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Gadget Freak
Gadget Freak Case #215: Automating the Doggie Door
6/5/2012

Les Kelly's remote can control your pet flap opener from the couch or bed when your pets need to go in or out.
Les Kelly's remote can control your pet flap opener from the couch or bed when your pets need to go in or out.

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NadineJ
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Platinum
Very cool video
NadineJ   6/5/2012 1:10:12 PM
I like the progression.  It works very well.  I'd love to see the next step maybe targeting cat owners...a door that unlocks with a signal from a receiver on the collar and relocks automatically once the collar is out of range.  But, with an option to turn off the signal to keep the pet inside.

From a users point of view, something that could fit in an open window would be commercially popular for cat owners.

Jennifer Campbell
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Gold
Re: Very cool video
Jennifer Campbell   6/5/2012 3:36:19 PM
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Sounds like a great project NadineJ! Get to work and if we like the end result, we'll feature it on designnews.com, possibly in our print edition, and we'll send you a check for $500! What have you got to lose?

NadineJ
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Re: Very cool video
NadineJ   6/5/2012 4:44:57 PM
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OK.  It's on my list of future projects but that scroll is really long!

@novahokie(Les)-the doors on the market are big projects.  Here in San Francisco, there are thousands of renters who have pets.  Landlords wouldn't tolerate what's needed to install one of the current doors on the market.  What I love about your door is that it's small, simple and easy to make. 

Years ago, I had an outdoor cat who roamed between 1-3am and hunted from 5-7am.  I don't know what he was up to while I was at work.  I left the window cracked open for him to get to the backyard anytime.  For security, I put a window lock that would hold it open only 6 inches.  Rain or shine, the window was wide open.

A door, like yours, that could fit in the window (similar to the aftermarket adjustable screens that many use in apartments) with a door that locked if the cat wasn't nearby would have been great.  No majour construction in the rental unit, no rain in living room and a happy cat that could come and go as he pleased.

Ok...it just moved up a bit on my list....

novahokie
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Iron
Re: Very cool video
novahokie   6/5/2012 5:18:30 PM
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Great idea Nadine!  The original version of my invention is going to be available on the market later this summer under the name EasyOut.  It is going to be marketed as an add-on product for wire crates, but I modified the standard version of it very easily to open common bolt-action latches like you see on cabinets, and I use it every night to open a large wooden door on a pen in my basement where our dog eats while my wife and I eat dinner upstairs.  One push and she comes running up the stairs and joins us without me ever leaving the recliner I eat dinner in.  I agree with you that its main appeal is that it's a simple, cheap, and modular way to open any latch that can be opened by a simple lateral translation - ie it can't twist anything, etc. - by pressing a remote control button.  I even used to have a version where I used the same remote that I use for the TV.  I'm also working on getting the built-in remote pre-installed by GM in my Camaro's dashboard (normally used for garage doors) to open it, so I don't need the separate remote that will come with the product to let out our dog(s) when I'm driving into the driveway.  We're also looking into activating it via a smartphone app like you see advertised now for other home automation stuff, and/or using a timer.  A driving factor for the smartphone app or other PC control would be to let your pet in from the yard at work if a storm came up suddenly similar to what you mentioned, or out to pee if you realize you're going to be late getting home due to work or traffic, etc.  There is also interest from folks who raise chickens, as a way to let them all out of their coops into their yard automatically at a given time each morning.  Also dog kennels/etc. to remotely open specific cages from a large bank of them, etc.  My personal favorite benefit is to release your dog from an outside kennel to come into the house for the evening if it's raining, cold, or snowing, without going outside.  It could also be set up to be triggered by the tags worn by the pet for them to go in/out at their discretion.  I have patents that mention all this stuff as possibilities, it's just taking me a while to develop them all!  :-)

Barney48
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Iron
Re: Very cool video
Barney48   6/5/2012 6:01:32 PM
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I am very much interested in something similar for opening and closing the chicken run door for my chicken coop.  It would need to do more than just unlatch/latch, but actually open/shut the door at predetermined times.  I would think there would be a lot of interest in this as well as the Doggie Door.

