[Nexus 7 General] pixlgeek:
Ahoy XDA!

First post in the Nexus 7 forums.

So I got fed up with not being able to sleep and wake my device using the flap on my case so I decided to take matters into my own hands.

At first I thought I would sand down a magnet, cut a slit into the side of the rubber far enough to push the magnet through and be done with it. Sanding the magnet took way too long and cutting perfectly straight through the rubber proved to be much more challenging than I anticipated. So use caution if you plan on attempting this method, it didn't work for me and the method I ended up going with was so much cleaner and easier to implement.

I decided to drill a 1/2 inch hole straight through the front flap of the case and insert a neodymium magnet into the hole. Turned out really well. I'll show you the completed project and then a brief description of how I accomplished it. Also check out the video of how it works.

http://www.youtube.com/watch?v=T49Ap83xpiE

Step 1: Acquire Magnets

Head to your local hobby/craft store (I went to Michaels but I'm sure most hobby stores carry these) and find yourself a 1/2 inch neodymium magnets. I got the "ProMag Brand Round Neo Magnets 4-Pack .5 in diameter/12.7 mm diameter". I'm not sure of the height but if you can find this brand, they are the exact same as the front flap on the case.

Step 2: Locate Magnetic Sensor

So I found the sensor to be roughly 4.5 in up from the bottom and 2.5 inches out from the left but please don't rely on these measurements. Test your own device yourself and figure out the best place for the magnet.

Step 3: Mark Your Hole and Drill

So after finding the optimal location for the magnet sensitivity, mark that spot on the inside flap of the smart case. I placed the case on a piece of wood and opened it so that the front of the case is face down (essentially like you would have it if you were using the tablet). I clamped the case into place to prevent it from moving and I then started with a 1/4 inch drill bit and used a power drill to essentially pilot a hole through the case. I don't know if this step was necessary but I find that with a pilot hole the larger bit will not wander as I drill with it. Next I took a 1/2 inch drill bit (into my hand not the power drill) and centered the drill bit into the hole in the case and the small hole that I had made into the wood. I then began to slowly and with even pressure turn the bit in the cutting direction. Do this step slowly and without too much pressure because if the bit bites too hard into the rubber, the case will try to rise and the bit will cut a gash into hole. I clamped around either side of the hole and as close to it as I could to prevent this from happening. After getting through almost all the way by hand on this side of the flap, I turned the case over, centered the hole in the case over the hole in the wood, clamped and started again, even slower this time. I figured any mistakes I made on the front side would look much worse than those on the back. (see first impressions ;) ). So after about 20 minutes or so of this hand drilling I had a rough but even circle. It is important when you drill by hand that you try to keep the bit at a 90 degree angle with the case and dont let it move when you turn it. If it moves the hole will be oblong and look terrible. So like I said I had a nice hole with slightly burred edges.

Step 4: Test Fit, Sand, Test Fit Again, Sand Some More

At this point I positioned the magnet over the hole and forced it into the rough cut hole to get an idea of how much more rubber I would need to remove. It fit but the case would warp a bit because the magnet was slightly too big (Oh the innuendoes that could come from this tutorial). I next too some 50 Grit sandpaper and rolled a torn strip of it into a tight tube, place the tube into the hole and then released the pressure so the tube expanded to the size of the hole. I then pinched the top of the tube and while hold the case just slightly off the edge of the table while still applying firm pressure around the hole so that it wont move, I pushed and pulled the sandpaper tube through the hole to slowly expand it and smooth out the burrs created by the bit. Now take caution in this step because the sandpaper is rolled it will expand as you sand so every minute or so, take the magnet and keep test fitting to get a nice snug fit. You don't want the hole so big that the magnet can fall through. I made mine just tight enough that I have to apply pressure to the magnet and it literally pops in and pressure from the rubber holds it in place.

Step 5: Smooth With XACTO Knife

So after getting the perfect sized hole for your magnet, you will still probably have some small pieces of rubber, we'll call it flash, on the inside rim of the hole. Take your XACTO knife and CAREFULLY trim these flashings away. Apply barely any pressure as they will be quite thin and you don't want to change the shape of the hole or cut into your case. Use whatever method you need to smooth out the hole whether it is cutting or scraping I used a bit of both, but however you do it you should come out with something similar to this.

Step 6 (Optional): Sand and Rubber Coat the Inside of the Magnet

I figured metal against glass may not be the best thing in the event you store your tablet in a bag with other things, so I opted to plasti-dip/rubber coat the side of the magnet that could potentially make contact with the screen. It's pretty simple and you can find a can of this stuff for pretty cheap at your local hardware store. I didn't want to do both sides because I thought the silver looked pretty nice on the outside but do both sides if you prefer it black all around. Keep in mind when you spray, don't get any on the sides of the magnet if you can help it. This will change the outer diameter causing a misfit on the hole we just made.

I took some more sand paper and gave the side I planned to paint a which scuffing so that the paint would stick better and then gave a few short and light bursts, just enough to make a coat. I let it dry for about a half hour and then test fit once more.

Word of caution, when you sand a magnet, the shavings will then feel the need to stick to the magnet. I found the best way to get these off is to scoop them all into a pile on one side of the magnet, then take the sprayer extension on your sink and spray them off with the high pressure water. Make sure before you paint that you get all the shavings off of the side you plan on painting as this could potentially scratch your screen.

Step 7: Test Fit Once More and Glue

So this could be the most critical step of all. Adhesion. Once you glue the magnet in place, you are basically committing. Also, because of the tight fit, adding too much glue will cause leaking and make a mess all over the case, which will look ugly and be a pain to take off. So the key in this step is LESS IS MORE.

Test fit your magnet once more. Lay your case open on a flat surface and push the magnet in. Check both sides ensuring that it does not stick out and no gaps are formed. Make sure the case does not warp with the magnet in and go ahead and test it out with your tablet in the case. This is your last chance to work out any kinks before gluing.

BEFORE PROCEEDING MAKE SURE YOU REMOVE YOUR TABLET FROM THE CASE AND TAKE IT FAR FAR AWAY FROM THE GLUE AND YOUR HANDS.

I used a Gel Super Glue. I highly recommend this because it wont run and won't make a mess. I positioned my case open on the flat surface on top of a piece of wood in the same fashion it would be open if I were using it. Here comes the tricky part. Get yourself a toothpick and put a few drops of the superglue on a piece of cardboard. While holding the magnet in between your fingers so that you can look at the edge, dip your toothpick into the glue so that only the slightest coating of glue is on it. I would say even a full drop of glue is far too much. Just a light coat on the end of the toothpick. Run the toothpick along the outer rim of the magnet quickly but cautiously, avoid getting it on either of the faces of the magnet. Once you have your coating, carefully position the magnet over the hole, and here come the tricky part, you want to try to place the magnet on top of the hole without touching the glue on the sides. I sort of dropped it onto the hole and moved it to center then quickly pushed it into the hole. Once you have it in place ensure that it is flat and even with the case. Check to make sure that the glue hasn't leaked but if it has DO NOT TRY TO WIPE IT OFF. Allow the glue to dry, it will be much easier to chip or sand off later than to clean a super glue smear off of the rubber.

At this point your case should be looking pretty good. Don't move it until you've given the glue enough time to dry and definitely do not test it with your tablet in place until it has dried.

I hope this post helps some of you and if you have questions before doing this or while you are in the process, please let me know and I will do what I can to help.

-Pixlgeek