Remote Control Cat Harness




Posted in TechnologyElectronics

Introduction: Remote Control Cat Harness

About: My name is DJ and I previously made electronic whatsits, 3D-printed thingamabobs, and laser-cut kajiggers for the Instructables Design Studio; now I build and repair puzzles for Escape Industries.

Yes, you read the title correctly. Don't worry, no cats were harmed in the making of this project. Cats are fun in their own right, but this is 2014! Isn't it about time we brought cats into the modern era? And by bring into the modern era, I mean combine with lasers. In this Instructable I'll show you how to turn an off-the-shelf RC toy and a laser pointer into a wacky way to accessorize your feline friend for hours of fun.

Step 1: Parts and Supplies

RC helicopter (RadioShack #: 60-958)

laser pointer (RadioShack #: 63-1064)

micro servo (RadioShack #: 273-765)

NPN Transistor (RadioShack #: 276-2016)

1 K ohm Resistor (RadioShack #: 271-1321)

AAA battery holder (RadioShack #: 270-398)

(2x) AAA battery (RadioShack #: 23-2214)

(6x) AA battery (RadioShack #: 23-2212)

cat harness


live cat

Step 2: Modifying the RC Toy

First we'll need to take apart the helicopter to get the electronics . We wont be using the built in motors, but we will be using the IR receiver and main circuit to control our servo and the laser light.

Once we disassemble the helicopter, it won't be readily repairable, so take a few moments to fly it around and crash it to your heart's content. We don't need the propellers anyhow.

The toy helicopter is held together with a ton of tiny little screws. We'll need to remove all of them to get to the heart of the toy inside. Using a small phillips head screw driver, go to town on the toy and remove any visible screws and pull apart the now loosened plastic bits. Feel free to hack away at the little helicopter since we don't need any of the components except for the main PCB. Out of curiosity I decided to try to disassemble it as much as possible without resorting to cutting or breaking anything. Amazingly, most of the toy is held together without any glue or tiny heat welds, which is quite impressive! Safely remove the PCB once it is free from the body and snip the wires to the motors, light, and battery. Feel free to use them to make the world's smallest personal fan, or perhaps upgrade a paper airplane to a powered version.

Step 3: Modifying the Micro Servo

First, peel off the stickers along the servo case.

Using a small screwdriver, remove the tiny screws at the base.

Pull out the driver board. Clip the two wires leading to the motor off and set the driver board aside.

Cut a length of the original servo wires and strip the ends.

Solder the new wires to the motor so it will extend outside of the case.

Replace the base of the servo and tighten the screws.

Having printed the micro servo mount, threat the wires through the hole near the base.(The .STL file is attached)

Press the micro servo firmly down into the mount.

We'll be driving the servo motor with the rc toy's electronics, so we wont be needing the servo control board.

Step 4: Modify Laser Pointer

The full laser pointer is far to bulky to mount to our wee servo, so we'll need to remove the diode and driver from the body tube.The diode module is held firmly in place by friction at the tip, so we'll need to pull it out. I ended up using a vise and pliers to pull the pointer apart.

Once the diode is free, clip off the the spring attached at the end. The spring metal is quite hard, so use some heftier snips to clip it off. I nearly ruined my regular flush cutters, so be warned!

Solder two lengths of wire to the module. Looking at the top of the board, the anode is located at the middle contact of the diode and the cathode should attach where the spring is soldered to the board.

Solder to both ends of the the button with a tiny length of wire. This way the module is permanently "on" when powered by the RC electronics.

Step 5: Solder Electronics

Time for the real modifications! The original battery that powered the heli was rechargeable, but quite small. In addition, the laser driver runs off of ~3 volts. The original LiPo would give 4.2 volts down to 2.7 volts, which could potentially damage the driver. The servomotor originally required 4.5 to 6 volts, but the bare motor will run at much lower voltages, so it will be ok. With all of this in mind, we can safely assume a nice 3 volt average will run everything quite nicely. With two AAA batteries, we'll get the power we need and an increased run time to boot. Just be sure to use regular non-rechargeable batteries (rechargeable batteries wont give us enough voltage, and we still wouldn't be able to use the built in charging circuit)!

Solder the connections for the battery pack to the B+ and B- pads on the main PCB.

Solder the anode (red) wire from the laser to the B+ pin.

Solder the cathode (black) wire from the laser to the collector of the transistor (the leftmost pin when looking at the flat side).

Solder the 1K resistor from the L+ pad to the base of the transistor (the middle pin).

Solder the emitter pin of the transistor (the rightmost pin when looking at the flat side) to the L- pad.

Solder the motor wires to the M+ and M- pads respectively. The polarity doesn't matter for this connection, since we can just flip the servo horn to match the movement we want.

