Cat flappery

[ian]

As the kittens are now old enough to hold their own against even the most fearsome of the local wildlife (even the squirrels wear hoodies around here) they now have their own cat flap into the back garden via the french door. They seem pretty happy with their new found freedom to come and go as they please.

But there's one fly in the ointment. Well, actually it's young ginger tomcat. Now, he's a nice cat, very friendly. He likes the cat flap too, not to mention the free lunch, and comfy warm places to snooze. This doesn't really bother me. Alas, our cats just don't like him. I did hope they'd eventually settle their disagreement but they simply don't want him in their little gang. They used to be able to bully him, but he's getting bigger by the day, and I think the days of bullying are over.

At present we have a basic, manual cat flap that is lockable (allegedly, La-La can open it even when locked). I did look at replacing it with a magnetic or infra-red version but experiments in collar wearing haven't gone well and after a day I found the mangled remains of both collars under the sofa.

I did notice that there are now cat flaps opened by the transponder chips. Has anyone got one - they're not cheap, but both cats are chipped and it seems an ideal solution? I'm a bit worried about the range - the transponders are, I assume, very low power and require induction, and I know the vet's scanner wand has to be pretty close to the chip to read it. Anyway, I figured I'd ask if anyone knew anyone who had any experience of such a device.

[border-rider]

I'm also interested

We have a strange cat who's taken to coming in.  Strange as in odd

He just wanders in and starts eating, and if I shoo him or chuck water at him he just looks all hurt and carries on eating.  I picked him up and chucked him out of the (downstairs) window yesterday, and back he came.  Our Big Cat growls and menaces him but he just doesn't play.  He just ignores him, which really irritates Big Cat.  But because he doesn't follow the rules, no fight can ensue.

We don't want to fit collars, so we were wondering about the chip-operated catflaps.  As you say, I bet they're very short-range though

[Analog Kid]

We also considered this as an option about 6 or 7 months ago.  I think there was a thread on this forum that mentioned the technology about that time (although I can't find it) and since we were being invaded by a tom cat on a daily basis it seemed a good idea.

Apparently there is more than one type of aninmal ID microchip used and it seems they have evolved over the years. The cat flap manufacturers website had a "compatibility check" area where you could enter the type chip your cat has and you are then advised wether or not it'll work. The chip info should have been supplied by the vet at the time of 'installation". Turns out that our two cats, chipped about 9 years ago, weren't going to work so they now have collars.

As suggested earlier I don't think the working range is fantastic but, like the other types of lockable cat flap, as long as your cat isn't being chased into the house a slight delay in opening isn't that significant.

[TimO]

... I think there was a thread on this forum that mentioned the technology about that time (although I can't find it) ...

That may have been the one I started, although it didn't really answer the question "do they work?"

I'm still in the process of thinking about getting a cat, but was going to drill a hole in the wall for the tumble drier, so was thinking of fitting a cat flap at the same time (there's a convenient location in the utility area, where a cat could easily go in and out, and this doesn't require me to get a hole maid in the double glazing).  Any cat I'm going to get is likely to be a rescue cat, so will likely come pre-chipped.  If not, I'd get it chipped anyway, so the chip ought to be relatively modern, and work with these devices.

[ian]

Well, I fired off emails to the two suppliers with some questions, so I await their responses. I did read online that with the newish FDX-B chips there should be no problem detecting even at several centimetres distance. I am a bit surprised by this, but I'm no expert (this should perhaps give us a little to think about before sticking RFid tags in passports).

As the ginger tom was asleep on MY bed earlier, I think I'll give one of them a try. Provided they fit the current hole, of course, which they might not and I'm not buying another custom double-glazed unit. Our little critters will need to learn to defend their territory. I may change this stance if I come home to a house full of foxes.

[TimO]

On the Pet Porte website, they do have things like the glass cutout dimensions, which is more or less rectangular.  Since most cat flaps seem to have round holes, this could be a problem.

I'm planning on hacking a hole in the wall, so aside from buying the version with a longer wire (for use in walls tunnels), I shouldn't have any hole shape issues.

Incidentally, if you're buying a Pet Porte online, Pet Porte seem to be cheaper than Microchip Cat Flaps (I think Pet Porte, who are in Guernsey, are the original manufacturer).

