News

Garage Door Sales

Thursday, June 22nd, 2017 at 4:17 pm by Dan Musick

DDM Garage Doors no longer sells garage doors outside of the Chicagoland area. In the past we built wood crates for shipping garage doors over the road. We recently stopped doing this because the $500-$1,000 freight costs were often as much as the price of the door itself.

We also tried shipping doors through the Amarr dealer network; the closest regional Amarr warehouse would deliver doors directly to our customers. We stopped doing that due to frequent complications regarding door features, lead time, and shipping details.

If you are still interested in purchasing a door, and if you are outside the Chicagoland area, we suggest you try a local Lowes, Menards or Home Depot. Their prices are reasonable, but you may have to wait a few weeks for the order. Sometimes local mom-and-pop stores have the door you need at even better prices. There are also a few companies that sell doors on line.

Sometimes it’s better to bite the bullet and hire a professional installer. From past experience we have found that an installing company can better size your opening and provide the best door for your application. I’ve never been impressed with the advice I’ve gotten at home centers.

 

When are leaf bumpers and push down bumper springs necessary?

Friday, June 2nd, 2017 at 11:48 am by Andrew Koetters

Leaf bumpers or push down bumper springs are recommended for use on residential standard lift applications when using a jackshaft opener, as well as certain commercial applications.

Normally, if space allows, a standard overhead rail type opener is used for standard lift systems. These openers pull/push on the door directly to raise and lower it. If more overhead space is required, or you desire a nice “clean” look, a jackshaft opener can be used. This type of opener mounts on the header, and raises/lowers the door by driving the torsion spring shaft directly. For residential systems, we recommend the Liftmaster 8500.  This opener is designed and mainly used on high lift assemblies, but with the proper steps, can be used on a standard lift system.

When using this opener with standard lift tracks, the spring bumpers are necessary to ensure safe operation. This is because jackshaft openers rely on the door weight to keep tension on the cable.  These bumpers mount to the back of the horizontal tracks and provide forward/downward force on the door when it is in the horizontal tracks.

 

If the door is in the up position with minimal weight pulling down, there is a slight risk of the opener turning the shaft, the door not moving, and the cable unwinding off the drum. There is then nothing to stop the door from crashing to the floor and causing damage or injury to anything or anyone in its way. To counter this, the bumpers provide constant force pushing the door down from the back, which should keep the cable taught.

The recommend Liftmaster 8500 opener comes standard with a cable tension monitor for safety. A common question we get from customers is whether or not the cable tension monitor on the jackshaft will be sufficient to stop the opener, and hold the door if the cables were to go slack. Generally, this should work, but we do not recommend relying on it 100%. The spring bumpers are relatively cheap insurance to guarantee that the door will work properly and safely.

If you are interested in using a jackshaft operator on your standard lift door, we suggest using these spring bumpers in order to prevent property damage or serious injury.

 

Clopay Pinchproof – The Downside to Unique Hardware

Friday, May 26th, 2017 at 1:00 pm by Andrew Koetters

Just recently, Clopay stopped manufacturing the hinges for their specially designed Pinch Proof doors. One of the most common models to use Pinch Proof hinges is the model 150S (commonly found in the western U.S.). These pinch proof doors were originally developed in the 1980’s to protect against damaging fingers and other foreign objects that could potentially get caught between the door sections. Although some manufacturers had already developed other “Pinch-Proof-type” options, the designers of the Clopay Pinch Proof system sought to create a simpler design that both professional and DIY installers and repairmen can understand. Despite the attempt to develop an option that was both safe and fairly intuitive, these hinges were constructed with cheap steel and have been known to break at a high rate. This is not necessarily the reason why Clopay manufacturers discontinued the part, but it is certainly a disadvantage of the design. Here is a sampling of the Pinchproof hardware:

 

If you have a Pinch Proof door and one of your hinges has broken, you are left with only a few options:

  1. You may be able to find a company that still has these hinges in stock. At DDM, we still have a number of #0 and #4 Pinch Proof hinges in stock, but we no longer have any #1, #2, or #3 hinges. The pins and covers for these hinges are also still available on our website. Because of the nature of the Pinch Proof system, you cannot simply apply one of the standard hinges that we offer. Instead of placing the pivot point directly at the point of separation between the panels, the pivot point of the Pinch Proof hinges are below the point of separation between panels. Refer to the patent drawings below.
  2. You may be able to have a local metal fabrication or machine shop repair the hinge. It may work for a short time, but it will only function as a temporary repair.
  3. Regardless of your initial course of action, you will ultimately be faced with the third option: to purchase a new door. We recommend choosing a door that is designed for and uses standard hardware.

