The Cat Launcher - Energetic Cat's Workout Toy or Just a Lazy Owner




About: I am a University of Edinburgh electronics engineering student.

Here I'm glad to present to you my next invention!!! - The Cat Launcher

This toy is for your cat or dog or other lovely friend that is going absolutely CRAZY to chase a moving object! 

With this crazy machine you pull the string away from it ... place the string with the SHINY object at its end in front of the cat ... back off ... and ... press the launch button!

And then what you see is an animal desperate to catch the attractive bow!

Step 1: Lazy Cat in Action

Here is a short video that shows the Cat Launcher in action!

Step 2: How to Launch the Cat?

1: Put the switch to Astronaut mode.

2: Press the launch button and enjoy the cat orbiting around.

I'm sorry for the blurry photos, but cat is too fast!

Step 3: Parts Supply

These are the basic parts needed. 

LEDs may be skipped, I have them just to make it more interesting.

You need:
  • A plastic box
  • Switches
  • Small DC motor from a toy
  • Reel and string
  • Battery holder and batteries (holder for two or three 1.5V batteries)
  • Cables and heat shrink tubng
  • LEDs (optional)
  • Labels (optional)

Step 4: Tools Needed

You may need:
  • Drill and bits
  • Knife
  • Gauge
  • Soldering iron and soldering wire
  • Zip ties
  • Cable cutters and Pliers
  • Hot glue

Step 5: Layout Planning and Connections Circuit

The circuit schematic shows all the connections. For simplicity one of the speeds can be omitted as well as the LED.

Ensure that the box is large enough to fit the motor, battery holder as well as the switches.

Step 6: Battery Terminals

I used a battery holder out of a flashlight. 

Because the motor spins too fast at 4.5V, I soldered a cable at the 1.5V spot to have two different speeds for the operation.

NOTE: Use the first positive terminal as shown on the schematic diagram. The negative terminal is common for the two speeds.

Step 7: Motor Connectons and Reel

Solder two cables to the motors terminals and insulate with shrinking tube.

I used hot glue to attach the reel to the motor axis.

Step 8: Motor Stand

Using a piece of soft white plastic I made a stand for the motor. I cut two slots for zip ties and tied the motor to the stand.

Step 9: Buttons Control

Drill two holes in the box to fit the buttons. Here you may need the gauge to measure what is the button diameter to determine the drilling bit.

One button changes the speed of the motor, other is the Start/Stop control.

If the box is very soft start with a small bit and progressively increase the size.

Step 10: String Entrance Hole

Just drill a hole on the side of the box where the reel rotates. Align the reel and the hole

I used a soft rubber piece to lay over the hole and protect the string from the harder plastic.

Step 11: LED

LED is soldered and its wires are insulated using the shrinking tube.

Step 12: Limit the LED Current

Voltage drop on LED = Resistance * Current

Resistance  = Voltage drop on led / Current  = 2.5 V / 15 mA  = 160 Ohms

160 Ohms resistor is enough to limit the current through the LED to 15 mA.

NOTE: The LED will have sufficient current through it to light it up only when powered at the higher voltage with the resistance in series with it.

Step 13: Mount the LED

A hole is used to keep the LED in place just where the string enters the box.

Step 14: Soldering Time

Ideal soldering iron temperature is about 380-390 degrees Celsius.

All cables are soldered and insulated with heat shrink tubing.

Finally zip ties tidy the mess and the connections look better.

It's a good idea to keep any wires away from the string and reel.

Step 15: Apply Hot Glue

I used hot glue for the motor base and the cable that supplies power to the LED.

Step 16: Foam to Restrain the Wobbly Bits Around

I used some kind of porous foam to help me keep the battery holder from wobbling around. 

Could be hot-glued to the box too.

Step 17: Printing Labels

I had a printer at my disposal and printed some nice labels to show what each button is for. 

One label is to change the speed from casual walk to astronaut's space travel speed.

Other for the string pull.

Step 18: Roll the String and Voila!!!

Finally the reel needs a string that has something attractive to the cat's preference.

I used about 5m of string (15 feet).

I also hang a wrist wrap at the side of the box.

Step 19: Work Hard Play Hard

All has been said, if you like my invention, please vote for me in the contests I've entered!

Comments are very welcome!

For everyone who reproduces this instructable I will give a free 3-month Pro Membership as a reward, just post a photo of your Cat Launcher in the comments below!

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Finalist in the
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Second Prize in the
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Finalist in the
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    43 Discussions


    3 years ago



    4 years ago

    what if i use 2 battery pack that each contain 2 battery


    4 years ago

    Super nice work on the electronics, my projects never look that tidy!!

    hah! i thought of this idea myself and came on here to see if anyone did the same thing. creepy how similar our projects are actually. where did you find a spindle/reel like that though? mine's too shallow.


    5 years ago

    How the HECK did you figure out how to make that?!! Lol. Awesome job and idea tho! :)


    5 years ago on Introduction

    what an adorable kitty. I been using a lazer pointer but the batteries can get be hard to find. Think I will try this out.


    5 years ago on Introduction

    HI!! I am very sorry that this response took so long.... however I had a lot to think about and other things got in the way of this project. I have thought about what you said and the motor is a high speed motor from radio shack. they don't sell much low powered motors but i found one and it is a 1.5-3 volt dc motor that I think will suit my needs in the toy. It will run at 11,600 rpm with no load on it. It's dimensions are fairly small as around 2.25 inches in length and not even an an inch in height. I will try to find a enclosure for it, and have found some suitable enclosures. as for the batteries I am partial to the three triple A battery pack because I already have a bunch of nine volt battery clips. Finally I will need resistors to have the variable speed but which do I need? please be very specific for ones that I need for the triple A battery pack.


    5 years ago on Introduction

    I wonder if my 7 y.o. male cat or 8 y.o. female cat will love this. It looks awesome!!! You got my vote.

    1 reply

    5 years ago on Introduction

    I am currently building the cat launcher for my very lazy cat, however i have some difficulties. first I can't find the perfect box. Second I am using a 9-18 volt high speed motor, and I think this is too fast for my cat to follow. any suggestions would be helpful although I don't want to buy another motor can u just tell me what do I need to slow it down. it will be powered on a 9 volt battery

    1 reply

    Reply 5 years ago on Introduction

    Hi! If you use this motor I am afraid it will drain the battery very fast. How big is it? I mean in physical size? Also, what is it from?

    I would suggest to use 4x1.5V batteries to reduce the speed. Or even less, three batteries could also work. On the other side the less batteries you have, the worse because they will be drained too quick. Probably find a smaller motor.


    5 years ago on Introduction

    Cool toy - what we do for out pets! Only one suggestion - the wiring for speed control will result in one battery being drained a lot more than the two that boost for higher speed. Look into using a 555 timer and PWM to control speed, that way you can have a knob with full range of speeds and you don't drain one battery more than the others.

    1 reply

    5 years ago on Introduction

    Cool idea / gizmo.
    Gotta give em lots of exercize.

    This gave me an idea to have the string / bait
    go between 2 pulleys so that
    you dont have to real it out every time.
    One of the pulleys is motor driven,
    perhaps randomly to add some variety to it.
    The action would then be unattended.
    You can just sit back and watch / record the fun.

    My cat loved chasing a laser spot.
    He d do it for 5 min til he came up wheezing!

    2 replies

    Reply 5 years ago on Introduction

    Nice idea with the two pulleys. Is it just an idea, or you intend to do this?

    And yes, cats love laser spots, I agree! :D