Pet Porte : £105 + £6.95 p&p = £111.95
Microchip Cat Flaps : £127 with "free" UK delivery.

[ian]

Sadly the Pet Porte won't fit the current circular hole (though they tell me they're doing an adaptor in the new year) - I quite liked that one because it had a day/night function. Not heard from Sure Flap folks.

I'd only buy the Pet Porte from the Guernsey suppliers. Not only is it cheaper, the guy behind Microchip Cat Flaps is a bit of a well-known twunty spam monster.

[TimO]

Well, I've got a Pet Porte on order now, since it looks like I'm re-acquiring my old cat back.  My ex has been having problems with him, and it looks like I'll be taking him on, so I need a cat flap of some sort for him (once he's been in the house for a couple of weeks minimum, and "reset" his location memory).

[TimO]

I just picked this up from the local sorting office (they tried to deliver yesterday when I wasn't in), which isn't a bad delivery time for the Channel Islands (Play occasionally takes longer, and mostly that's for a thin Jiffy bag).

After some quick experimentation with my compliant test subject (ie Talisker The Black, Destroyer Of All Small Things Who Go <Squeak> <Crunch>), it seems to work OK "in the lab" as it were.  His chip must be almost ten years old, but was programmed in, and worked, first time.  It beeps when it detects him (the normal mode, it can be made quiet), which doesn't seem to significantly worry him.  The electromagnet for one of the latches wasn't quite seated correctly, which initially stopped it working, but once I pushed it into position, it now works fine.

I'll have to install it in the next few days, the clouds of dust, power tools, and mortar definitely will annoy someone.

Further results to follow when installed.

[TimO]

I haven't had time to install it yet, just wave it near Talisker and see if it locks/unlocks (which it does).

I've taken a few photos, pre-install.  They aren't very good, since I've mislayed the battery for the SLR, so they are taken with the el-cheapo 3M camera, and it's crummy flash.

The section which goes inside, the black dot at the bottom is the socket for the power jack.  The bits at the top are a green paw button and green cat LED, and red paw button and red moon LED.  The various modes are selected by different combinations and durations of holding down the buttons.  The LEDs then show what's happening by either being continuously on or flashing.

The section which goes outside, the porch contains a large coil which communicates with the RFID chip.  There is also a light sensor for the Night Mode.  The cable plugs into the other section when you've installed it.

All the remaining bits, a fairly extensive manual, a wall wart power supply, and a small bags of fixings.

[TimO]

That's pretty much what the cat flap looks like at the moment!  (Actually it has a paving slab over it to stop the other local cats from wandering in).

Since that photo was taken it's been slightly enlarged, and squared up a little more.  The tunnel has been built and checked for size.  I had to put some end pieces on it, partly to hide the crummy hole, and partly because of the construction of the flap itself, which is really designed to go into a door, so doesn't work quite correctly with brick walls.

The wooden bits have been given a single coat of weatherproofingness, I'll do one or two more, depending on time.  The tunnel will go in, and probably be partially mortared in to fill the gap around it.  I'll fit the end pieces, and seal the wire along the inside edge of the tunnel with some sealant.  Finally I'll put sealant around the edge of the cat flap wood interface, and the wood to wall interface, just to seal things as much as possible.

Given the current forecast, I won't be able to finish this until Tuesday, tomorrow is wet wet wet.  Talisker will not be best pleased, since he's had free rein outside for the weekend (daytime), and he'll be locked in again tomorrow.

It looks like I'll need to build him a little set of steps, although a couple of paving slabs will probably do for the immediate future, and to check things for size.

ps I was wrong about him being annoyed by the building work.  He's walked through the hole, and reappeared covered in dust, which he utterly fails to remove, scruffy bugger.  He'll also wander nonchalantly past me when I'm drilling through the wall with a hammer drill and humungous mortar bit, my ears almost bleeding from the noise.

[TimO]

OK, after much more buggering about, it's done, so Talisker can get to the serious work of ignoring it!  Even though he's used a cat flap for pretty much all of his life, and should be used to them, he doesn't seem to be keen to use this one.  It may be because it's in a wall, and he's used to them being in doors.  This may be confusing him.

Still, once he's hopping from paw to paw and desperately needs to go, I'm sure he'll work it out!

