Broken Dremel Fix: Battery to Corded

I got these two dremels (broken of course) for about $12 together off ebay, and being pretty handy as an engineering student, I found a pretty cheap way to get them fixed. In short, all it takes is a power supply, a button switch, and a couple wires. This works for both the 5 volt pet nail version (which i use for pictures) and the 7-12 V version. Here's how I did it:

parts used:

broken dremel

4.8V phone charger

some wires

a button switch

tools:

screwdriver with 6 point bit (a flathead can work, maybe even a three point lmk if this one works too!)

solder

soldering iron

Using one of those 6 point screwdriver heads (or a carefully selected flathead if you don't have one of those bits) you can unscrew two screws from the back of your dremel after removing the battery pack and take it apart. Take the directional switch off because it doesn't get used here. Try not to lose the parts toward the thin end of the dremel cause that controls the bits that you can swap in and out for your own projects. The dremel might not be so handy anymore if you lose them!

Here is where the magic happens. I swapped out the batteries (pinch the parts that lock the batteries into the dremel and pry it apart, the batteries come right out.) and spliced the cable from the phone charger into positive and negative lead. The switch will also need some leads (as pictured in the cover photo of this project) and these can just go between the positive of the motor and the power supply or the negative of the motor and supply.

For the 12V one you may notice I used a female connector that is glued into the battery housing. I simply de-soldered it from a scrapped PCB I had but I'm certain these parts cost a couple cents if you buy one. If not you can just splice a cable directly like the 5V one.

Although the wiring is fairly simple here, it helps to test before you close up the case for this thin:

-Press the button a couple times and see what happens. If the motor whirs as you press, congratulations you're done!

-if it whirs and stops for about a second each, the power supply may be pulsed. You may need a different one or you may want to add a simple low pass filter to your power supply (a resistor and capacitor) This will help steady the output so the motor keeps spinning.

-if nothing happens check your connections. This is the most frustrating part of any project but if you build this habit now it can help save you time in future projects.

Now you're done. Close it up and get to work with your handy new corded dremel!