish, or a term in trigonometry, or the capital of a US state, I don't expect it to fall apart because someone saved a few pennies in production, or sold "quality" at "quality price", without actually verifying the quality of the product. In the long run, the cheap mass produced products have more stringent manufacturing procedures and automated final test methods, and are more reliable.

Rob Spiegel
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Re: Expensive failure
Rob Spiegel   11/1/2012 12:56:51 PM
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This story also illustrates how one cheap component makes the entire product cheap. With a high quality product, each and every aspect of the product and the production needs to be high quality.

William K.
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Speaker failures
William K.   11/1/2012 5:42:23 PM
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The choice of a poor quality glue is as much a design flaw as any other. Of course, a much better design would have included a shape detail that would hold the magnet in the correct position. And some speakers haveincluded a sheetmetal stamping that serves no purpose except to assure that the magnet stays in the correct position. 

The fact is that delivering top quality usually means providing more than only just enough to meet the specifications. I am fully aware that there are those that will challenge this concept, and claim that just barely meeting specifications is all that it takes, but those folks only know about maximizing profit and probably are unaware of what actual high quality consists of.

Frank Karkota
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Iron
Speakers and quality control
Frank Karkota   11/1/2012 7:33:50 PM
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One of the hardest parts of manufacturing is quality control, especially for a small company.  As noted, the cabinets were made of oak.  The saw mills do not have tight quality control and thus occassionally wood is slightly thicker.  This was too rare to make a fuss and took only minutes to correct.  Occassionally mistakes are made and must be corrected.  

 

Regarding the speakers, they appeared to be very high quality.  The problem could have been poor glue, or improper application.  It could also have been too cold when the speakers were made.  Or maybe the manufacturer was just sloppy.

 

Getting good parts is not as easy as it seems.  A number of years ago, I bought 10,000 capacitors from a highly reputable US manufacturer.  They were used for general bypass and coupling.  After six months of use, they started leaking (internal resistance dropped) and the commercial receivers started failing to the point where the system failed.  It was expensive to recall and replace perhaps 5000 capacitors.  I have never had that happen with Chinese parts.

 

Regarding documentation, with a staff of four employees, we did not have time to document everything, especially if it was a rare occurance, such as cabinets out of tolerance.  Nobody is perfect!!!

Rob Spiegel
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Re: Speakers and quality control
Rob Spiegel   11/2/2012 2:37:30 PM
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Frank, when you had the problem with the capacitors did you investigate to determine whether the capacitors were counterfeit? This sounds like a classic counterfeit problem.

Frank Karkota
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Iron
Re: Capacitors
Frank Karkota   11/2/2012 7:32:54 PM
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This was back in the mid 1990s and I got the capacitors directly from the manufacturer--no middleman. Of course, they might have outsourced the parts.  It was one of the most reputable makers of capacitors in the world.  You just can't tell!

I have never had that problem with Chinese made capacitors.  The company is still in business, so what happened to me must have been an aborration, a very costly aboration.

Rob Spiegel
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Re: Capacitors
Rob Spiegel   11/5/2012 2:00:52 PM
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Thanks Frank. Counterfeit parts can come through reputable dealers or suppliers when the accept returns. Also, I would guess the legitimate parts made in China would be fine. So the problems I hear about are not from all Chinese parts, just the counterfeit parts.

Cadman-LT
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Re: Capacitors
Cadman-LT   11/5/2012 2:41:17 PM
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I agree. You hear about counterfeit parts all the time. It's almost like the black market for parts. You hear about it alot with computer chips.

Rob Spiegel
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Re: Capacitors
Rob Spiegel   11/5/2012 4:09:36 PM
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Hi Cadman-LT. Yes, counterfeiting is widespread. It takes a wide range of forms. In some cases, a factory that is making components for a U.S.-based company during the day shift will run a nightshift where they make the same components to sell as counterfeits. So the parts are good, but they've stolen the IP from their customer.

Battar
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Re: Capacitors
Battar   11/7/2012 3:29:08 AM
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Why do the counterfeit on the night shift? Daylight is good, too. Our former CEO once worked for a company which outsourced production to a nameless country (whose national flag is mostly red in color), and on a visit to the factory they discovered that alongside parts being produced with the company logo, identical parts were being produced with no logo. They probably went to the internal market, not export.

Rob Spiegel
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Re: Capacitors
Rob Spiegel   11/7/2012 11:03:01 AM
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Battar, those parts may have gone to the external market as well, in which case they were good parts, but counterfeit nonetheless. I once did an article that discussed that some of the counterfeits (such as in this instance) were actually good parts. That statement caused quite a few fires out there in the parts distribution world.

Cadman-LT
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Re: Capacitors
Cadman-LT   11/14/2012 12:03:49 PM
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Rob, I had no idea that was going on. All I ever heard was good companies here in the US were buying parts from ...say China...and they were counterfeit.

Cadman-LT
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Re: Capacitors
Cadman-LT   11/14/2012 12:06:02 PM
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From what I have read, I'm not talking small companies. Big big companies getting counterfeit parts. It seems to be a big deal.

Cadman-LT
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Re: Capacitors
Cadman-LT   11/14/2012 12:10:05 PM
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Is it possible that a little part of the reason things don't last as long as they should is because of counterfiet parts? Just a thought.

Rob Spiegel
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Re: Capacitors
Rob Spiegel   11/21/2012 2:59:49 PM
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That may certainly be the case, Cadman-LT. Many companies end up using counterfeit parts without knowing it. But there seems to be a lot of other reasons products are failing to last. Shifting manufacturing to Asia sees to run coincidentally with lower quality products.