The interior still needs to be tidied up, and the power cable needs to be properly fixed to the wall (and probably made chew/claw proof!)

[Notsototalnewbie]

Nice job TimO, Talisker is lucky to have you.

I'd consider a dog flap for the dog if she was more interested in the garden, but she isn't. Won't even use it as a loo. Plus it would involve a double-glazed door which I expect complicates things.

[TimO]

I small dog could use this flap, it's huge!

When I left for work, I couldn't find him, he's obviously wandered off to find some of the locals to have a fight with (or more likely run away from!).  I loaded up just inside the flap with treats, which may tempt him if he can see them, but will certainly tell me if he's managed to get in, since there is no way he would leave them uneaten!

There are people out there who will cut holes in double glazing units for cat flaps and the like, although it probably nullifies any guarantee, and will probably allow moisture into the unit.  I suspect you can have new panels made, with the holes already cut in them, if you're willing to pay enough!  Partly I wanted to avoid cutting a hole in the relatively new double glazed back door, and there was room to knock a hole in the wall in the "utility room" (actually a small lean to / extension bit on the back of the house).  There was no real other use for the location, it's underneath the central heating boiler, so a cat flap is as good a use as any.

[Analog Kid]

Thanks for the update TimO.

I realised when reading your post that I'd never thought about power requirements. Does it run off batteries or is it only mains powered and if so how does it cope with a mains failure?

[TimO]

This one (Pet Porte) is mains only, the other one (Sure Flap) is battery only.  I think the RF ID reader can be quite power hungry, so mains power seems a good idea.

It uses a small DC power supply (wall wart), which is probably a good idea since (i) most flaps will be installed into doors, so you need a flexible link across the hinge, a cheap replaceable piece of low power DC wiring is easy and safe, doing this with mains would be a lot harder (and probably more expensive) (ii) there is clearly a risk of water ingress if the weather is particularly inclement and the fitting is less than perfect.  Mains power and water do not mix well, whereas a small DC power supply at worst will probably just fail, and not pose a safety hazard to anyone (iii) The cable has to be close to the cat flap, so is just asking to be clawed or chewed on, again this could be a bit unsafe for a cat, and armoured cabling would also complicate things!

The solenoids which control the flap seem to be two position devices, so when unpowered will just stay in the position that they are in.  If the device is left in it's default state, this means that the cat will be able to get out, but not back in again.  I think that the device will retain some settings, eg the RFID chips that it recognises, the light level that Night Mode engages at, and the time delay that the flap stays unlocked for after the RFID chip has been detected, but it seems that any modes like Night Mode, Vet Mode, or Open Mode which you've left it in are forgotten, and it defaults back to the normal open to all going out, and locked except to recognised pets coming in.

Power cuts are pretty rare in this country, I think I've been aware of two or three in the eight years that I've lived in London, and the longest was less than a couple of hours.  If you did have more frequent cuts I think there are two options (i) You could home-brew a DC supply, with a Nicad or Lead-acid battery on trickle charge from the power supply, and which could run the cat flap for a few hours, or probably days when the DC supply failed.  For this it probably wouldn't need to be a lot more complex than a couple of diodes and a resistor to limit the charging current.  (ii) You could just buy a small off the shelf mains UPS, as used for PC backup.  It would be less efficient, because of the Mains-DC conversion, but since they are sized to power small PCs and larger, which draw a lot more current than this cat-flap, they would probably run it for days.

[JT]

When we were on holiday in July, we locked the cat flap with the 3 cats inside. The flap was covered in a cardboard box that was gaffa taped to the door. My mum was feeding them a couple of times a day and seeing to their littery trays, etc. She doesn't like dealing with the many small animals and birds that they were likely to bring home. Plus we knew they'd be safe.

Anyway, Alfie somehow managed to batter his way through the box and then broke the cat flap completely in his need to get out. I replaced it but now he's worked out a way of getting the door off even when it's locked (without breaking the whole thing thankfully).

With a flap as expensive as the Pet Porte I'd be worried that it might not be Alfie-proof.

Incidentally, our cat flap is in our French patio door and we were able to get a new double-glazed sealed unit for £150. We have the original in the garage for if we ever sell the house to someone who doesn't like cats.

