MagSafe for the Rest of Us: a DIY Magnetic Power Adaptor

We all know that one of the most common places for a laptop to break is its power adaptor. The combination of being directly attached to the motherboard, heat, and constant moving and shifting leads the connector to become loose and sloppy. Eventually the connection stops working altogether. Apple has solved this problem on their laptops by use of a magnetic power adaptor, unfortunately for us they also patented the idea.

This is my version of a magnetic power adaptor for an Acer 1410 laptop, You should be able to modify the steps fairly easily for work for any laptop though. It is effective, easy to build with common materials, and takes the strain off of the internal connection and motherboard. It also holds on well enough to not come off unless it is supposed to.

Edit: There have been some changes to the design, mostly involving using thin copper foil in place of aluminum duct tape. There were heat issues involving the aluminum tape, these issues have been resolved by swapping out the aluminum tape for copper foil. Thanks to instructables members jeff-o and CyberBill for their insights and suggestions.

This modification should be completely reversible and do no harm to the laptop or original power adaptor.

Please always take your time to work safe and unplug the power cord and laptop battery.

A big thanks goes to breath for his original ThinkSafe instructable located here:
ThinkSafe: A Magnetic Power Connector for Thinkpads

You will need:

Tools:

Pliers
Wire cutters
Scissors
Flashlight
Matchsticks (to apply epoxy)

Materials:

Neodymium Ring-Shaped Magnets (enough to cover your adaptor plug with some overhang)
Wire Studs (to fit into the power socket)
Steel Washers (asst. sizes, make sure your magnets will STICK to them)
Thin Copper Foil (Note: aluminum duct tape has too much resistance)
Electrical Tape
Two-Part Epoxy Adhesive
Nail(s)
Calming Incense (to keep you sane while working with the fiddly bits)

My design for building this adaptor changed many times throughout the build due to trial and error, it is best to start out with too many pieces and then narrow it down to what you actually need than to be stuck without a part you really need.

Cost Breakdown:
Magnets: $2.45 each
Wire Studs: $1.65 for 10
Epoxy: $5
Copper Foil: $10
Various Washers and Nails: $4
Incense: $1.95

Total Cost: ~$32 CDN

The first thing to do is cut yourself a piece of the copper foil that is just wide enough to cover the metal part of your power adaptors plug. This is to remove any gap between the adaptor plug and the Ring Magnets. I cut my copper sheet width-wise and it was more than long enough.

Wrap this piece around the plug until it is wide enough that the Ring Magnets will fit snugly.

Next, fit your magnets, if there is a space between the plastic of the plug and the back of your magnets you should add a washer so that when it comes time to epoxy them, the epoxy will have more to hold on to.
I used 4x Magcraft brand Ring-Shaped neodymium magnets, size 0.500 x 0.125 x 0.250", Part number NSN0814.  

Push the magnets onto the plug. You may find it easiest to have the copper hanging over the edge of the plug and then to put the magnets over the copper and press the two sides together for a snug fit.

The most important thing is that your magnets have some overhang over the edge of the adaptor, this is so that the Center Power Pin you will make in the next step wont be openly exposed which could lead to a short circuit.

Now cut off any excess copper so that it fits below the edge of the power adaptor.

You are now ready to make your Center Power Pin.

Now we will build the pin that will allow power to reach the center pin connected to the socket on the laptop.

First find a nail thats width is a comfortable fit inside the hole in the power adaptor. It should fit tightly but not require too much force to push in. Also the head should be large enough to provide a good contact surface while being small enough that it fits inside the magnet rings without coming in contact with them. The head should also be flat and the nail must be made out of a conductive material.

When you have found the perfect nail cut it to a length that will fit flush with the end of the power adaptor. It doesn't have to reach all the way to the back of the adaptor nor should it, just cut it so it will sit inside a ways and make contact with the internal connectors. 

Press the nail head flush with the adaptor and your power adaptor is complete.

When you are sure it all works epoxy the back magnet to the washer/plastic of the adaptor plug, the rest of the magnets will stay together by magnetism.

This one took me a few tries to get just right.

First things first. You need something that will fit into the power adaptor socket on the laptop. I used some wire studs from Pico of Canada, part number 1769 DP, size 22-16. They just happened to fit in perfectly and this is where going to a store that sells single bits or that will let you try things works out well. Buy extras of these because you will most likely go through about 6 or so getting it right.

The next thing is to find washers that will fit around your insert. I used one small locking washer to take out the small gap between the plug area and the rest of the laptop side, and a larger one to have my magnets attach to. Again make sure they are magnetic AND conductive.

Ignore the piece of aluminum tape in the pictures I was just using it to test the connectivity of the pieces.

After you have found your washers the next step is to separate the 2 pieces of the Wire Stud, I accomplished this using a pair for pliers to push the metal pin out of the bottom of the plastic body.

On to Part 2.

First, cut another piece of copper foil, this time to fit the plastic piece from the Wire Stud. Wrap the plastic piece in the foil until it is wide enough that the small washer fits snugly over it.

Epoxy the small washer to the copper foil, leaving enough space so that when you epoxy the larger washer over it, the larger washer will sit flush with the end of the plastic piece.

The important thing with this step is that you make sure the outer washer connects to the ground connection inside the power adaptor socket on the laptop. The best way to achieve this is to epoxy the small washer so that it is touching the Copper Foil wrapped around the plastic piece. And then to epoxy the larger washer so that it is in direct metal to metal contact with the small washer. 

In the end the whole thing should fit flush to the side of your laptop

On to Part 3

Now you have to cut your center pin for the socket side.

This part is tricky as getting the length right can be a bit tedious, this is why I said to get extra wire studs. I went through about 6 before i got the perfect length

The first thing to do is put the pin from the Wire Stud into the socket, the hollow side should fit over the stock socket center pin easily. You may want to crimp the hollow end a bit to give it a tighter hold on the stock center pin.

Now put in the insert you made in the last step.

Next is to slowly cut bits of the center pin off, testing with your plug adaptor to make sure you haven't cut too much off.  Stop when you reach a length that allows your magnets to sit flush with the large washer of the insert while still allowing the center pins to make a connection.

When you find the right length you should wrap the pin with a bit of electrical tape to keep it from shorting out on the sides of the magnets when it is charging. Just be sure to leave the tip exposed.

Once you are close to the right length it may help to epoxy the socket insert down and leave the magnets un-epoxied. That way you have a bit of play on the magnet side to adjust and ensure a connection before you finalize the whole deal.

When you epoxy the insert down make sure it is sitting flush and hold it for a few minutes until it sets.

I would suggest that when you epoxy the insert down you take care not to get any epoxy into the actual socket of the laptop, just try to keep it only on the underside of the larger washer. This will make removal easier if it becomes necessary. 


Ensure it is all functional and epoxy down your magnets and you're done!

You're done!

Now you can trip over your cord as much as you want.

Also i don't see how Apple has a patent on this idea when they stole the idea from Japanese deep fryers. oh well.

Anyways happy modding!

I had to remove this mod once I had finished it to make changes to the design, these are shots of after the modifications were removed and before the changes in design were implemented. As you can see there are no permanent marks or damage to the original power adaptor or charging port on the laptop