 


Sources below*


While specially manufactured systems like the Clopay Pinch Proof doors may provide a number of benefits for customers, this does not make them inherently “better” than doors with standard hardware. Seeing as the parts for these specially designed systems are often not interchangeable with standard hardware, the manufacturers of such parts offer very few options for customers once the parts are discontinued. Although DDM Garage Doors sells specially manufactured parts such as the Clopay Pinchproof, Wayne Dalton, and Amarr hardware, we generally recommend using systems which have standard hardware.

 

 

*United States Patent and Trademark Office – U.S. Patent 6,006,817

http://pdfpiw.uspto.gov/.piw?PageNum=5&docid=06006817&IDKey=EEC703709CED&HomeUrl=http%3A%2F%2Fpatft.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect2%3DPTO1%2526Sect2%3DHITOFF%2526p%3D1%2526u%3D%2Fnetahtml%2FPTO%2Fsearch-bool.html%2526r%3D1%2526f%3DG%2526l%3D50%2526d%3DPALL%2526S1%3D6006817.PN.%2526OS%3DPN%2F6006817%2526RS%3DPN%2F6006817

http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=/netahtml/PTO/search-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN/6006817

 

Click Farms

Tuesday, November 15th, 2016 at 1:09 pm by Dan Musick

click-farms

Over the past year, my company—and many others—have been the victims of a disturbing business competition strategy being used by certain disreputable companies, whose aim is to falsely cast their targeted competitors as being “disliked” on public media sites. The goal of this unethical strategy is to harm the target’s online reputation, which has become increasingly vital in today’s technology-driven environment. Unfortunately, this-so called “Click Farm” trend is on the rise. I wanted to write this article to show how you can recognize and avoid sites that use click farms to influence your buying.

What are Click Farms?
“Click farms” are a type of deceptive practice done by people who are trying to gain more followers on Twitter, “likes” on Facebook, artificial views on YouTube, or another form of website in order to gain a higher ranking on a search engine when consumers search for their posts online. Online traffic to the page is simulated to make it appear like actual customers or viewers are clicking on links. While real people are clicking links, they are not customers but rather people paid to do nothing but click on links, browse on the page for a little while, and then move on to the next link using fake profiles that appear to be from different geographical locations than where the paid clicker lives. (2) These click farms do not use the businesses’ services or products; they do not know anything about the services or products; and in fact they may be thousands of miles away from the businesses they claim to like or know about.

Boosting traffic to their particular page serves to benefit no one but the person employing the click farms, in getting more people to their page to buy more products, but does nothing to help the customer. It does not help you to find the best products, nor does it guarantee that they will not cheat you into buying products that will not suit your needs. At DDM we promise to assist you in finding the parts that will fit perfectly to you particular garage door, and we will not talk you into buying anything that will not work for you or that you do not need.

How Click Farms harm business.
Importantly, Click Farms not only harm the target business, but they also harm the businesses that are using them. The reason is that they create an inflated idea of what products you, the customer, actually need. It leads consumers to believe that certain products may be more desirable than others, and leads businesses into stocking more of one product and not another, due to the (wrong) perception based upon the faulty media. This can lead to customers being unhappy because the products they need may not be there because of inflated demand for other products, as well as price discrepancies due to a perceived demand not panning out for the businesses.

Click Farms don’t even help the people getting paid to do it. While you as the customer are not being helped by click farming, the people hired to do the Click Farming are not benefiting in any way either. They are paid measly wages in order to sit at a screen clicking for hours to make almost no money per day. By purchasing from companies, or clicking on links to these companies that buy these services, you, the customer, are leading companies to believe that this type of advertising is working, causing them to continue to pay these click farming companies for their services, and having the workers there continue to be paid almost nothing for their work.