[TimO]

Just as a quick follow-up to my previous post; Maplins will sell you a 650VA UPS for £40.  The manual for the Pet Porte says that the power supply is 10.4W, so naively this will power the device for 60+ hours.  Having said that, the efficiency is quite possibly not that good when running over a long time, there will be losses which are not scaling linearly since it's designed to power a much higher load for around 20 minutes.  I'd guess that it would probably work for over 24 hours.

[TimO]

Anyway, Alfie somehow managed to batter his way through the box and then broke the cat flap completely in his need to get out. I replaced it but now he's worked out a way of getting the door off even when it's locked (without breaking the whole thing thankfully).

With a flap as expensive as the Pet Porte I'd be worried that it might not be Alfie-proof.

Hmm, I'd say that I could break the mechanism by pushing it fairly hard, or hitting it.  I don't think Talisker could, but he's not a terribly big or aggressive cat.  This image gives you some idea of how small the tabs are which hold the flap closed.  They are only small bits of plastic a few mm across, which are slid sideways by the solenoid.

It would require a fair bit of force to break them, and I imagine if that happened, that Pet Porte could supply replacements easily enough.  They may even be interested in the broken ones if they wanted to develop a larger flap.  Conceivably a large flap designed for dogs may need to be somewhat more ruggedly built.

I think you could modify it to be a bit more solid, but that would likely need larger solenoids, so may well be beyond someone who isn't willing to bugger about with the electronics a fair bit.

[TimO]

It turns out that he is too stupid to work out what the cat flap is, even though he's used one for pretty much all of his life.  He managed to sit outside in the (slightly) cold and dark waiting for me, even though he could have walked in at any time.

I see much shoving in and out of the flap, with various bribes to encourage him through, in my future.

[border-rider]

We changed our RFID catflap for a newer model (after a local cat knocked it clean out of the door) and our old cat didn't ever get on with the new one. 

She used to open the flap with her paw outstretched and then go through.  Because the sensing range of the new one was smaller, she was pushing the door before the catch had dropped (she had long legs).

[TimO]

My sisters old cat didn't like it when she swapped the cat flap for a magnetic one, to keep the other neighbourhood mogs out.  She did the same, and somewhat daintily used to open the flap with her paw.  She did get used to the new one which she had to head butt, so that the magnet on her collar could unlock the mechanism.

This one should work OK, it certainly has time to sense Tali and unlock, and he always used to just smack into the flap with his head, so it ought to still work like that.  I think he just isn't used to a flap which isn't in a door, it's degree level thinking for him, and he hasn't quite grasped the entire concept.

[ian]

...
Anyway, Alfie somehow managed to batter his way through the box and then broke the cat flap completely in his need to get out. I replaced it but now he's worked out a way of getting the door off even when it's locked (without breaking the whole thing thankfully).
...

One of our cats is quite adept at breaking in (and out) via the current cat flap, she gets her paw through and manages to force the flap over the catch. Fortunately the tomcat interloper we want to keep out isn't so smart (or persistent).

I'm sold on the Pet Porte, but alas the current version doesn't fit the hole in the double-glazed sealed unit in our french door (and I'm not paying to have yet another one made). There will be a version for circular holes in the new year. Yeah, the ginger tom appeared about two days after we'd had the pane made and current flap fitted. Grumble.

I never got a response from the Sure Flap people to my queries. Might get around to calling them since that would probably fit and having to throw out someone else's cat at 3am isn't my idea of bedtime fun.

[TimO]

After a week, and with much propping open over the door, bribery with snacks, and occasionally just shoving him through, Talisker seems to have accepted the cat flap, and has been using it all evening.

I think I need to pop the inside mechanism out, and cut some bits off the wood which is limiting how well the door opens, but aside from that it seems to work pretty well.

After some consideration, I realised that I should have taken the antenna coil out of he porch, and integrated it into the top of the tunnel, it would have been protected better from the elements, and wouldn't be at any risk of damage.  Ah well, next time!

Interestingly, if he sits under the porch the latch stays open, and the five second delay on it locking doesn't start until he leaves the range of the sensor (as he walks through the tunnel).  I remember seeing a comment from someone who use the other RFID flap, which is battery powered, that their cat sat next to it, and it repeatedly cycled, and flattened the battery.  There's no risk of that with the mains power of this one.