Frank Karkota
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Iron
Re: Capacitors
Frank Karkota   12/1/2012 7:09:27 PM
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Regarding the capacitors that failed, I doubt that it was counterfeit parts, but contaminated dielectric.  The capacitors were made in the US and purchased directly from the manufacturer.  They were leaded monolithic chip capacitors.  I suspect that the dielectric was contiminated during the making of the chip, or by the rosin used in the soldering, or even by the cleaning after soldering, or maybe even by the epoxy coating.

Of course, the chips may have been made overseas and purchased by the US capacitor manufacturer for fabrication into the leaded package, but in that case, the US manufacturer would have purchased them directly from the factory and not through an agent or distributor.

Regardless of the cause of the failure, it was costly for me to replace thousands of capacitors mounted on double sided board, with most capacitors soldered through a ground plane!

Rob Spiegel
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Re: Capacitors
Rob Spiegel   12/3/2012 2:00:44 PM
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That sounds pretty horrible, Frank. How did the manufacturer respond when you alerted them to the problem? 

Frank Karkota
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Iron
Re: Capacitors
Frank Karkota   12/3/2012 2:04:51 PM
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The manufacturer filed a lawsuit against me because I refused to pay for the defective capacitors.  Running a small business without an honest and capable lawyer is impossible!

Rob Spiegel
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Re: Capacitors
Rob Spiegel   12/3/2012 5:03:05 PM
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That's quite a story, Frank. Were you not able to show the manufacturer that the capacitors were faulty?

Frank Karkota
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Iron
Re: Capacitors
Frank Karkota   12/3/2012 7:32:42 PM
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Yes Rob, when you put an ohmmeter across a 0.1 uf capacitor and measure 100 ohms or 1000 ohms, that is proof that the capacitor is bad.  When you have hundreds of capacitors that show similar leakage, you have proof of defective parts.  Furthermore, I am not the only manufacturer who had similar problems with these parts.

Keep in mind that this is a US manufacturer.  I never had this problem with Chinese capacitors!

Rob Spiegel
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Re: Capacitors
Rob Spiegel   12/3/2012 8:38:21 PM
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That's awful, Frank. Why didn't they cop to their mistake and correct it? Seems like an easy snafu to understand and correct.

Frank Karkota
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Iron
Re: Capacitors
Frank Karkota   12/4/2012 9:29:41 PM
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This was just such an incredible mess!  I sold the receivers to the company that developed the system.  He sold the receivers to the Farm Bureau, which put the receivers in the homes of farmers, so that they could get useful information via data.  (This was before the internet.)

When the capacitors failed, the system failed and the Farm Bureau had to retrieve and replace the receivers at great cost.  Everybody was hurt.

When the capacitor manufacturer sent a lawyer after me, I turned it over to my lawyer.  My lawyer settled the lawsuit by telling the manufacturer's lawyer that if he drops the suit against us, we would not sue them for damages.  The lawyer's bill almost equalled the amount of the suit.

Shakespeare had the right solution in Henry VI!

Rob Spiegel
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Re: Capacitors
Rob Spiegel   12/12/2012 5:27:05 PM
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Yes, Frank, Shakespeare had the right solution. It's still a shame you didn't get made whole.

Cadman-LT
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Re: Capacitors
Cadman-LT   2/12/2013 8:34:18 AM
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Well that is what I mean. Companies that THINK they are buying one thing are getting another without ever knowing. It's a big problem. Something needs to be done and I think the gov has started. I think.

Cadman-LT
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Re: Capacitors
Cadman-LT   2/12/2013 8:34:18 AM
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Well that is what I mean. Companies that THINK they are buying one thing are getting another without ever knowing. It's a big problem. Something needs to be done and I think the gov has started. I think.

Rob Spiegel
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Re: Capacitors
Rob Spiegel   11/14/2012 9:22:29 PM
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Cadman-LT, counterfeit parts take a number of shapes. Generally, they are inferior. Many of them are stripped from electronic products that get shipped from the U.S. to developing countries. Poor families, strip out the components and the parts are flushed back into circulation. This also causes health hazards for the familites stripping the parts.

Ratan1
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Iron
Need to Apply Statistics
Ratan1   11/2/2012 11:58:27 AM
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Get the dimension of the speakers, both mean and standard deviation, and makes sure that the inside dimension of the cabinet is at least mean + 3 sigma. This will fix the root cause of the problem.

Ratsky
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Real root cause!
Ratsky   11/29/2012 4:56:25 PM
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For a number of years, I worked for a company whose top management and founders came out of the aerospace industry.  The president was a former "jet jockey" test pilot.  He had a simple rule that saved us all a lot of grief:  "Glue always fails eventually.  Never use glue where its failure causes a product defect."

Tool_maker
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Platinum
What about the help?
Tool_maker   12/12/2012 12:52:44 PM
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  It seems to me that the worker who bent the speakers to get them in place is getting a free pass here. I am curious as to the company attitude that allowed the worker to think this was an acceptable fit. If it doesn't fit, it doesn't fit: end of story. Put both aside for rework and move on. But it must have been the case that the attitude was, "Make it fit." Not a good thing.

  I also agree with the general distrust of glue. Eventually it will fail, but there are many items out there that are glued assemblys and last for years. But I want screws, welds, rivets or any of a multitude of historically proven methods of fastening. 

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