novahokie
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Iron
Re: Very cool video
novahokie   6/5/2012 6:18:03 PM
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Yes, we've heard from a couple of folks who have chickens.... apparently the organic chicken market is pretty vibrant!  It's very easy to train a dog to nudge open any door when they hear the click of the opener unlatch it, especially after they've gotten used to listening for it - which only takes a couple of times.  I haven't tested with any chickens yet, but the other chicken farmers tell me chickens would be able to open a light door and come out.  Shutting doors later is another topic I've thought about a lot and have some ideas about, but haven't built any prototypes for yet because that aspect is more dependent on the particular application - i.e. what type of animal, what type of door, how/when do you want it to close, will the animal go back in on their own or not, etc.  For example for applications where the animal would naturally go back in on their own during the day you could just spring load the door they come out in the morning such that it would shut after they leave their coop in the morning, lock it remotely with 1 of my boxes equipped with a "push" solenoid inside it instead of its normal "pull" type that pulls open the latches, or use a combination push/pull solenoid (they're a little more expensive but available) and then let the animals return inside in the evenings through a 2nd flap/etc. with a simple setup that allows them to pass through to go back into the coop/pen/etc. in the one direction but not the other.  For example a very light spring-loaded pivoting flap.

novahokie
User Rank
Iron
Re: Very cool video
novahokie   6/5/2012 6:22:22 PM
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You could also create another device that pivots/opens a door radially instead of my current device that only provides a lateral translation for the latch, if it was necessary to open/close a pivoting door.... or use a guillotine or sliding door and keep the current design because a sliding door would only require lateral motion.  In other words, my current device would pull open and later shut the door.  The challenge would be getting solenoids strong enough and with long enough travel to do that if you needed to stick with battery-powered operation (which was a major challenge in my development)... however, if you were free to use AC power like I had for my prototype then it becomes a lot easier.  There are already "gate openers" on the market that people use to open gates at the ends of their driveways, let out livestock, etc... one of those might be just what you need!

GlennA
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Gold
How are you with hand tools ?
GlennA   6/6/2012 9:51:57 AM
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Nadine J;  How are you with a tape measure, jig saw, drill etc ?  I opened the lower storm window, removed the window screen and fitted a piece of polycarbonate (Lexan also works) into the window frame.  I can remove the polycarbonate at any time to revert to a regular window.  I installed a cat door into the polycarbonate.  Then I added some insulation.  The inner double hung window still clears the assembly.  In the morning I open the window to let the cats out, and close it at night after they are in.  During the day they come and go as they please.  I didn't like the idea of a magnet-key in case the cats' lost their collar.  The outside window ledge is about 6 feet off of the ground - the cats use the central A/C unit as a step, but an uninvited human would find other windows more inviting if motivated to break in.  I also installed a cat door into a piece of 1/2 inch plywood that sits in the sliding door frame for use when we are home.

NadineJ
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Platinum
Re: How are you with hand tools ?
NadineJ   6/6/2012 2:08:52 PM
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@GlennA - I like it.  That's a great point about cats loosing collars.  I suppose you could embed a chip in the cat but that would increase the overall cost.  Shocking burglars is a tempting benefit.

I love discovering soloutions for renters in urban areas to live well without risking eviction. 

You've all inspired me to start that ebook...add to list.

novahokie
User Rank
Iron
Re: Very cool video
novahokie   6/5/2012 3:55:12 PM
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Thank you for your comment.  I definitely enjoyed making and watching back the video!  In regard to your idea about an opener that is triggered by a tag on a cat's collar, keeps out other animals not wearing the special tag(s), and locks again after they pass through, there are actually quite a few different ones available on the market.  Just google "automatic pet door openers" or "electronic pet door openers" and quite a few will come up.  This link will take you to one of the fancier ones that has a timer function and can handle multiple cats separately: http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=24097&cmpid=02cseaz&ref=4144&subref=AA  They're usually expensive, but these products have been available (especially for dogs) for a while.  The key point of my invention is that the freedom to come and go is instantly, remotely, and spontaneously when necessary, controlled by the owner, not the pet, for cases where the owner wants that type of control.  For example, you might want to keep your dog or cat inside until you're ready for them to go out, or outside until you're ready for them to come in, etc.