What can be done?
When it comes to Click Farming, knowledge is power! Luckily, there are ways that can help you to spot this kind of shady behavior in order to protect yourself from scam artists. Below are ways to spot Click Farming on different social media mediums, such as Facebook, Twitter, and YouTube. While not all social media sites are covered, the rules discussed can also be taken as a general rule for other sites as well.

How to Spot Possible Click Farm Activity.
Some of this malicious activity is easy to spot, such as comments on YouTube videos. If the comments sound like inane nonsense, then the comments more than likely came from a click farms, or at the very least from a fake profile. Capitalized letters also indicate a fake profile. Comments that don’t fit in with the content of the video should also be suspect.

Another way to discover this behavior is to check the statistics of a given video. To do this, simply click on the “More” tab under the video.

click-more

Next, click the “Statistics” option.

click-statistics

On most videos the cumulative number of views, which is what Google sees, look perfectly normal.

click-daily

If you look on other videos, and if you click the “Daily” option tab you may find a different story.

synthetic-views

As you can see on this YouTube video, there are only two specific periods of time that show a sharp and dramatic increase in the number of views accumulated, while the rest of the time there is a fairly steady stream of only 50-100 views per day. This is an easy way to spot click farming, as there is no logical way that over two short time periods tens of thousands of people watched the video every day, only to have views dramatically trail off yet again to only 50-100 per day. YouTube, Google and other pages have been clearly manipulated.

A view stream should look much more like that in the image below from our “How to Replace Garage Door Torsion Springs” video.

normal-views

At its peak when Google showcased it as the lead video on a search of garage door springs, the views on our video never reached 1500 per day rather than the more than 25,000 daily views from artificial click farms views. Notice, also, the clear day to day fluctuations over the history of views.

Another way competitors interfere with businesses is by buying dislikes on videos in order to drive people to look elsewhere to buy parts. For example our “How to Replace Garage Door Torsion Springs” video shows 1,103 thumbs down in the image below. A disproportionate number of dislikes also lowers YouTube and Google rankings. In the image above notice the decline in late 2014 and early 2015. This decline correlates with the thumbs down views on our YouTube video and the synthetic views on competitors’ videos. This unfairly hurt our spring sales proportionately.

click-farms-dislikes

 

Notice below an increase in spikes on our video which looks fishy even to an unsophisticated user. There were 977 dislikes posted on two short time periods in late 2014 and early 2015.

ddm-dislikes-graph

As you can see below 366 of the thumbs down came from click farms in Vietnam.

ddm-dislikes-vietnam

And you will also see below that 517 came from Russia.

.ddm-dislikes-russia

An additional 50 thumbs down came from Moldolvia, India and Thailand. In these developing countries click farming has been seen for years as a semi-respectable way to make a living.

ddm-dislikes-moldovia-india-thailand

The countries above are known for being hot spots for click farms. Only 10 of the 977 dislikes during this time period came from the U.S. and Canada, showing that this video must be helpful in English-speaking countries, and that it is generally well received.

Because of the vicious nature of the YouTube environment we have re-posted this video, our “How to Measure Garage Door Torsion Springs” video, and our other better videos on our own servers.

Click Farming occurs on Facebook and Twitter too.
Facebook and Twitter are less easy to see, but are still harmful and can appear to be much the same. Similar innate comments that don’t often make much sense with the post they are attached to can be ways to spot these kinds of activity. If something seems too good to be true, seems like an ad, or looks like it was typed out by someone who doesn’t know how to use a keyboard, then it probably is the result of click, or “like” farming. They are simply searching for likes for their own malicious purposes, and are not attempting to alert you to anything that you should be paying attention to.

Twitter click farmers operate in the same way, getting you to click links to things you don’t care about by making them look interesting or grabbing your attention in some way. Even if a page seems like something you like or want to pay attention to, be sure to keep up with the page because it may be changed to suit whatever the creator’s purposes are at the time, and they may use your likes of their posts to advertise their products that you may never have liked in the first place.
With friend requests, be sure to be on the lookout for people who you don’t recognize, and have few friends on their profile, and quite possibly no mutual friends with you. Their biographical information will be almost nothing, even after becoming friends with the person, leading you to wonder, who is this? And why am I friends with them? These are more than likely fake accounts created by click farmers that are sold to other companies in order to boost a social media presence. The same goes for Twitter; if they don’t have many followers, and their followers are no one you know, or very few people you know, they are more than likely a fake profile.