Step 6: Mounting the Electronics

I created three separate mounts for the electronics to make everything easily and firmly sewn to the harness. I designed the parts in Autodesk Fusion 360 and printed them out of PLA on an Afinia 3D Printer. Download the attached .stl files and print them out. The battery pack should snap into place, but the RC PCB will require a dab of glue to remain secure in it's mount.

Step 7: Prepare Cat

Depending on your patience level, this step can either take two minutes or two weeks. The instructions that came with the harness strongly suggest familiarizing your cat with wearing the harness for a couple weeks. This includes keeping the harness where your cat tends to sleep, in addition to taking the cat out for walks with it on. I opted to skip this step, but it should aid in your cat's attitude towards wearing it!

Attach the assembled unit to your cat. (Your cat may enter into a trance-like state of awe upon being upgraded. This is normal)

Step 8: Have Fun!

Now that you've got a fully upgraded cat, enjoy piloting it around your living room!

Possible upgrades:

More lasers! Enough said.

Full Pan/Tilt motorization for more precise positioning.

Dog-mounted lasers? Heck, why not add lasers to all your pets! (Bonus points for aquatic friends)



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    it's a great build but..... if I put even a body harness (thin straps) all my cat will do is lie down & stay there, you can hook a leash to him & drag him about.

    Cuuuuuutiiiies <33333

    Get 'em, fluffy! Kill!

    (But why does my car stereo have a remote control when it's already within reach? Anybody?)

    Remote sensors on my cat and I'll know what's going on in the neighborhood. Nice instructable.


    Seriously! And if the cat decided to go walkabout wearing this upgrade , you would have dozens of reports coming in about a cat wearing a bomb . Who knows ... Maybe "Fluffy" won't even come home after the anti terrorist bomb squad have had a go ! Otherwise an interesting project . Maybe mount a camera and send agent 008 on a spying mission ?

    1 reply

    Haha, you've made my day! Best comment so far :)


    The specs on the laser pointer state "Danger - Laser Light. Avoid direct eye exposure." Considering that people can be stupider than chickens I think wise to re-state that caution here.

    Cats are very quick and agile, and one has to be very careful when operating this to avoid anyone being laser-eyed. If you operate this outside and the cat points it up at an aircraft I think it would be the operator and not the cat who would end up pounding rocks in federal prison.

    I'm sure kids would just love this controler, but I'd think they should be closely supervised when using it.

    6 replies

    growing up in the early 80s, we had a HeNe gas laser that had a nominal output of 5mW, younger me loved it, the cats loved it, and not a one of us ever had any eye damage from it.

    that power level, with that wavelength will leave after images AND if you look into it long enough, it WILL cause your retina to bleach temporarily (everything goes black and white in that eye until the rhodopsin has a chance to relax back to its normal state. it sounds major and feels incredibly weird, but it didn't have a permanent effect on my eye); from long experience with both cats and lasers of various power levels and wavelengths, I can safely say that the primary concern is being aware of where you are guiding your photonically enhanced kitteh.

    For about 5 bucks you can get a pet safe laser toy at Pet Smart. Still has the "avoid prolonged eye exposure" warning, but seriously, a cat won't do ANYTHING prolonged, let alone something uncomfortable like staring at a laser beam. This is a toy that promotes a little activity and would be beneficial for an otherwise sedentary feline companion.

    A standard laser pointer isn't all that powerful. 5mw isn't enough to damage your eye except by prolonged staring into it. It CAN make afterimages that take a long time to go away, so reasonable caution is indicated, but paranoid avoidance of a 5mw beam is goofy. If the cat sweeps you with the beam, don't panic and flail about as if you've just been sliced by a lightsaber, trust me, you'll live. What you should NOT do is arm your BorgKitty(tm) with a high-powered 1-2W laser module capable of lighting things on fire and blinding people in a split second. That would be an irresponsible arming of a cat, which already is secretly planning to murder you in your sleep, with a destructive device.

    This is covered under the Geneva Convention under "arming of felines with weapons of mass destruction". Don't do it, you'll be saving the world if you don't. Further information on this topic is available in this infographic:


    Well I'm relieved that these pointers are not so dangerous. I would make one for my cat, but this particular purrball is bored with laser dots. Go figure.

    OMG, "Like!" Thanks! :) I'll let our fellow catizens know their conspiracy is futile. They can only have RFID, not the laser cannon.

    As ardrhi says, a regular laser pointer is usually not harmful for the eyes unless you purposely stare into it for an extended duration..

    As to your second warning, you're lucky if a standard laser pointer dot makes it to 20 feet, let alone 20,000. So realistically, a laser pointer pointed at a plane in the sky really wouldn't do a thing. Well, other than make the person pointing it up there look a bit silly.

    looks like the jaeger bomber cat outfit on top pic.

    One question, why would you do this? Seems weird although the cat is unfazed. Mine is semi feral and can't even get a collar on him

    LOL! Very clever! I've heard they tried something similar with sharks using electric impulses instead.

    Is there no Home Automation contest for this to win!?!