novahokie
User Rank
Iron
Re: Very cool video
novahokie   6/5/2012 3:58:16 PM
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PS:  I guess I should have identified myself in my post just now... I am the inventor, Les Kelly :-)

Rob Spiegel
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Blogger
Re: Very cool video
Rob Spiegel   6/5/2012 3:58:08 PM
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I agree, Nadine, this is a good gadget. With the remote (or the timer) it means you can let your pet in (or out) without having to get up early.

Charles Murray
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Blogger
Inexpensive
Charles Murray   6/5/2012 6:56:46 PM
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Nice job, Les. I always like to look at the BOM to see how expensive the parts are, and it looks like their's nothing expensive there (some of the parts weren't clickable, but none appear very costly). Cost is usually the governing factor on these ideas, and this seems doable on the production level.

novahokie
User Rank
Iron
Re: Inexpensive
novahokie   6/5/2012 10:04:48 PM
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Yes, at high volume the parts add up to about $10 per opener, including the remote control.

Rob Spiegel
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Blogger
Re: Inexpensive
Rob Spiegel   6/6/2012 12:40:15 PM
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That cost makes the gadget surprisingly inexpensive, Les. Were you seeking a design that would favor low-cost parts, or did it just work out that way as you put the gadget together?

novahokie
User Rank
Iron
Re: Inexpensive
novahokie   6/6/2012 2:35:16 PM
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When I made my 1st prototype I didn't care about looks too much, I was using 120V AC for power, and it probably added up to close to $100 to make it.  But once I started considering making them to sell and learned that the final retail prices you see in stores for things is usually 5X-10X what the materials cost it became obvious really quickly that I needed to optimize everything possible.  My investor, distributor, company heads, and others I ended up working with also convinced me that it needed to run on batteries, AND get smaller, all at the same time to be a viable product.  Those 3 conflicting goals let to what remains the biggest design challenge: getting enough pulling force AND enough stroke, using a minimum number of the smallest batteries possible (to reduce size).  As 1 of the readers mentioned earlier, the force solenoids can exert drops dramatically with their shaft extension, and I need my maximum pulling force when the shaft is fully extended, so I basically had to sacrifice some stroke length from what I really wanted to make sure it would have enough pulling force at that extended position to pull back the latch reliably when activated.  The flap version of this Gadget Freak has a little longer stroke than the original version for crates because the force needed to pull the smooth rod back out of the screw eye you see in the video is much less than what might be necessary to pull a latch back on a typical wire crate, due to friction I've seen a lot due to warpage of the crate panels, misalignment of the doors, etc.  But after all the dust settled though I reduced the $100 down to about $10, batteries included!

Rob Spiegel
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Blogger
Re: Inexpensive
Rob Spiegel   6/6/2012 2:46:32 PM
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Thanks for the detail, Les. I would guess this is a common way for a product in development. First you prove it without undue concern about costs. Once you have your working prototype, it's time to review the BOM and manufacturing process to come up with an economically realistic version.

William K.
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Platinum
Automating a dog door, or cat door
William K.   6/6/2012 10:04:35 AM
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Really, vertical opening is the only practical way to do it, since the door can close by gravity, which is much safer, and yet be constrained very well by the guide channels. A swing-action door would need a latch, which would add a lot of complexity, and still need a separate mechanism for opening and closing. A solenoid would not be suitable for either opening or closing because the force increases as the stroke progresses. The radio coller is the most common, although an RFID type system would work very well, but cost more. A proximity system would probably let all kinds of animals in and allow a major disaster. Picture a racoon attempting to escape after raiding the kitchen pantry.