A Call to Arms: Avoid companies that hire click farms!
The best way to find the best products and the best sellers of those products is to look for sellers who don’t use click farming to generate more apparent activity on their pages and videos. Sellers who are honestly seeking to help you, the customer, find what you need know don’t need to use click farming in order to please customers. “Like” farming may not even take you to what you are looking for, but may redirect you many times to pages that don’t fit what you are looking for. You should avoid any of this type of pages, videos, or posts because they do not have your best interest in mind. Remember also, that companies who use shady tactics to influence your buying will usually treat you with shady gimmicks such as upselling.

Buying from ethical companies also benefits you. By allowing the companies which desire to help you find the product that you are looking for actually sell you products that suit your needs, you support companies with goals beyond increasing their bottom line. According to The Guardian’s Charles Arthur, “31% of consumers will check ratings and reviews, including likes and Twitter followers, before they choose to buy something.” In checking these ratings, be sure to look out for the pieces of information that can help you to tell whether it is a fake rating, or a real review from a customer. As with YouTube comments, if there is innate nonsense in the review, then it is more than likely fake and not produced by a real person. Knowing how to find these signals is very helpful in determining whether or not you will want to buy a product from the particular company. (1)

Companies who employ click farms are also hurt because once customers hear about click farms being used, they become skeptical of all numbers of views or likes if they seem high for whatever reason. Or, seeing the high count of views or likes, the customer may be drawn to the page without even thinking about whether or not it is helpful for their needs. (2)

If you’re a company looking to hire a professional who has a broad knowledge of social media, and have judged this by the amount of Facebook friends, Twitter followers, and Instagram followers the person has, then you could be misled as well. They may also be fake, bought so that you, the employer, would be more likely to hire them because of their experience with social media. “If those numbers are fake, you’re wasting money and probably hiring the wrong person” (2). This causes you to be “losing the race for talent,” as Sherman puts it, putting you behind your competitors, and creating a problem for your business.

Being aware of this can help you when buying products, hiring for your business, or just in the general scope of being on social media. Exercising care and caution in picking who to purchase from, and interact with on social media can help you protect yourself from scammers and others seeking to rip you off.

Citations:
1. Arthur, Charles. “How Low-paid Workers at ‘click Farms’ Create Appearance of Online Popularity.” The Guardian. Guardian News and Media, 02 Aug. 2013. Web. 18 July 2016.
2. Sherman, Erik. “4 Ways Click Farms Screw Your Business.” Inc.com. Inc., 10 Jan. 2014. Web. 18 July 2016.

High Lift Assembly Modifications

Monday, December 21st, 2015 at 9:41 am by Dan Musick

Since we first posted our custom High Lift Garage Door Conversion instructions several years ago, we have noticed a few things that need to be improved.

One was the alignment of the horizontal and vertical angles in step 7.11.

bracket2

This created a problem with the fitting of the end bearing plate in step 7.21. In our instructions we show cutting the angle to get the plate to fit.

high-lift-conversion-094

A second problem that plagued me for several years were our assembly instructions. We originally showed the extra work of sliding the brackets along the vertical high lift angle at the end. These instructions also lacked detail, and the step-by-step procedure needed to be honed.

The solution for both problems was to redo the instructions. In the new tutorial we show how to assemble the components starting from from the top – assembling the vertical and horizontal angle first – and then working your way down to the track extension. This change is included in the new high lift track assembly instructions we posted this fall.

high-lift-track-in-house-assembly-14

An added advantage to this is that it reduces the possibility of the junction bolt coming loose and the door losing its level. It probably also cut the assembly time in half for our customers.

On some tracks the horizontal track angles are rotated 90 degrees. The assembly for these is slightly different.

alternate-high-lift-angle

A third change we expect to make in the coming months is the angle for cutting the ends of the vertical tracks extensions. In our tutorial we specify four degrees, which works for most doors. In our Garage Door High Lift and Vertical Lift Inquiry the information you now enter allows our new program to specify the angle for cutting the ends of the tracks. If you see a note in your high lift kit or in your correspondence regarding the angle to cut your tracks, use this angle and not the four inches specified in our program.

