I am the R&D manager, with 22 years of electronics experience, at a Toronto-based printed circuit board fabrication firm. A buddy here at work came to me to look at a hairdryer his wife bought. They had returned three of the same unit over several months, and the store would not replace it again, saying they would have to deal with the manufacturer.
He wanted to find out whether his wife was just abusing the cord by tightly wrapping it up around the unit every time she finished with it. He was convinced his repeatedly ignored assertion that she was causing the cord to break by her abuse had to be verified before he say "I told you so."
I said I would have a look. Sure enough, the cord had a bad section somewhere near the anti-kink device at the base of the handle. After removing the bad section of cord and re-soldering the ends, I noticed that the internal cord restraint/stress relief structure, which was molded into the inside handle, would not accept the cord and the anti-kink device without a great deal of effort.
It was then that I noticed the cord was run through the cord restraint counter-clockwise, which caused the two parts to interfere with each other. This put enormous stress on the cord trapped between the two features. If the cord was fed through in a clockwise direction, there was plenty of room for everything.
The restraint is actually asymmetrical, leaving more room on the right side for the exit of the cord on its way further up the handle to the soldering points. The left side almost touches the anti-kink device’s flanges that secure it in the handle. This leaves almost no room for the cord.
This is a unnecessarily difficult chore for the folks in assembly, to boot. Sadly, the design was fine, but the assembly was executed incorrectly, causing premature failure of the cord. I’ll bet all three of the units were assembled in the same way, ultimately turning a well-thought-out design into a poor product.
This entry was submitted by John Hilyer and edited by Rob Spiegel.
Tell us your experiences with Monkey-designed products. Send stories to Rob Spiegel for Made by Monkeys.
It may be possible that the cord incorrectly on a certain few of these units. It may have ben a situation that the main operator on the station had the afternoon off and the relief operator was not sure how to assemble the cord and made a few incorrectly, but these units went to the market anyway. It would be interesting to see if a dryer purchased somewhere else with a different produciton date would have the same assembly method.
I've noticed the same problem not only with cables, but with the connectors, too, on most consumer electronics equipment such as laptop AC power supplies and various types of displays. Especially for expensive display connectors, we wish we could find replacement connectors to save money, but will probably have to replace the entire cable assembly.
Amclaussen wrote: "At least, a few appliances have cord reels buit into the body of the appliance, which if properly designed and implemmented, will prolong the cord life at least an order of magnitude."
Ahh, but these are subject to a different problem. When done using the appliance, the user tugs the cord enough to releasethe rachet pawl, then releases it. The reel winds with accelerating speed (angular velocity ramps up and effective reel diameter increases as the cord fills the spool) until it is suddenly stopped as the plug hits the housing. This is a great mechanical way to rip the plug from the end of the cord--even better than yanking the cord to remove the plug from the wall outlet.
I had to instruct my late wife to hold the plug and let it slowly feed into the canister vacuum cleaner.
Amclaussen also wrote"If an internal cord reel is not feasible, the designer should at least design the apparauts with the best arrangement of "hooks" to store the cord around the apparatus together with a proper cord attachment and orientation to the body that avoids sharp folds or creases, while providing a neat and practical way to store the cord between uses."
Ahh, yes. These are used on upright vacuum cleaners. Often the anchor point of the cord is not aligned with the hook loop, so there's a sharp cord bend by design. A good feature is that the top hook swivels so you don't need to unwind the cord a loop at a time--just swivel the hook and pull all the cord off. Most folks don't realize that you should wind the cord in a figure 8, crossing over center with every turm. This avoids putting twists in the cord, so that when you drop it off, it falls uncoiled.
I SECOND that emotion! This is especially true in the present time since "smart" phones & EVF digital cameras proliferate to the nth degree. In so many instances of these blogs, while it may be fundamentally clear to the author in describing the problem / fix, when translated into text, there is a lack of clarity. Certain small details are almost always ommitted, but they hold the key to a complete understanding of the situation. There should be an easy method to solve this dilemma.