Keeping humans from using a cat entrance could easily be done by electrifying the whole window frame. Cats are two small to touch both the window frame and ground at the same time, while a human would stand on the ground and make contact with the frame quite natrually. Yes, it would harm the burglar, but one could always claim that it was an electrical fault caused by thier tampering with the door drive mechanism. 

robatnorcross
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Gold
Re: Automating a dog door, or cat door
robatnorcross   6/6/2012 6:21:21 PM
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My families dog (Charlie) invented this decades ago. He trained the humans in the house to come and open the door at his command. He stood by the door and barked once. If we didn't respond in a timely manner he barked twice (you get the idea. When he wanted back in he did exactly the same thing.

May be people should just get smarter pets.

If WE were as smart as he was we would have taken out a patent.

hydrogent
User Rank
Iron
Re: Automating a dog door, or cat door
hydrogent   6/7/2012 12:33:59 PM
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William, Please tell us you are kidding about electrifying a pet door! It sounds like fun, but what about the innocent child that happens by & tries to follow the kitty? The charge would be murder.

Regarding the magnet collar sensor or other automatic lock-out that others mentioned, if we did not have such we would have neighbor cats & raccoons in our house

William K.
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Platinum
Automated pet doors
William K.   6/6/2012 10:19:16 PM
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The successful doors that I have seen did not use a solenoid to open the door. Not only is the force to displacement curve the opposite of what is required, but also any solenoid able to do the job will draw way too much current. The commercial units that I saw used a small motor to raise the door, which does a far better job and consumes less power.

William K.
User Rank
Platinum
dog and cat door.
William K.   6/7/2012 9:19:26 PM
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I don't think that any "innocent child" would be attempting to enter a window that far above the ground, or, for that matter, why anyone innocent would be attempting to climb in a window. Anybody living in that house would already know about the connection and avoid the problem. OF course, an alternative to a direct line connection would be an electric fence charger, one of those used to keep cows in place. OF course, you make the assertion that any ac line shock is always fatal, which is incorrect. They may be potentially fatal, but the vast majority of 120 volt AC line shocks are not fatal. We only hear about the very few ones that are, we get no reports about shocks that are merely painful. 

The original description was of a cat door placed quite a distance above the ground at a height that a child could not possibly reach. Most innocent children don't jump up that high. In fact, most innocent children are not six geet tall, as I recall.

As for live wires, I had to take some extreme steps a while back when the bulbs from my post light were being stolen repeatedly. I doubt very much that it was an innocent child taking out the glass and stealing the bulbs. 

Cadman-LT
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Platinum
Off question
Cadman-LT   6/11/2012 6:00:16 PM
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This just made me think of something that one of you maybe can answer. Do they make sensors for rooms so when you walk in the lights turn on and off when you leave? Light switches just seem so outdated...lol

Tool_maker
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Platinum
Re: Off question
Tool_maker   6/15/2012 10:10:48 AM
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I am sure you are kidding as many public restrooms already use such a system. As for the pet door, we have trained our Border Collie to ring a bell tethered to the doorknob when she needs/wants to go out. I am sure many dogs could be trained to activate the pet door in a like manner. I guess a timer could be utilized to lock it after a reasonable amount of time and a separate opener on the outside.

Cadman-LT
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Platinum
Re: Off question
Cadman-LT   6/20/2012 8:45:30 AM
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Yeah, it was just a joke. Seeing if anyone was paying attention. :)

Cadman-LT
User Rank
Platinum
Re: Off question
Cadman-LT   6/20/2012 8:48:56 AM
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I still want to do it...just looking for the cheapest way. So it was a joke wrapped up in a true question...kinda. Any advice on the cheapest way is cool with me.

Tool_maker
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Platinum
Re: Off question
Tool_maker   6/20/2012 12:53:52 PM
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I am sure it is something you can buy off the shelf at Home Depot or Lowe's.

Cadman-LT
User Rank
Platinum
Occupancy Sensors
Cadman-LT   7/3/2012 11:11:15 AM
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Yeah, they are called occupancy sensors. They are put in places such as restorooms. I thought someone would have called me out on that. 

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