A fourth change is to show pictures of double spring installations as we show on our garage door torsion spring replacement page. Our original program shows how to install a high lift with only one spring. We also want to show what a four spring setup looks like for the heavier doors.

A fifth change we want to show is how to install hardware with a shaft coupler. When converting to high lift, if  you don’t have a shaft, and if one is not available locally, we can send two shorter shafts with an extra spring anchor bracket and coupler.

shaft-coupler

This has also worked with 18′ wide doors where we sent, by FedEx, two 8’9″ shafts, one 2′ shaft for the middle, two couplers, and two spring anchor bracket kits.

The sixth change has to do with heavier springs on high lift doors. Our program is designed to spec idler support brackets for torsion springs that weigh over 20 pounds. These are normally installed just beyond the winding cone of each spring after it is wound. The formula for determining placement is (#turns on spring X wire size) + 2.” In most cases the bracket can be moved a foot or so to align with a stud.

shaft-support

A last change has to do with special applications where a customer needs to convert from double low headroom tracks to high lift. This may occur when a loft above the door is removed, or when a low headroom door is moved from one location to another.

low-headroom-06-double-tracks-rivets-300x201

In the coming months we hope to incorporate these changes into the revised high lift tutorial. Your patience is appreciated.

Rough Edges on High Lift Drums

Monday, November 16th, 2015 at 12:24 pm by Dan Musick

In recent months we have received emails from customers who installed high lift kits, and now one of their cables is fraying or unraveling.

IMG_0290

This appears to be a problem with the foundry where the OMI 4-54 HL LD cable drums are made. The joints of the molds leave rough edges on the drums. These rough edges need to be smoothed, but the foundry is not consistent in grinding the edges.

Rough Drum Edges

In recent months we started grinding all these drums in our shop.

If you purchased one of our kits in the last two years, and if you have a high lift cable that is beginning to fray or to unravel, we will provide new cables. You can file the rough edges on the drums, which would be less work, or, if you prefer, we will provide new drums as well. There will be no charge for the parts or for shipping. Please provide your order number, if available. Otherwise, we can search our invoices by your name.

I apologize for any inconvenience resulting from this quality issue.

Common High Lift Problems

Thursday, November 12th, 2015 at 12:22 pm by Dan Musick

Without first seeking professional help, the most common problem do-it-yourselfers encounter when adding vertical track and raising their garage doors a foot or more is that the door doesn’t balance.

In order to get the door to work at all, longer cables need to be installed. The installer will usually know to do that.

This is typically what happens, for example, after a do-it-yourselfer raises the horizontal tracks and torsion assembly on a seven foot high 200 pound door by two feet.

The springs on most seven foot high doors are wound 7 1/2 turns. If you wind your springs the same number of turns after raising the horizontal tracks two feet, the door will stay on the floor by itself when closed. However, as you raise the door, the higher you go the heavier the door gets. Except for the first foot or so the door will not stay open by itself.

Raising the tracks two feet requires about two extra turns of spring tension to hold the door open when raised. If you wind the springs 9 1/2 turns, the door will stay open, but as you close the door, the lower you go, the harder it gets to pull the door down. If you release the door in the closed position it will shoot up like a rocket.

If the springs are wound 8 1/2 turns, the door will balance about midway. The door won’t stay up and it won’t stay down, but it will stay half way.

In addition to not balancing the door, the extra turn or two on the springs reduces the cycle life by as much as two thirds.

One solution is to spring the door for nine feet of door height. The longer a spring is the less it pulls. The springs need to be longer so they lift 200 pounds with 9 1/2 turns when the door is closed, and yet, when the door is open nine feet, or less, there must be enough turns on the springs to support the door weight.

This solution will work with lighter doors and with doors where the tracks are raised only a foot. The door will not balance correctly, but it may work reasonably well. The springs can be wound to hold the door open and to allow the door to stay closed by itself.

The main problem arises as the door is lifted. Because the door does not immediately transfer weight to the horizontal tracks, the lifting weight of the door will increase for the first two feet or so of rise. On heavier doors this could trigger the sensors and shut off the openers.

The best solution, however, is do a complete high lift conversion. This will require new cables, drums and springs.

DR-400-54

High lift counterbalance is complex. A detailed explanation appears on our page titled “How Vertical-Lift and High-Lift Garage Doors Work.

