Intro: Very Silent Homemade Hamster Wheel Using an Old Hard Disk Drive
Pachita the hamster was driving me nuts. The squeaking sound caused by the friction of her wheel (combined with the cage vibrating) sounded like a freight train in the middle of the night. I asked for quiet hamster wheels on pet stores but they cost a lot, so I decided to make a home-made version.
This construction is different from other wheels found on the net because it will use an unexpected material: An old hard disk drive. You can scrap it from any old desktop computer.
Step 1: Required Materials
- An old hard disk drive scrapped from a desktop computer.
- Torx screwdriver to open up the hard disk.
- Big cookie can or similar.
- Metal scissors or a method to safely cut the can.
- Hot glue
- Small zip ties
Find the biggest can as possible, if the size is too small the hamster will not run on it, or will run on an unhealthy posture.)
If you love electronics, you can also get a soldering iron to solder some cables to the hard disk motor. We will talk about that later.
Step 2: Removing the Platters
Remove the screws and take the cover off. Watch out for a screw that is hidden under the adhesive label.
Step 3: Getting Ready to Extract the Spindle
Notice that the Spindle (that’s the technical name of the motor that holds the platters together and make them spin) is now fully accessible. I know it’s a motor and not the “bearing” per se, but believe me, it makes wonders.
Step 4: It's Out!
In the case of my hard disk, the spindle assembly is held on the frame by three screws. Removing them will set the spindle free. The ribbon cable that connects it to the printed circuit board will detach without too much effort.
Step 5: The Can
I have chosen this beer can due its big size and lightweight. A cookie can or similar will work too.
Step 6: Tracing the Cut
It’s almost certain that you will need to trim the excess of material. To trace a perfect circumference I used a sharpie fixed on a steady surface. One or two revolutions of the can resulted in a perfect circumference.
Step 7: Cutting
Use a set of scissors specifically made for metal to cut the tin can. If you don't have one please borrow them, they will save you a lot of time (and are much safer than using a knife).
Please be careful and use protective gloves: Cutting the can produces very sharp edges that will cut your skin at the slightest touch.
Step 8: Can Ready!
This is how the product looks. Wash the can but avoid painting it! the solvents may harm the hamster. We will get rid of the sharp edges in a moment.
Step 9: Solving an Unexpected Problem
If the can metal is too thin the wheel will start popping in and out while the hamster runs on it. To avoid nasty vibrations and early failure, cut a circular piece of plastic sheet, or attach some sticks of a rigid material and attach it to the bottom of the can.
Step 10: Fixing to the Spindle
Using hot glue secure the spindle is in place, verifying the alignment. Hold the spindle with one hand and spin the wheel with the other. No vibrations or unbalanced movement should occur.
Step 11: Padding and Other Finishing
Before mounting I suggest you to use foamy to carpet the wheel and give the hamster a better place to step on.
Step 12: Padding (cont.)
I was afraid that glue solvents could harm Pachita, so I decided to use electrical tape to keep the foamy in place. An advantage of the tape is that it allows to remove and replace the foamy if the hamster chews it.
Step 13: Fastening to the Cage
Use some metal wire or zip ties to fasten the wheel to the cage. Don’t mind the cables connected to the spindle, I soldered them as an experiment (see the end of the post) and are absolutely no required for the wheel to work.
Step 14: Testing
And that’s how the finished product looks. It’s a total success! Besides of the noiseless operation you may notice that the hamster is running faster than usual. That’s because of the low friction and high quality of the spindle bearings.
Step 15: Measuring the Hamster Speed, and Other Stuff
I have mentioned that connecting wires to the spindle may be useful for experimenting. As you already may know, the spindle is a three-phase motor and can be used as a generator too. It will generate AC current as it spins. which can be connected to a three phase rectifier to obtain DC current as the hamster runs.
I was tempted to make a separate guide about this, but for my needs I found it's useless. The generated AC voltage is almost insignificant, and it's further reduced due the diode voltage drop. Don’t expect to get any more than 13.9 millivolts DC with a hamster running at full speed.
That said, the small generated voltage can be amplified with an Op-Amp to drive SOME applications, like a speedometer, a computer program or trigger a decorative circuit. The uses are up to you and your imagination.