Rob, this really is a case where a picture is worth 1000 words, This problem would have been much easier to visualize had you posted a few photos of the open product.
I'm sure the author took photos, just so his buddy could show them to his wife.
Cables have always been a problem. They are probablt the most abused item on any device using electricity.
I have miles of somewhat expensive audio cable. The only way that I wrap these cables is the "so called" Firemans wrap, which prevents putting a twist into the cable. Not only does this reduce the damage, but it also means that the cable will lay flat on the ground without a twist in them. I have had to replair very few cables since I started this.
Cables on corded tools and appliances take the most abuse. People wrap them tight without any concern about the tight corners. However, this is more of a problem today than it was 20 years ago. The cable jackets are generally less pliable than they used to be. Vinyl jackets cause the most trouble as when they get cool, they stiffen up and crack. Where they crack is usually where the conductors break. I have repaired many curling irons and hair dryers for my daughters and almost without fail, the problem stems from where the vinyl jacket has become damaged. I started replacing the cable with HEATER cord and found that the cables lasted much longer. Still, proper wrapping would make the cables last much longer.
However, power supply DC cables for laptops seem to fail all the time these days. HP for one has decided that a doubly shielded cable is the answer. These cables fail within a year or so. Even if the owner is careful with how the cables are wrapped, the shields tend to break, or, the inner core, which is about 22Ga snaps. The connectors for the cable are not available at any electronics supplier that I have found, so either the suppli must be replaced, or the connector cut off, stripped of it's connector body, and the wires re-connected to the actual connector. I use a RUBBER BNC slip on strain releast to protect the electrical connections from further damage.
I've seen all kinds of cords fail sooner than later in many kinds of devices.
One thing they all had in common is the Lack of Design/Bad Design of the cord entry to the device or the lack of means to properly store the cord, which causes the cord damage, more than dumb people pulling the cord to disconnect it. At least, a few appliances have cord reels buit into the body of the appliance, which if properly designed and implemmented, will prolong the cord life at least an order of magnitude. If an internal cord reel is not feasible, the designer should at least design the apparauts with the best arrangement of "hooks" to store the cord around the apparatus together with a proper cord attachment and orientation to the body that avoids sharp folds or creases, while providing a neat and practical way to store the cord between uses. This is a matter not only of proper, ergonomic design, but affects safety too. Amclaussen.
I share your frustration with people's behavior. I worked at a shop where the other technicians liked to wrap the test leads tightly around the test meter, causing a sharp bend at the plug-in connector. Every time I used the meter I cautioned them they were going to break the leads and get a false no-voltage reading. I always tested a known hot first when I used that meter, and one day that proved one of the test leads had broken. Even after that, the other technicians still wrapped the leads tightly around the meter.
From Dell / Intel® New Paradigms in Design Work Scott Hamilton, vertical market strategist for Dell Precision workstations, 5/2/2013 3
Early in my career, I worked as a draftsman and remember the days of drawing on vellum with numbered pencils and Mylar with plastic lead. This was a fun experience in the sense that I ...
I've been using workstations for more than 10 years and love finding ways to get more performance from my system. With demanding professional applications that require more power each ...
A lasting memory from my first job as an engineer in an auto assembly plant is standing on hard concrete at six in the morning, vending-machine coffee clutched in hand, listening to ...
A quick look into the merger of two powerhouse 3D printing OEMs and the new leader in rapid prototyping solutions, Stratasys. The industrial revolution is now led by 3D printing and engineers are given the opportunity to fully maximize their design capabilities, reduce their time-to-market and functionally test prototypes cheaper, faster and easier. Bruce Bradshaw, Director of Marketing in North America, will explore the large product offering and variety of materials that will help CAD designers articulate their product design with actual, physical prototypes. This broadcast will dive deep into technical information including application specific stories from real world customers and their experiences with 3D printing. 3D Printing is
To save this item to your list of favorite Design News content so you can find it later in your Profile page, click the "Save It" button next to the item.
If you found this interesting or useful, please use the links to the services below to share it with other readers. You will need a free account with each service to share an item via that service.
Tweet This
6 