 

 

New DIY Instructions App for Cell Phones

Thursday, May 28th, 2015 at 11:20 am by Dan Musick

screenshot1

We’re happy to introduce our new app available for $1.00. It contains a wealth of technical information on garage door springs and spring conversions, garage door and opener maintenance and repairs, high lift conversions, low headroom solutions, weather seals, and dock leveler repairs.

One of our software developers, Nate Rupsis, recently re-organized our tutorials library. Afterward, and in keeping with the times, he formatted the page as an app to fit the more popular smart phones

.nate-rupsis

This app has grown out of my 36 years in the garage door business.

I initially worked at the Overhead Door Company in Elk Grove Village, IL, the largest door business in the industry. In January of 1979 I began as a service man for the owners, Harold Tonnesen and Jim Weeks. In subsequent years I built an audio visual training library while serving as training coordinator for the company. During that time the company left the OHD franchise and changed their name to Door Systems. The owners also opened Northwest Door, a new sectional door manufacturing facility in Elgin, IL, where I developed training and manufacturing support materials.

In the eighties I developed a company with three divisions: (1) The sale, installation and repair of residential and industrial garage doors doors and operators, (2) The sale of garage door hardware, and (3) Training for building engineers and facilities maintenance personnel to repair their doors and operators.

In the early 90’s I sold Dortrak, the installation and repair company, and kept the other two divisions. These weren’t generating enough income to feed and shelter my family so I went to work for Harold Poling at Area Door in Elgin, IL for about 15 years. He agreed to let me grow my own business on the side as long as I didn’t work in his service area, which I honored.

While working there I grew the service and installation business. My older son, Erich, loved computers and the internet and in 1997 he developed and posted our website. In 1998 we began posting online repair instructions for various types of overhead sectional garage doors and openers.

In the early years of the Web we didn’t earn enough to justify paying to post the site. We joked about being a .org. One of our major stockholders suggested I close the business. We survived the year 2000 dot-com collapse – little invested, little lost.

From there the internet parts business grew with the installation and service business, and several years ago I left Area Door to work full time in this business.

Earlier this year we sold the installation and service company to Matt’s Garage Doors. He’s doing better with that part of the business than I ever did.

Now, as DDM Garage Doors, Inc. we continue to provide garage doors, parts and hands-on training. As DDM Web Services, Inc. we develop tutorials and software for the garage door industry, for building engineers and facilities maintenance personnel, and for the DIY market.

These programs have also inspired many entrepreneurs to start their own garage door repair companies, and for over a decade garage door repair technicians have benefited from our free online instructions and software.

God has blessed me with work that I love. I wish the same for everyone who works on all the different types of garage doors and openers. Life’s too short to endure work you hate. A friend of mine in my early years at Wheaton College advised, “Determine what you enjoy doing, and find someone to pay you to do it.”

Blessings!

How Mechanical Dock Levelers Work – Preview

Thursday, May 14th, 2015 at 7:29 pm by Dan Musick

I’ve been working in the garage door business for over 36 years. It wasn’t until a few years ago that one of my employees explained to me how mechanical dock levelers work. It’s taken many months, many videos, many graphics and a lot of animation, but in early July we expect to be posting the completed video on YouTube so professional door technicians and other tradesmen can understand how they work. The outline below is a shadow of what we expect to be our best video yet.

Introduction
Dock Leveler Springs
Extension Spring Systems
Compression Spring Systems
Hold Down Systems
Ratchet
Gear
Clutch
Lip Systems
Counterbalance Components
Snubbing assembly
Lowering Mechanisms
Safety Legs

Here it is. Just click the leveler.

How-Mechanical-Dock-Levelers-Work

PowerMaster Operators

Thursday, April 23rd, 2015 at 11:10 am by Dan Musick

V.E. Power Door, manufacturer of the PowerMaster brand of sectional door, rolling door, and sliding gate operators, was established by its founder, Philip Lanzarone, in October of 1969. From its Long Island facility the company was originally created to service North American Door, but in succeeding decades V.E. Power Door has provided products for the garage door and gate industry throughout the world through its own distribution network, including John Greene Corporation.

Those of us who have installed and serviced industrial operators over several decades attest to the consistent reliability and superior quality of the PowerMaster brand.

This is our preferred choice of garage door operators.